Table of Contents

Table of Contents

FORWARD-LOOKING STATEMENTS

This quarterly report on Form 10-Q of Cellectar Biosciences, Inc. (the “Company”, “Cellectar”, “we”, “us”, “our”) contains forward-looking statements within the meaning of Section 21E of the Securities Exchange Act of 1934, as amended, which we refer to as the Exchange Act. Examples of our forward-looking statements include:

Table of Contents

In some cases, you can identify forward-looking statements by terminology, such as “expects,” “anticipates,” “intends,” “estimates,” “plans,” “believes,” “seeks,” “may,” “should,” “could”, “would” or the negative of such terms or other similar expressions. Accordingly, these statements involve estimates, assumptions and uncertainties that could cause actual results to differ materially from those expressed in them. Forward-looking statements also involve risks and uncertainties, many of which are beyond our control. Any forward-looking statements are qualified in their entirety by reference to the factors discussed throughout this quarterly report.

You should read this report completely and with the understanding that our actual future results may be materially different from what we expect. You should assume that the information appearing in this report is accurate as of the date hereof only. Because the risk factors referred to herein could cause actual results or outcomes to differ materially from those expressed in any forward-looking statements made by us or on our behalf, you should not place undue reliance on any forward-looking statements. Further, any forward-looking statement speaks only as of the date on which it is made, and we undertake no obligation to update any forward-looking statement to reflect events or circumstances after the date on which the statement is made or to reflect the occurrence of unanticipated events. New factors emerge from time to time, and it is not possible for us to predict which factors will arise. In addition, we cannot assess the impact of each factor on our business or the extent to which any factor, or combination of factors, may cause actual results to differ materially from those contained in any forward-looking statements. We qualify all

This quarterly report on Form 10-Q contains trademarks and service marks of the information presentedCellectar Biosciences, Inc. Unless otherwise provided in this quarterly report and particularly our forward-looking statements,on Form 10-Q, trademarks identified by these cautionary statements.™ are trademarks of Cellectar Biosciences, Inc. All other trademarks are the property of their respective owners.

​

Table of Contents

PART I. FINANCIAL INFORMATION

CELLECTAR BIOSCIENCES, INC.

CONDENSED CONSOLIDATED BALANCE SHEETS

​

​

The accompanying notes are an integral part of these condensed consolidated financial statements.

​

Table of Contents

CELLECTAR BIOSCIENCES, INC.

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS

(UNAUDITED)

​

​

The accompanying notes are an integral part of these condensed consolidated financial statements.

​

Table of Contents

CELLECTAR BIOSCIENCES, INC.

CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY
(UNAUDITED)

(UNAUDITED)​

​

The accompanying notes are an integral part of these condensed consolidated financial statements.

​

Table of Contents

CELLECTAR BIOSCIENCES, INC.

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS
(UNAUDITED)

(UNAUDITED)​

​

The accompanying notes are an integral part of these condensed consolidated financial statements.

​

Table of Contents

CELLECTAR BIOSCIENCES, INC.

NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (UNAUDITED)

1. NATURE OF BUSINESS AND ORGANIZATION

Cellectar Biosciences, Inc. (the “Company”) is a late-stage clinical biopharmaceutical company focused on the discovery and development of drugs for the treatment of cancer leveraging our proprietary phospholipid drug conjugate™ (PDC™) delivery platform that are designed to specifically targets cancer cells and deliverdelivers improved efficacy and better safety as a result of fewer off-target effects.

The Company has incurred losses since inception in devoting substantially all of its efforts toward research and development and has an accumulated deficit of approximately $133,132,597 at$157,038,000 as of March 31, 2021.2022. During the three months ended March 31, 2021,2022, the Company generated a net loss of approximately $6,357,170$6,140,000 and expects that it will continue to generate operating losses for the foreseeable future. However, the Company believes that its cash balance atas of March 31, 20212022 is adequate to fund ourits basic budgeted operations for at least 12 months from the filing of these financial statements. Thestatements.The Company’s ability to execute its current operating plan depends on its ability to obtain additional funding via the sale of equity and/or debt securities, a strategic transaction or otherwise. The Company plans to continue to actively pursue financing alternatives, but there can be no assurance that it will obtain the necessary funding.

The accompanying Condensed Consolidated Balance Sheet as of December 31, 20202021 has been derived from the Company’sour audited financial statements. The accompanying unaudited Condensed Consolidated Balance Sheet as of March 31, 2021,2022, and the Condensed Consolidated Statements of Operations, the Condensed Statements of Stockholders’ Equity and, the Condensed Consolidated Statements of Cash Flows, and the Consolidated Statements of Stockholders’ Equity for the three months ended March 31, 20212022 and 2020,2021, and the related interim information contained within the notesNotes to the Condensed Consolidated Financial Statements, have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) for interim financial information and with the instructions, rules and regulations of the Securities and Exchange Commission (“SEC”) for interim financial information. Accordingly, they do not include all the information and the notes required by U.S. GAAP for complete financial statements. In the opinion of management, the unaudited interim condensed consolidated financial statements reflect all adjustments which are of a nature necessary for the fair presentation of the Company’s consolidated financial position at March 31, 20212022 and consolidated results of its operations, cash flows, and stockholders’ equity and cash flows for the three months ended March 31, 20212022 and 2020.2021. The results for the three months ended March 31, 20212022 are not necessarily indicative of future results.

These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and related notes thereto included in the Company’s Form 10-K for the fiscal year ended December 31, 2020,2021, which was filed with the SEC on March 2, 2021.21, 2022.

Principles of Consolidation — The consolidated financial statements include the accounts of the Company and the accounts of its wholly-owned subsidiary. All significant intercompany accounts and transactions have been eliminated in consolidation.

Fixed Assets — Property and equipment are stated at cost. Depreciation on property and equipment is provided using the straight-line method over the estimated useful lives of the assets (3(3 to 10 years). Because of the significant value of leasehold improvements purchased, leasehold improvements are depreciated over 64 months (their estimated useful life), which represents the full term of the lease. Our only long-lived assets are property and equipment. The Company periodically evaluates long-lived assets for potential impairment. Whenever events or circumstances change, an assessment is made as to whether there has been impairment to the value of long-lived assets by determining whether projected undiscounted cash flows generated by the applicable asset exceed its net book value as of the assessment date. There were no0 long-lived fixed asset impairment charges recorded during the three months ended March 31, 2021 or year ended December 31, 2020.2022.

Right-of-Use (ROU)Right-of-Use (ROU) Asset and Lease Liabilities —On January 1, 2019, the -The Company adoptedaccounts for all material leases in accordance with FASB Accounting Standards Codification (“ASC”)(ASC) Topic 842, using the modified retrospective method for all material leases that existed at or commenced after January 1, 2019.Leases. ROU Assets are amortized over their estimated useful life, which represents the full term of the lease.

Stock-Based Compensation — The Company uses the Black-Scholes option-pricing model to calculate the grant-date fair value of stock option awards. The resulting compensation expense for awards that are not performance-based is recognized on a straight-line basis over the service period of the award, which for stock option grants issued in 20212022 and 20202021 ranged from one year to three years for stock options.years.

Table of Contents

Research and Development — Research and development costs are expensed as incurred. ToThe Company recognizes revenue and cost reimbursements from government grants when it is probable that the extent that such costsCompany will comply with the conditions attached to the grant arrangement and the grant proceeds will be received. Government grants are reimbursed byrecognized in the federal governmentCondensed Consolidated Statements of Operations on a fixed price, best effortssystematic basis andover the federalperiods in which the Company recognizes the related costs for which the government grant is intended to compensate. Specifically, when government grants are related to reimbursements for cost of revenues or operating expenses, the sole customer for such research and development, the funding isgovernment grants are recognized as a reduction of research and development expenses.the related expense in the Condensed Consolidated Statements of Operations. The Company records government grants receivable in the Condensed Consolidated Balance Sheets in accounts receivable.

Income Taxes — Income taxes are accounted for using the liability method of accounting. Under this method, deferred tax assets and liabilities are determined based on temporary differences between the financial statement basis and tax basis of assets and liabilities and net operating loss and credit carryforwards using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. Valuation allowances are established when it is more likely than not that some portion of the deferred tax assets will not be realized. Management has provided a full valuation allowance against the Company’s gross deferred tax asset. Tax positions taken or expected to be taken in the course of preparing tax returns are required to be evaluated to determine whether the tax positions are “more likely than not” to be sustained by the applicable tax authority. Tax positions deemed not to meet a more-likely-than-not threshold would be recorded as tax expense in the current year. There wereare no uncertain tax positions that require accrual to or disclosure in the financial statements as of March 31, 20212022 and December 31, 2020.2021.

Fair Value of Financial Instruments — The guidance under FASB ASC Topic 825, Financial Instruments, requires disclosure of the fair value of certain financial instruments. Financial instruments in the accompanying financial statements consist of cash equivalents, prepaid expenses and other assets, accounts payable and long-term obligations. The carrying amount of cash equivalents and accounts payable approximate their fair value as a result of their short-term nature. (See Note 2)

Concentration of Credit Risk — Financial instruments that subject the Company to credit risk consist of cash and cash equivalents on deposit with financial institutions. The Company’s excess cash as of March 31, 20212022 and December 31, 20202021 is on deposit in interest-bearing transaction accounts with well-established financial institutions. At times, such amounts may exceed the FDIC insurance limits. As of March 31, 2021,2022, and December 31, 2020,2021, uninsured cash balances totaled approximately $53,100,000$30,100,000 and $56,700,000,$35,200,000, respectively.

Recently Adopted Accounting Pronouncements - For the fiscal year beginningBeginning January 1, 2021, management early adopted Accounting Standards Update (“ASU”) 2020-06 using the modified retrospective method. ASU 2020-06 simplifies entities’ accounting for convertible instruments by eliminating the cash conversion and beneficial conversion feature (“BCF”)(BCF) models outlined in ASC 470-20 Debt-Debt with Conversion and Other Options.470-20. Under ASU 2020-06, convertible instruments that would have previously been subject to the BCF or cash conversion guidance no longer require separate accounting for the conversion feature. Entities may elect to early adopt ASU 2020-06 for fiscal years beginning after

New Accounting Pronouncements – Issued but Not Yet Adopted — In December 15, 2020. Since the Company early adopted ASU 2020-06 beginning January 1, 2021, the FASB issued ASU No. 2021-10, Government Assistance (Topic 832), which aims to provide increased transparency by requiring business entities to disclose information about certain type of government assistance they receive in the notes to the financial statements. The Company would no longer be requireddoes not expect the adoption of this standard to recognizehave a BCF even when shareholder approval is received. In December 2020, the Company completed a private placement where we issued Series D convertible preferred stock. The preferred shares are convertible into shares of common stock upon receipt of stockholder approval of the issuance of the underlying shares of common stock as required by Nasdaq Marketplace Rule 5635(d) at a special stockholder meeting. The shareholders approved this conversionmaterial impact on February 25, 2021. As such, management will continue to account for the Series D Preferred Stock in equity without any separate accounting for the conversion options.its consolidated financial statements.

2. FAIR VALUE

In accordance with the Fair Value Measurements and Disclosures Topic of the FASB ASC 820, the Company groups its financial assets and financial liabilities generally measured at fair value in three levels, based on the markets in which the assets and liabilities are traded and the reliability of the assumptions used to determine fair value:

Table of Contents

To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The carrying value of cash and cash equivalents approximates fair value as maturities are less than three months. The carrying amounts reported onin the Condensed Consolidated Balance sheets for other current financial assets and liabilities approximate fair value because of their short-term nature.

3. STOCKHOLDERS’ EQUITY

Authorized Share Increase

At a special meeting held on February 25, 2021, the Company’s stockholders approved the amendment of the Company’s Second Amended and Restated Certificate of Incorporation, as amended, to increase the authorized common stock from 80,000,000 shares to 160,000,000 shares.

Equity Distribution Agreement

On August 11, 2020, the Company entered into an equity distribution agreement (the “Sales Agreement”) with Oppenheimer & Co. Inc. (the “Sales Agent”). Pursuant to the Sales Agreement, the Company may offer and sell from time to time through the Sales Agent, up to $14.5 million of shares of the Company’s common stock, par value $0.00001 per share (the “ATM Shares”). The Sales Agent will receive from the Company a commission of 3.0% of the gross proceeds from the sales of the ATM Shares pursuant to the terms of the Sales Agreement. The offering of the ATM Shares pursuant to the Sales Agreement will terminate upon the earliest of (i) the sale of all ATM Shares subject to the Sales Agreement, or (ii) the termination of the Sales Agreement by the Company or the Sales Agent. Net proceeds from the sale of the ATM Shares will be used for general corporate purposes, including working capital.

The ATM Shares issued under the Sales Agreement are offered pursuant to a registration statement on Form S-3, which was declared effective by the SEC on August 20, 2020.

In June 2021, the Company issued and sold an aggregate of 41,692 ATM Shares pursuant to the Sales Agreement and received gross proceeds of approximately $69,000 and net proceeds of $35,000 after deducting commissions to the Sales Agent and other offering expenses.

December 2020 Public Offering and Private Placement

On December 23, 2020, the Company issued and sold 18,148,136 shares of common stock, par value $0.00001 per share, at a public offering price of $1.35 per share of common stock, prior to deducting underwriting discounts and commissions and estimated offering expenses.

In a concurrent private placement, the Company issued and sold 1,518.5181,518.5180 shares of Series D convertible preferred stock. TheThese preferred shares are convertible into a number of shares of common stock equal to $13,500 divided by $1.35 (or 10,000 shares of common stock for each share of Series D preferred stock converted), and were issued at a price of $13,500 per share of Series D preferred stock. The preferred shares willwere only be convertible into common stock upon receipt of stockholder approval of the issuance of the underlying shares of common stock as required by Nasdaq Marketplace Rule 5635(d) at a special stockholder meeting to be called for that purpose. At a special meeting of stockholders held on February 25, 2021, the stockholders approved, in accordance with Nasdaq Listing Rule 5635(d), the issuance of shares of the Company’s common stock upon the conversion of the Series D preferred stock. During the quarterthree months ended March 31, 2021, 574.0736 shares of our Series D convertible preferred stock were converted into 5,740,736 Common Stockshare of common stock at a ratethe established conversion rate. During the three months ended June 30, 2021, 250 shares of 1 to 10,000 shares.

our Series D convertible preferred stock were converted into 2,500,000 of common stock. During the three months ended September 30, 2021, 583.33 shares of our Series D convertible preferred stock were converted into 5,833,333 shares of common stock. There were 0 preferred stock conversions for the three months ended December 31, 2021, or the three months ended March 31, 2022.

The net proceeds of the offeringsDecember public offering and private placement to the Company, after deducting the underwriting discounts and commissions, placement agency fees, and estimated offering expenses payable by the Company, were approximately $41.4 million.

Table of Contents

The common stock issued in the public offering was offered by the Company pursuant to a registration statement on Form S-3, which was declared effective by the SEC on August 20, 2020.

The common stock issuable upon conversion of the Series D preferred Stockstock in the private placement was offered by the Company pursuant to a registration statement on Form S-3, which was declared effective by the SEC on February 1, 2021.

In accordance with the concept of ASC 820 regarding the December 2020 public offering, the Company allocated the value of the proceeds to the common stock and preferred stock utilizing a relative fair value basis. Using the Nasdaq closing trading price for our stock on December 28, 2020, the Company computed the fair value of the shares sold. The fair value of the preferred stock was estimated on a relative fair value basis. This valuation did not impact the total increase to Stockholders’ Equity of $45.0 million, but is an internal, proportionate calculation allocating the gross proceeds of approximately $24.5 million to common stock and $20.5 million to preferred stock.

June 2020 Public Offering

On June 5, 2020, the Company issued and sold 14,601,628 shares of common stock, 2,789,700 pre-funded warrants exercisable for one1 share of our common stock at an exercise price of $0.00001 per share and 8,695,664 Series H warrants to purchase 8,695,664 shares of common stock. The public offering price of a share of common stock together with one-half of a Series H warrant to purchase one share of common stock was $1.15. The public offering price of a pre-funded warrant together with one-half of a Series H Warrant was $1.1499. The Series H warrants have an exercise price of $1.2075 per share and are exercisable for five years from the date of issuance. As of March 31, 2021,2022, all 2,789,700 pre-funded warrants have been exercised. During the three months ended 1,005,320 series H warrants were exercised. As of March 31, 2021,exercised, and a total of 1,487,695 Series H warrants have been exercised.

In accordance with the concept of ASC 820 regarding the June 2020 public offering, the Company allocated value of the proceeds to the common stock and warrants utilizing a relative fair value basis. Using the Nasdaq closing trading price for our stock on June 5, 2020, the Company computed the fair value of the shares sold. The fair value of the warrants was estimated using the Black-Scholes option-pricing model at that same date. This valuation did not impact the total increase to Stockholders’ Equity of $20.0 million, but is an internal, proportionate calculation allocating the gross proceeds of approximately $12.1 million to common stock and $7.9 million to warrants.

Gross offering proceeds to the Company were $20.0 million, with net proceeds to the Company of approximately $18.3 million after deducting placement agent fees and related offering expenses. The Company intends to use the net proceeds from the offering for research and development, funding clinical studies, working capital and general corporate purposes.

The common stock, pre-funded warrants and Series H warrants were offered by the Company pursuant to a registration statement on Form S-1, which was declared effective by the SEC on June 2, 2020 and an additional registration statement filed on June 2, 2020 pursuant to Rule 462(b) under the Act.

Common Stock Warrants

The following table summarizes information with regard to outstanding warrants to purchase common stock as of March 31, 2021.2022:

​

​

Table of Contents

​

4. STOCK-BASED COMPENSATION

Accounting for Stock-Based Compensation

2021 Stock Incentive Plan The 2021 Stock Incentive Plan (the “2021 Plan”) was adopted on June 23, 2021 authorizing an aggregate of 6,000,000 shares of common stock for grants of incentive or nonqualified stock options, rights to purchase restricted and unrestricted shares of common stock, stock appreciation rights and performance share grants. The Compensation Committee determines exercise prices, vesting periods and any performance requirements on the date of grant, subject to the provisions of the 2021 Plan. Options are granted at or above the fair market value of the common stock at the grant date and expire on the tenth anniversary of the grant date. Vesting periods are generally between one and three years. Options granted pursuant to the 2021 Plan generally will become fully vested upon a termination event occurring within one year following a change in control, as defined. A termination event is defined as either termination of employment or services other than for cause or constructive termination of employees or consultants resulting from a significant reduction in either the nature or scope of duties and responsibilities, a reduction in compensation or a required relocation. All outstanding awards under the 2015 Stock Incentive Plan (the “2015 Plan”) remained in effect according to the terms of the 2015 Plan and the respective agreements relating to such awards. In addition, any shares that are currently available under the 2015 Plan and any shares underlying awards under the 2015 Plan which are forfeited, cancelled, reacquired by the Company or otherwise terminated will be added to the number of shares available for grant under the 2021 Plan. As of March 31, 2022, there are an aggregate of 1,605,449 shares available for future grants under the 2021 Plan.

During the three-month periodsperiod ended March 31, 20212022 and 2020,2021, options granted were 208,5002,778,500 and 273,750,208,500, respectively. The following table summarizes amounts charged to expense for stock-based compensation related to employee and director stock option:option grants:

​

​

On March 4, 2021, the Companywe granted 2,810,000 contingent non-statutory stock option awards at an exercise price of $1.74 per share to our employees. Each of these grants iswas contingent on approval of the 2021 Stock Incentive Plan that is to bewas voted uponon and approved by the stockholders at the Annual Meeting of Stockholders to be held on June 23, 2021. Until such time thatIn accordance with the timing of the stockholder approval, the Company recognized the compensation expense of the contingent non-statutory stock option awards are approved by stockholders, no expense will be accrued byissued in March 2021 beginning in June 2021 and continuing through the Company.

remaining vesting period.

Assumptions Used in Determining Fair Value

Valuation and amortization method. The fair value of each stock award is estimated on the grant date using the Black-Scholes option-pricing model. The estimated fair value of employee stock options is amortized to expense using the straight-line method over the required service period which is generally the vesting period. The estimated fair value of the non-employee options is amortized to expense over the period during which a non-employee is required to provide services for the award (usually the vesting period).

Volatility. The Company estimates volatility based on the Company’s historical volatility since its common stock is publicly traded.

Risk-free interest rate. The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant commensurate with the expected term assumption.

Expected term. The expected term of stock options granted is based on an estimate of when options will be exercised in the future. The Company applies the simplified method of estimating the expected term of the options, as described in the SEC’s Staff Accounting Bulletins 107 and 110, as the historical experience is not indicative of the expected behavior in the future. The expected term,

Table of Contents

calculated under the simplified method, is applied to groups of stock options that have similar contractual terms. Using this method, the expected term is determined using the average of the vesting period and the contractual life of the stock options granted. The Company applied the simplified method to non-employees who have a truncation of term based on termination of service and utilizes the contractual life of the stock options granted for those non-employee grants which do not have a truncation of service.

Forfeitures.The Company records stock-based compensation expense only for those awards that are expected to vest. The Company accounts for forfeitures as they occur.

Dividends. The Company has not historically recorded dividends related to stock options.

Exercise prices for all grants made during the three months ended March 31, 2022 and March 31, 2021 were equal to the market value of the Company’s common stock on the date of grant.

Stock Option Activity

A summary of stock option activity is as follows:

​

​

The aggregate intrinsic value of options outstanding is calculated based on the positive difference between the estimated per-share fair value of common stock at the end of the respective period and the exercise price of the underlying options. There have been no option exercises to date. Shares of common stock issued upon the exercise of options are from authorized but unissued shares.

As of March 31, 2021,2022, there was approximately $968,000$2,800,400 of total unrecognized compensation cost related to unvested stock-based compensation arrangements. Of this total amount, the Company expects to recognize approximately $388,000, $392,000, $173,000,$1,092,300, $1,193,600, $489,500, and $15,000$25,000 during 2021, 2022, 2023, 2024, and 20242025 respectively. The Company’s expense estimates are based upon the expectation that all unvested options will vest in the future. The weighted-average grant-date fair value of vested and unvested options outstanding at March 31, 2022 was $2.43 and $0.68, respectively. As of March 31, 2021, wasvested and unvested options were $5.84 and $1.38, respectively.

Restricted Stock Grants. During 2017, the Company issued 46,000 shares under the 2015 Plan of restricted common stock with a weighted average grant date fair value of $20.96. The shares vested annually over a three year period. The following table summarizes the restricted stock grants:

​

5. INCOME TAXES

The Company accounts for income taxes in accordance with the liability method of accounting. Deferred tax assets or liabilities are computed based on the difference between the financial statement and income tax basis of assets and liabilities, and net operating loss carryforwards (“NOLs”), using the enacted tax rates. Deferred income tax expense or benefit is based on changes in the asset or liability from period to period. The Company did not record a provision or benefit for federal, state or foreign income taxes for the three months ended March 31, 20212022 or 20202021 because the Company has experienced losses on a tax basis since inception. Because of the limited operating history, continuing losses and uncertainty associated with the utilization of the NOLs in the future, management has provided a full allowance against the value of its gross deferred tax assets.

Table of Contents

The Company also accounts for the uncertainty in income taxes related to the recognition and measurement of a tax position taken or expected to be taken in an income tax return. The Company follows the applicable accounting guidance on derecognition, classification, interest and penalties, accounting in interim periods, disclosure and transition related to the uncertainty in income tax positions. No uncertain tax positions have been identified.

6. NET LOSS PER SHARE

Basic net income (loss)loss per share is computed by dividing net income (loss)loss by the weighted average number of shares of common stock outstanding during the period. Diluted net income (loss)loss per share for the three months ended March 31, 20212022 and March 31, 20202021 is computed by dividing net income (loss)loss by the sum of the weighted average number of shares of common stock and the dilutive potential common stock equivalents then outstanding. Potential common stock equivalents consist of stock options, warrants, non-vested restricted stock, preferred shares convertible into common stock and, pre-funded warrants. Since there is a net loss attributable to common stockholders for the three months ended March 31, 20212022 and March 31, 2020,2021, the inclusion of common stock equivalents in the computation for that period would be antidilutive.

The following potentially dilutive securities have been excluded from the computation of diluted net income (loss)loss per share since their inclusion would be antidilutive:

​

​

7. COMMITMENTS AND CONTINGENCIES

Real Property Leases

Florham Park, New Jersey

On June 4, 2018, the Company entered in an Agreement of Lease for 3,893 square feet for its corporate headquarters in Borough of Florham Park, New Jersey.Jersey (the “HQ Lease”). The leaseHQ Lease commencement date was October 2018 and terminates in February 2024. The Company has an option to extend the term of the leaseHQ Lease for one additional 60-month period.

Under the terms of the lease,HQ Lease, the Company paid a security deposit of $75,000 and the aggregate rent due over the term of the leaseHQ Lease is approximately $828,000, which will be reduced to approximately $783,000 after certain rent abatements. The Company is required to pay its proportionate share of certain operating expenses and real estate taxes applicable to the leased premises. After certain rent abatements the rent is approximately $12,500 per month for the first year and then escalates thereafter by 2% per year for the duration of the term.

Madison, Wisconsin

The Company presently rents office space in Madison and is rented for approximately $3,000 per month under an agreement that expires on August 31, 2021.

2022.

Operating Lease Liability

In June 2018, the Company executed an agreement for office space inentered into the Borough of Florham Park, Morris County, New Jersey to be used as its headquarters (“HQ Lease”).Lease. The HQ Lease commenced upon completion of certain improvements by the landlord in October 2018 and terminates in February 2024 with an option to extend the term of the lease for one additional 60-month period. As of December 31, 2018, the Company recorded a deferred lease liability of approximately $176,000 for the improvements funded by the landlord on the consolidated balance sheet. The Company amortizes the deferred liability as a reduction to rent expense in the consolidated statement of operations over the term of the lease.

Table of Contents

Under the HQ Lease, the Company will pay monthly fixed rent based on approximate rate per rentable square foot which ranges between approximately $12,400 to $13,600 over the lease period. In addition, the Company received certain rent abatements and lease incentives subject to the limitations in the HQ Lease. The HQ Lease’s net ROU asset and lease liability are approximately $264,000$183,000 and ($393,000)269,000), respectively, as of March 31, 20212022 and rental expense for the three months ended March 31, 20212022 is approximately $28,000.

Discount Rate

The Company has determined the interest rate implicit in the lease considering factors such as Company’s credit rating, borrowing terms offered by the U.S. Small Business Administration, amount of lease payments, quality of collateral and alignment of the borrowing term and lease term. The Company considers 10% per annum as reasonable to use as the incremental borrowing rate for purposes of the calculation of lease liabilities.

Maturity Analysis of Short-Term and Operating Leases

The following table approximates the dollar maturity of the Company’s undiscounted payments for its short-term leases and operating lease liabilities as of March 31, 2021:2022:

​

​

Legal

The Company may be involved in legal matters and disputes in the ordinary course of business. We do not anticipate that the outcome of such matters and disputes will materially affect the Company’s financial statements.

​

Table of Contents

​

Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations

8. LOAN PAYABLEOverview

On April 21, 2020,You should read the Company received loan proceedsfollowing discussion and analysis of our financial condition and results of operations together with the unaudited financial information and notes thereto included in this Quarterly Report on Form 10-Q. Some of the information contained in this discussion and analysis or set forth elsewhere in this Quarterly Report, including information with respect to our plans and strategy for our business, include forward-looking statements that involve risks and uncertainties. As a result of many factors, including those factors set forth in the amount of approximately $184,000 under the Paycheck Protection Program (“PPP”). The PPP, established as part of the Coronavirus Aid, Relief and Economic Security Act (“CARES Act”), provides for loans to qualifying businesses for amounts up to 2.5 times of the average monthly payroll expenses of the qualifying business. The loans and accrued interest are forgivable after 24 weeks as long as the borrower uses the loan proceeds for eligible purposes, including payroll, benefits, rent and utilities, and maintains its payroll levels. The amount of loan forgiveness will be reduced if the borrower terminates employees or reduces salaries during the 24-week period.

The unforgiven portion of the PPP loan is payable over two years at an interest rate of 1%, with a deferral of payments“Risk Factors” section in our Annual Report on Form 10-K for the first six months. The Company intends to useyear ended December 31, 2021, our actual results could differ materially from the proceeds for purposes consistent withresults described in or implied by the PPP requirements. On December 30, 2020,forward-looking statements contained in the principal loan amount of $184,000following discussion and accrued interest of $1,280 were forgiven, and recognized as a gain on extinguishment of debt.

9. SUBSEQUENT EVENTS

On April 1, 2021, the Company’s October 2015 Private Placement Series A warrants expired and on April 20, 2021, the Company’s April 2016 Underwritten Registered Series A warrants expired.

Overview

We are a late-stage clinical biopharmaceutical company focused on the discovery, development and developmentcommercialization of drugs for the treatment of cancer. Our core objective is to leverage our proprietary PDCphospholipid drug conjugate™ (PDC™) delivery platform to develop PDCs that are designed to specifically target cancer cells and deliver improved efficacy and better safety as a result of fewer off-target effects. OurWe believe that our PDC platform possesses the potential for the discovery and development of the next generation of cancer-targeting treatments, and we plan to develop PDCs both independently and through research and development collaborations.

The COVID-19 pandemic, including variants thereof, has created uncertainties in the expected timelines for clinical stage biopharmaceutical companies such as ours,us, and because of such uncertainties, it is difficult for us to accurately predict expected outcomes. WeWhile we have not yetcommenced dosing in our CLOVER-WaM pivotal clinical study of iopofosine in Waldenstrom’s macroglobulinemia (WM), we have experienced any significant impactsmaterial delays in patient recruitment and enrollment as a result of continued resourcing issues related to COVID-19 at study sites and potentially resulting from concerns among patients about participating in clinical studies during a public health emergency. The COVID-19 pandemic is also affecting the pandemic. However,operations of third parties upon whom we rely. We are unable to predict how the COVID-19 pandemic may impactaffect our future ability to recruit patients forsuccessfully progress our CLOVER-WaM pivotal clinical study or any other clinical programs in the future. Moreover, there remains uncertainty relating to the trajectory of the pandemic and whether it may cause further delays in patient study recruitment. The impact of related responses and disruptions caused by the COVID-19 pandemic may result in difficulties or delays in initiating, enrolling, conducting or completing our planned and ongoing studies obtain adequateand the incurrence of unforeseen costs as a result of disruptions in clinical supply of CLR 131iopofosine or preclinical study or clinical study delays and our ability to obtain additional financing.

Our lead PDC therapeutic, CLR 131 is a small-molecule PDC The continued impact of COVID-19 on results will largely depend on future developments, which are highly uncertain and cannot be predicted with confidence, such as the ultimate geographic spread of the disease or variants thereof, the duration of the pandemic, vaccination rates, travel restrictions and social distancing in the U.S., Canada and other countries, business closures or business disruptions, the ultimate impact on financial markets and the global economy, and the effectiveness of actions taken in the U.S., Canada and other countries to contain and treat the disease. In October 2021, we announced that we are collaborating with BBK Worldwide to provide new concierge services for patients participating in our clinical studies. These services are designed to provide targeted delivery of iodine-131 directlyimprove patients’ and their caregivers’ access to cancer cells, while limiting exposure to healthy cells. We believe this profile differentiates CLR 131 from many traditional on-market treatments. CLR 131 is currently being evaluated in the CLOVER-WaM Phase 2 pivotal study in patients with relapsed/refractory (r/r) Waldenstrom’s macroglobulinemia (WM), a Phase 2B study in r/r multiple myeloma (MM) patientshigh quality care and the CLOVER-2 Phase 1 studyinnovative treatments for a variety of pediatric cancers.

The CLOVER-1 Phase 2 study met the primary efficacy endpoints from the Part A dose-finding portion, conducted in r/r B-cell malignancies. The CLOVER-WaM Study is a pivotal registration study currently evaluating CLR 131 in Bruton tyrosine kinase inhibitor (BTKi) failed or suboptimal response in WM. The CLOVER-1 Phase 2B study is ongoing where CLR 131 remains under further evaluation in highly refractory multiple myeloma (MM) patients.

The CLOVER-2 Phase 1 pediatric study is an open-label, sequential-group, dose-escalation study to evaluate the safety and tolerability of CLR 131 in children and adolescents with relapsed or refractory cancers, including malignant brain tumors, neuroblastoma, sarcomas, and lymphomas (including Hodgkin’s lymphoma). The study is being conducted internationally at seven leading pediatric cancer centers.

their cancer.

The U.S. Food and Drug Administration (“FDA”)(FDA) granted CLR 131iopofosine Fast Track Designation for lymphoplasmacytic lymphoma (LPL) and WM patients having received two or more prior treatment regimens, as well as r/r MMrelapsed or refractory (r/r) multiple myeloma (MM) and r/r diffuse large B-cell lymphoma (DLBCL). Orphan Drug Designations (ODDs) have been granted for LPL/WM, MM, neuroblastoma, soft tissue sarcomas including rhabdomyosarcoma, Ewing’s sarcoma and osteosarcoma. CLR 131Iopofosine was also granted Rare Pediatric Disease Designation (RPDD) for the treatment of neuroblastoma, rhabdomyosarcoma, Ewing’s sarcoma and osteosarcoma. The European Commission granted an ODDsODD for r/r MM and WM.

Our product pipeline also includes one preclinical PDC chemotherapeutic program (CLR 1900) and several partnered PDC assets. The CLR 1900 Series is being targeted for solid tumors with a payload that inhibits mitosis (cell division) a validated pathway for treating cancers.

We have leveraged our PDC platform to establish three ongoing collaborations featuring four unique payloads and mechanisms of action. Through research and development collaborations, our strategy is to generate near-term capital, supplement internal resources, gain access to novel molecules or payloads, accelerate product candidate development, and broaden our proprietary and partnered product pipelines.

Table of Contents

Our PDC platform providesis designed to provide selective delivery of a diverse range of oncologic payloads to cancerous cells, whether a hematologic cancer or solid tumor, a primary tumor, or a metastatic tumor and cancer stem cells. The PDC platform’s mechanism of entry doesis designed not to rely upon specific cell surface epitopes or antigens as are required by other targeted delivery platforms. Our PDC platform takes advantage of a metabolic pathway utilized by all tumor cell types in all stages of the tumor cycle. Tumor cells modify specific regions on the cell surface as a result of the utilization of this metabolic pathway. Our PDCs are designed to bind to these regions and directly enter the intracellular compartment. This mechanism allows the PDC molecules to accumulate in tumor cells over time, which we believe can enhance drug efficacy, and to avoid the specialized highly acidic cellular compartment known as the lysosome,lysosomes, which allows a PDC to deliver molecules that previously could not be delivered. Additionally, molecules targeting specific cell surface epitopes face challenges in completely eliminating a tumor because the targeted antigens are limited in the total number on the cell surface, have longer cycling time from internalization to being present on the cell surface again and available for binding and are not present on all of the tumor cells in any cancer. This means a subpopulation of tumor cells always exist that cannot be targeted by therapies targeting specific surface epitopes. In addition to the benefits provided by the mechanism of entry, PDCs offer the ability to conjugate payload molecules in numerous ways, thereby increasing the types of molecules selectively delivered via the PDC.

The PDC platform features include the capacity to link with almost any molecule, provide a significant increase in targeted oncologic payload delivery and the ability to target all types of tumor cells. As a result, we believe that we can generate PDCs to treat a broad range of cancers with the potential to improve the therapeutic index of oncologic drug payloads, enhance or maintain efficacy while also reducing adverse events by minimizing drug delivery to healthy cells, and increasing delivery to cancerous cells and cancer stem cells.

We employ a drug discovery and development approach that allows us to efficiently design, research and advance drug candidates. Our iterative process allows us to rapidly and systematically produce multiple generations of incrementally improved targeted drug candidates.

In June 2020, the European Medicines Agency’sAgency (EMA) Micro, Small and Medium-sized Enterprise office granted us Small and Medium-Sized Enterprise (SME) status.status by the EMA’s Micro, Small and Medium-sized Enterprise office. SME status allows us to participate in significant financial incentives that include a 90% to 100% EMA fee reduction for scientific advice, clinical study protocol design, endpoints and statistical considerations, quality inspections of facilities and fee waivers for selective EMA prepre- and post-authorization regulatory filings, including orphan drug and PRIME designations. We are also eligible to obtain EMA certification of quality and manufacturing data prior to review of clinical data. Other financial incentives include EMA-provided translational services of all regulatory documents required for market authorization, further reducing the financial burden of the market authorization process.

A description of our PDC product candidates follows:

Clinical Pipeline

Our lead PDC therapeutic, CLR 131iopofosine, is a small-molecule PDC designed to provide targeted delivery of iodine-131 directly to cancer cells, while limiting exposure to healthy cells. We believe this profile differentiates CLR 131iopofosine from many traditional on-market treatments and treatments in development. CLR 131Iopofosine is currently being evaluated in the CLOVER-WaM Phase 2 pivotal study in patients with r/r WM, a Phase 2B study in r/r multiple myeloma (MM)MM patients and the CLOVER-2 Phase 1 study for a variety of pediatric cancers. As with all clinical trials, adverse events, serious adverse events or fatalities may arise during a clinical trial due to medical problems that may not be related to clinical trial treatments. Adverse events across all studies include fatigue (39%) and cytopenias, specifically, thrombocytopenia (75%), anemia (61%), neutropenia (54%), leukopenia (56%), and lymphopenia (34%). Fatalities due to infection have occurred in patients treated with iopofosine.

CLR 131The CLOVER-WaM pivotal Phase 2B study is currently being evaluated in a pivotal study, CLOVER-WaM, inenrolling WM patients that have failed or had a suboptimal response to a BTKi therapy after receiving first line standard of care. The CLOVER-1 Phase 2 study met the primary efficacy endpoints from the Part A dose-finding portion, conducted in r/r B-cell malignancies, and is now enrolling aan MM expansion cohort (Phase 2B). The Phase 2B study will evaluate highly refractory MM patients including triple, quad and penta class refractory patients. The initial Investigational New Drug (IND) application was accepted by the FDA in March 2014 with multiple INDs submitted since that time. The Phase 1 study was designed to assess the compound’s safety and tolerability in patients with r/r MM, (toand to determine maximum tolerated dose (MTD), and was initiated in April 2015. The study completed enrollment and the final clinical study report is expected in the first half of 2021.2022. Initiated in March 2017, the primary goal of the Phase 2A study was to assess the compound’s efficacy in a broad range of hematologic cancers.

Table of Contents

The CLOVER-1 Phase 2 study met the primary efficacy endpoints from the Part A dose-finding portion, conducted in r/r B-cell malignancies. The CLOVER-1 Phase 2B study, where iopofosine remains under further evaluation in late treatment line highly refractory MM patients, is ongoing.

The CLOVER-2 Phase 1 pediatric study is being conducted internationally at seven leading pediatric cancer centers. The study is an open-label, sequential-group, dose-escalation study to evaluate the safety and tolerability of CLR 131iopofosine in children and adolescents with relapsed or refractory cancers, including malignant brain tumors, neuroblastoma, sarcomas, and lymphomas (including Hodgkin’s lymphoma). The FDA previously accepted our IND application for a Phase 1 open-label, dose escalating study to evaluate the safety and tolerability of a single intravenous administration of CLR 131iopofosine in up to 30 children and adolescents with cancers including neuroblastoma, sarcomas, lymphomas (including Hodgkin’s lymphoma) and malignant brain tumors. This study was initiated during the first quarter of 2019. These cancer types were selected for clinical, regulatory and commercial rationales, including the radiosensitive nature and continued unmet medical need in the r/r setting, and the rare disease determinations made by the FDA based upon the current definition within the Orphan Drug Act.

In December 2014, the FDA granted ODD for CLR 131iopofosine for the treatment of MM. In 2018, the FDA granted ODD and RPDD for CLR 131iopofosine for the treatment of neuroblastoma, rhabdomyosarcoma, Ewing’s sarcoma and osteosarcoma. In May 2019, the FDA granted Fast Track designation for CLR 131iopofosine for the treatment of MM and in July 2019 for the treatment of DLBCL, inDLBCL. In September 2019 CLR 131iopofosine received Orphan Drug DesignationODD from the European Union for Multiple Myeloma, in January 2020,MM. In December 2019, the FDA granted Orphan Drug Designation for CLR 131 WM and the European Union each granted Orphan Drug DesignationODD for CLR 131 iopofosine for the treatment of LPL/WM. The FDA granted Fast Track designation for CLR 131iopofosine for the treatment of r/r LPL and WM in May 2020.

As the result of CLR 131’siopofosine’s RPDD designation, Cellectarwe may be eligible to receive a priority review voucher (PRV) if the product receives approval for any of the treatment of neuroblastoma, rhabdomyosarcoma, Ewing’s sarcoma or osteosarcoma. The FDA may award (PRVs)PRV to sponsors of a product application for a RPDD that meet its specified criteria. The key criteria to receiving a priority review voucherPRV is that the drug be approved for a rare pediatric disease being treated isand treat a serious or life-threatening andmanifestation of the disease or condition that it primarily effectsaffects individuals under the age of 18. In order to receive a PRV, a sponsor must obtain approval of a “rare pediatric disease product application,” which is a human drug application for prevention or treatment of a rare pediatric disease and which contains no active ingredient, including any ester or salt thereof, that has been approved by the FDA; is deemed eligible for priority review; is submitted under section 505(b)(1) of the Federal Food, Drug, and Cosmetic Act (FDCA) or section 351(a) of the Public Health Service Act (PHSA); relies on clinical data derived from studies examining a pediatric population and dosages of the drug intended for that population; does not seek approval for an adult indication in the original rare pediatric disease application; and is approved after September 30, 2016. Under this program, a sponsor who receives an approval for a drug or biologic for a rare pediatric disease can receive a PRV that can be redeemed to receive a priority review of a subsequent marketing application for a different product. Additionally, the PRV’s can be exchanged or sold to other companies so that the receiving company may use the voucher. Congress has only authorized the rare pediatric disease priority review voucher program until September 30, 2024. However, if a drug candidate receives RPDD before September 30, 2024, it is eligible to receive a voucher if it is approved before September 30, 2026.

CLOVER-WaM: Phase 2 Study Pivotal Study in: Patients with r/r Waldenstrom’s Macroglobulinemia

In January 2021, we announced that a Type C guidance meeting with the FDA was conducted in September of 2020. The results of that guidance meeting provided Cellectar with an agreed upon path for conducting the CLOVER-WaM study; a single arm, pivotal study in WM patients that have received standard of care first line therapy and either failed or had a suboptimal response to BTKi therapy. We believe this design is in alignment with the feedback received from the FDA during the guidance meeting held in September 2020. The FDA agreed with the dose to be tested, our proposal for a safety and futility assessment to be conducted on the first 10 patients, the endpoint to be assessed, the statistical analysis plan and study size of 50 patients.patients, and requested that we submit a revised protocol. Based upon this agreement, a revised protocol was submitted and the pivotal study was initiated. WM is a rare, indolent and incurable form of non-Hodgkin’s lymphoma (NHL) that is composed of a patient population in need of new and better treatment options.

Table of Contents

The study is expected to enroll 50 WM patients who have received at least two prior lines of therapy, failed both lines of therapy including having failed or had a suboptimal response to a BTKi (i.e. ibrutinib). Patients in the trial will receive up to 4-doses of iopofosine over two cycles (cycle one days 1, 15, and cycle two days 57, 71) with each dose administered as a 15mCi/m² infusion. The primary endpoint of the trial is major response rate (MRR) as defined as a partial response (a minimum of a 50% reduction in IgM) or better in patients that receive a minimum total body dose (TBD) of 60 mCi with secondary endpoints of treatment free survival (treatment free remission), duration of response and progression free survival. An independent data monitoring committee (IDMC) will perform an interim safety and futility evaluation on the first 10 patients enrolled. If three of the 10 patients experience a Clinically Significant Toxicity (CST) then the dose will be reduced to 12.5 mCi/m². The assessment will occur patient by patient and will conclude after the tenth patient is evaluated; there is no planned study stoppage. The trial has been initiated at select US and international cancer centers and sites. In April 2022, we announced that an independent data monitoring committee (DMC) has completed its planned futility/efficacy assessment of the study and unanimously recommended continuation of the trial as planned.

CLOVER-1: Phase 2 Study in Select B-Cell Malignancies

The Phase 2 CLOVER-1 study is an open-label study designed to determine the efficacy and safety of CLR 131 in select B-cell malignancies (multiple myeloma (MM), indolent chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL), lymphoplasmacytic lymphoma (LPL)/Waldenstrom’s macroglobulinemia (WM), marginal zone lymphoma (MZL), mantle cell lymphoma (MCL), DLBCL, and central nervous system lymphoma (CNSL) who have been previously treated with standard therapy for their underlying malignancy. As of March 2022, the study arms for CLL/SLL, LPL/WM, MZL, MCL, and DLBCL are closed. Dosing of patients varied by disease state cohort and was measured in terms of TBD.

In July 2016, we were awarded a $2,000,000 National Cancer Institute (NCI) Fast-Track Small Business Innovation Research grant to further advance the clinical development of iopofosine. The funds supported the Phase 2 study initiated in March 2017 to define the clinical benefits of iopofosine in r/r MM and other niche hematologic malignancies with unmet clinical need. These niche hematologic malignancies include CLL, SLL, MZL, LPL/WM and DLBCL. The study is being conducted in approximately 10 U.S. cancer centers in patients with orphan-designated relapse or refractory hematologic cancers. The planned study enrollment was up to 80 patients.

The study’s primary endpoint is clinical benefit response (CBR), with secondary endpoints of overall response rate (ORR), progression free survival (PFS), time to next treatment (TtNT), median Overall Survival (mOS), duration of response (DOR) and other markers of efficacy following patients receiving one of three TBDs of iopofosine (<50mCi, ~50mCi and >60mCi), with the option for a second cycle approximately 75-180 days later. Dosages were provided either as a single bolus or fractionated (the assigned dose level split into two doses) given day 1 and day 15. Over the course of the study the dosing regimen of iopofosine advanced from a single bolus dose to two cycles of fractionated administrations of 15 mCi/m2 per dose on days 1, 15 (cycle 1), and days 57, 71 (cycle 2). Adverse events occurring in at least 25% of subjects were fatigue (39%) and cytopenias, specifically, thrombocytopenia (75%), anemia (61%), neutropenia (54%), leukopenia (51%), and lymphopenia (25%). Serious adverse events occurring in greater than 5% of subjects were restricted to thrombocytopenia (9%) and febrile neutropenia (7.5%).

Phase 2A Study: Patients with r/r Waldenstrom’s Macroglobulinemia Cohort

Patients in the r/r WM cohort all received TBD of ≥ 60 mCi (25 mCi/m² single bolus, 31.25 mCi/m² fractionated, 37.5 mCi/m² fractionated, or two cycles of mCi/m² fractionated) either as a bolus dose or fractionated. Current data from our Phase 2A2a CLOVER-1 clinical study show that sixa 100% ORR in 6 WM patients demonstrated 100% overall response rate (ORR) and an 83.3% major response rate with one patient achieving a complete response (CR), which continues at nearly 27 months post- last treatment. While median treatment free survival ((TRS)(TFS), also known as treatment free remission (TFR)), and duration of response (DOR) hasDOR have not been reached, the average treatment TFS/TFR is currently at 330 days. ThisWe believe this may represent an important improvement in the treatment of relapsed/refractoryr/r WM as we believe no approved or late-stage development treatments for second- and third-line patients have reported a CR to date. Based on study results to date, patients continue to tolerate iopofosine well, with the most common adverse events being cytopenias and fatigue.

Table of Contents

Phase 2A Study: Patients with r/r Multiple Myeloma Cohort

In September 2020, we announced that a 40% ORR was observed in the subset of refractory multiple myeloma patients deemed triple class refractory who received 60 mCi or greater total body dose (TBD).TBD. Triple class refractory is defined as patients that are refractory to immunomodulatory, proteasome inhibitors and anti-CD38 antibody drug classes. The 40% ORR (6/15 patients) represents triple class refractory patients enrolled in Part A of Cellectar’s CLOVER-1 study and additional patients enrolled in Part B from March through May 2020 and received >60mCi TBD.TBD (25 mCi/m2 single bolus, 31.25 mCi/m2 fractionated, 37.5 mCi/m2 fractionated, or two cycles of mCi/m2 fractionated) either as a bolus dose or fractionated. Patients with MM received 40 mg of dexamethasone concurrently beginning within 24 hours of the first CLR 131 infusion. All MM patients enrolled in the expansion cohort are required to be at least triple class refractory. The additional six patients enrolled in 2020 were heavily pre-treated with an average of nine prior multi-drug regimens. Three patients received a total body doseTBD of > 60 mCi and three received less than 60 mCi. Consistent with the data released in February 2020, patients receiving > 60 mCi typically exhibit greater responses. Based on study results to date, patients continue to tolerate CLR 131iopofosine well, with the most common and almost exclusive treatment emergenttreatment-emergent adverse events being cytopenias.are cytopenias, such as thrombocytopenia, neutropenia, and anemia.

Phase 2A: Patients with r/r non-Hodgkin’s lymphoma Cohort

In February 2020, we announced positive data from our Phase 2a CLOVER-1 study in patients with relapsed/refractory non-Hodgkin lymphoma (NHL)r/r NHL patients that were treated atwith three different doses (<50mCi, ~50mCi and >60mCi TBD. Patients in the r/r NHL cohort received TBD of either ≥ 60 mCi or < 60 mCi (25 mCi/m2 single bolus, 31.25 mCi/m2 fractionated, 37.5 mCi/m2 fractionated, or two cycles of mCi/m2 fractionated) either as a bolus dose or fractionated. Patients with r/r NHL who received <60mCi TBD and the >60mCi TBD had a 42% and 43% ORR, respectively and a combined rate of 42%. These patients were also heavily pre-treated, having a median of three prior lines of treatment (range, 1 to 9) with the majority of patients being refractory to rituximab and/or ibrutinib. The patients had a median age of 70 with a range of 51 to 86. All patients had bone marrow involvement with an average of 23%. In addition to these findings, subtype assessments were completed in the r/r B-cell NHL patients. Patients with DLBCL demonstrated a 30% ORR with one patient achieving a CR, which continues at nearly 24 months post-treatment. The ORR for chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL)CLL/SLL and marginal zone lymphoma (MZL) MZL patients was 33%.

Based upon the dose response observed in the Phase 2A study for patients receiving total body dosesTBDs of 60mCi or greater, we determined that patient dosing of CLR 131iopofosine in the pivotal study would be >60mCi TBD. Therefore, patients are now grouped as receiving <60mCi or >60mCi TBD.

The most frequently reported adverse events in all patients were cytopenias, which followed a predictable course and timeline. The frequency of adverse events havedid not increasedincrease as doses were increased and the profile of cytopenias remains consistent. Importantly, our assessment is that these cytopenias have had a predictable pattern to initiation, nadir and recovery and are treatable. The most common grade ≥3 events at the highest dose (75mCi TBD) were hematologic toxicities including thrombocytopenia (65%), neutropenia (41%), leukopenia (30%), anemia (24%) and lymphopenia (35%). No patients experienced cardiotoxicities, neurological toxicities, infusion site reactions, peripheral neuropathy, allergic reactions, cytokine release syndrome, keratopathy, renal toxicities, or changes in liver enzymes. The safety and tolerability profile in patients with r/r NHL was similar to r/r MM patients except for fewer cytopenias of any grade. Based upon CLR 131iopofosine being well tolerated across all dose groups, and the observed response rate, and especially in difficult to treat patients such as high risk and triple class refractory or penta-refractory, and corroborating data showing the potential to further improve upon current ORRs and durability of those responses, the study has been expanded to test a two-cycle dosing optimization regimen with a target total body dose TBD >60 mCi/m² of CLR 131.

In July 2016, we were awarded a $2,000,000 National Cancer Institute (NCI) Fast-Track Small Business Innovation Research grant to further advance the clinical development of CLR 131. The funds supported the Phase 2 study initiated in March 2017 to define the clinical benefits of CLR 131 in r/r MM and other niche hematologic malignancies with unmet clinical need. These niche hematologic malignancies include Chronic Lymphocytic Leukemia, Small Lymphocytic Lymphoma, Marginal Zone Lymphoma, Lymphoplasmacytic Lymphoma/WM and DLBCL. The study is being conducted in approximately 10 U.S. cancer centers in patients with orphan-designated relapse or refractory hematologic cancers. The study’s primary endpoint is clinical benefit response (CBR), with secondary endpoints of ORR, progression free survival (PFS,) median Overall Survival (mOS) and other markers of efficacy following patients receiving one of three TBDs of CLR 131 (<50mCi, ~50mCi and >60mCi), with the option for a second cycle approximately 75-180 days later. Dosages were provided either as a single bolus or fractionated (the assigned dose level split into two doses) given day 1 and day 15.

iopofosine.

In May 2020, we announced that the FDA granted Fast Track Designation for CLR 131iopofosine in WM in patients having received two prior treatment regimens or more.

Phase 1 Study in Patients with r/r Multiple Myeloma

In February 2020, we announced the successful completion of our Phase 1 dose escalation study. Data from the study demonstratedindicate that CLR 131iopofosine was safe and tolerated up to a total body doseTBD of approximately 95mCi in r/r MM. The Phase 1 multicenter, open-label, dose-escalation study was designed to evaluate the safety and tolerability of CLR 131iopofosine administered in an up to 30-minute I.V. infusion, either as a single bolus dose or as fractionated doses. The r/r multiple myelomaMM patients in this study received single cycle doses ranging from approximately 20mCi to 95mCi total body dose.TBD. An independent Data Monitoring Committee determined thatIDMC assessed the safety of all doses used were safewith patients and well-tolerated by patients.deemed them to be safe.

CLR 131Table of Contents

Iopofosine in combination with dexamethasone was under investigation in adult patients with r/r MM. Patients had to be refractory to or relapsed from at least one proteasome inhibitor and at least one immunomodulatory agent. The clinical study was a standard three-plus-three dose escalation safety study to determine the maximum tolerable dose. Multiple myeloma is an incurable cancer of the plasma cells and is the second most common form of hematologic cancers. Secondary objectives included the evaluation of therapeutic activity by assessing surrogate efficacy markers, which include M protein, free light chain (FLC), PFS and OS. All patients were heavily pretreated with an average of five prior lines of therapy. CLR 131 was deemed by an Independent Data Monitoring Committee (IDMC) to be safe and tolerable up to its planned maximum single, bolus dose of 31.25 mCi/m² or a total body dose of ~63 mCi. The four single dose cohorts examined were: 12.5 mCi/m² (~25mCi TBD), 18.75 mCi/m² (~37.5mCi TBD), 25 mCi/m²(~50mCi TBD), and 31.25 mCi/m²(~62.5mCi TBD), all in combination with low dose dexamethasone (40 mg weekly). Of the five patients in the first cohort, four achieved stable disease and one patient progressed at Day 15 after administration and was taken off the study. Of the five patients admitted to the second cohort, all five achieved stable disease however one patient progressed at Day 41 after administration and was taken off the study. Four patients were enrolled to the third cohort and all achieved stable disease. In September 2017, we announced results for cohort 4, showing that a single infusion up to 30-minutes of 31.25mCi/m² of CLR 131 was safe and tolerated by the three patients in the cohort. Additionally, all three patients experienced CBR with one patient achieving a partial response (PR). We use the International Myeloma Working Group (IMWG) definitions of response, which involve monitoring the surrogate markers of efficacy, M protein and FLC. The IMWG defines a PR as a greater than or equal to 50% decrease in FLC levels (for patients in whom M protein is unmeasurable) or 50% or greater decrease in M protein. Multiple myeloma is an incurable cancer of the plasma cells and is the second most common form of hematologic cancer. Secondary objectives included the evaluation of therapeutic activity by assessing surrogate efficacy markers, which include M protein, free light chain (FLC), PFS and OS. All patients were heavily pretreated with an average of five prior lines of therapy. An IDMC assessed the safety of iopofosine up to its planned maximum single, bolus dose of 31.25 mCi/m² or a TBD of ~63 mCi. The four single dose cohorts examined were: 12.5 mCi/m² (~25mCi TBD), 18.75 mCi/m² (~37.5mCi TBD), 25 mCi/m² (~50mCi TBD), and 31.25 mCi/m²(~62.5mCi TBD), all in combination with low dose dexamethasone (40 mg weekly). Of the five patients in the first cohort, four were assessed as achieving stable disease and one patient progressed at Day 15 after administration and was taken off the study. Of the five patients admitted to the second cohort, all five were assessed as achieving stable disease; however, one patient progressed at Day 41 after administration and was taken off the study. Four patients were enrolled to the third cohort, and all were assessed as achieving stable disease. In September 2017, we announced safety and tolerability data for cohort 4, in which patients were treated with a single infusion up to 30-minutes of 31.25mCi/m² of iopofosine, which was tolerated by the three patients in the cohort. Additionally, all three patients experienced CBR with one patient achieving a partial response (PR). The patient experiencing a PR had an 82% reduction in FLC. This patient did not produce M protein, had received seven prior lines of treatment including radiation, stem cell transplantation and multiple triple combination treatments including one with daratumumab that was not tolerated. One patient experiencing stable disease attained a 44% reduction in M protein. In January 2019, we announced that the pooled mOS data from the first four cohorts was 22.0 months. In late 2018, we modified this study to evaluate a fractionated dosing strategy to potentially increase efficacy and decrease adverse events.

Cohort 5 and cohort 6 werereceived fractionated cohortsdosing of 31.25 mCi/m²(~62.5mCi TBD) and 37.5 mCi/m²(~ (~75mCi TBD), each administered on day 1 and on day 8. Following the determination that all prior dosing cohorts were safe and tolerated, we initiated a cohort 7 utilizing a 40mCi/m2 (~95mCi TBD) fractionated dose administered 20mCi/m2 (~40mCi TBD) on days 1 and day 8. Cohort 7 was the highest pre-planned dose cohort and subjects have completed the evaluation period. The study completed enrollment and the final clinical study report is expected in the first half of 2021.

2022. Adverse events occurring in at least 25% of subjects were fatigue (26%) and cytopenias, specifically, thrombocytopenia (90%), anemia (65%), neutropenia (55%), leukopenia (61%), and lymphopenia (58%). Serious adverse events occurring in greater than 2 subjects were restricted to febrile neutropenia n=3 (9.7%).

In May 2019, we announced that the FDA granted Fast Track Designation for CLR 131iopofosine in fourth line or later r/r MM. CLR 131 is our small molecule radiotherapeutic PDC designed to deliver cytotoxic radiation directly and selectively to cancer cells and cancer stem cells. ItIopofosine is currently being evaluated in our ongoing CLOVER-1 Phase 2 clinical study in patients with relapsed or refractory multiple myelomar/r MM and other select B-cell lymphomas. Patients in the study received up to 4, approximately 20-minute IV infusions of iopofosine over 3 months, with doses given 14 days apart in each cycle and a maximum of 2 cycles. Low dose dexamethasone 40 mg weekly (20mg in patients ≥ 75), was provided for up to 12 weeks. The planned study enrollment was up to 80 patients. Its primary endpoint was clinical benefit rate (CBR), with additional endpoints of ORR, PFS, median overall survival (OS) and other markers of efficacy. Over the course of the study the dosing regimen of iopofosine advanced from a single bolus dose to two cycles of fractionated administrations of 15 mCi/m2 per dose on days 1, 15 (cycle 1), and days 57, 71 (cycle 2). Following treatment with iopofosine, approximately 91% of patients experience a reduction in tumor marker with approximately 73% experiencing greater than 37% reduction.

In December 2021, we presented data from 11 MM patients from our ongoing Phase 2 CLOVER-1 study in a poster at the American Society of Hematology (ASH) Annual Meeting and Exposition. The MM patients were at least triple class refractory (defined as refractory to an immunomodulatory agent, proteasome inhibitor and monoclonal antibody) with data current as of the end of May 2021. Patients had a median of greater than 7 prior therapies with 50% classified as high risk. Initial results in these patients showed an ORR of 45.5%, a CBR of 72.7% and a disease control rate (DCR) of 100%. Median PFS was 3.4 months. In a subset of 5 quad/penta drug refractory patients, efficacy increased, demonstrating an ORR of 80% and CBR of 100% in this highly treatment refractory group. The most commonly observed treatment emergent adverse events were cytopenias that included Grade 3 or 4 thrombocytopenia (62.5%), anemia (62.5%), neutropenia (62.5%) and decreased white blood cell count (50%). Treatment emergent adverse events were mostly limited to bone marrow suppression in line with prior observations. No patients experienced a treatment emergent adverse event of neuropathy, arrythmia, cardiovascular event, bleeding, ocular toxicities, renal function, alterations in liver enzymes, or infusion-site reactions or adverse events.

Table of Contents

CLOVER 2: Phase 1 Study in r/r Pediatric Patients with select Solid tumors, Lymphomas and Malignant Brain Tumors

In December 2017, the Division of Oncology at the FDA accepted our IND and study design for the Phase 1 study of CLR 131iopofosine in children and adolescents with select rare and orphan designated cancers. This study was initiated during the first quarter of 2019. In December 2017, we filedsubmitted an IND application for r/r pediatric patients with select solid tumors, lymphomas and malignant brain tumors. The Phase 1 clinical study of CLR 131iopofosine is an open-label, sequential-group, dose-escalation study evaluating the safety and tolerability of intravenous administration of CLR 131iopofosine in children and adolescents with cancers including neuroblastoma, sarcomas, lymphomas (including Hodgkin’s lymphoma)relapsed or refractory malignant solid tumors (neuroblastoma, Ewing’s sarcoma, osteosarcoma, rhabdomyosarcoma) and lymphoma or recurrent or refractory malignant brain tumors.tumors for which there are no standard treatments. Secondary objectives of the study are to identify the recommended efficacious dose of CLR 131iopofosine and to determine preliminary antitumor activity (treatment response) of CLR 131iopofosine in children and adolescents.

In August 2020, it was announced thatbased on data on four dose levels from 15mCi/m² up to 60mCi/m² were deemed safe and tolerable bym2, an independent Data Monitoring Committee andDMC permitted the beginning of the evaluation of the next higher dose cohort, at 75mCi/m² was initiated.m2. The IDMC advised, based upon the initial data, to enrich the 60 mCi/m2 dose level for patients over the age of 10 with HGG and Ewing sarcoma. Changes in various tumor parameters appeared to demonstrate initial response and tumor uptake. This includes patients with relapsed HGGs with over 5 months of PFS. In November 2020, we announced clinical data providing that CLR 131iopofosine had been measured in pediatric brain tumors, confirming that systemic administration of CLR 131iopofosine crosses the blood brain barrier and is delivered into tumors and that the data show disease control has been exhibited in heavily pretreated patients with ependymomas. In November 2021, we announced favorable data on changes in various tumor parameters in a Phase 1 study in children and adolescents with relapsed and refractory high-grade gliomas (HGGs) and soft tissue sarcomas. Pediatric HGGs are a collection of aggressive brain and central nervous system tumor subtypes (i.e. diffuse intrinsic pontine gliomas, glioblastomas, astrocytomas, ependymomas, etc.) with about 400 new pediatric cases diagnosed annually in the U.S.. Children with these tumors have a poor prognosis and limited 5-year survival. Adverse events occurring in at least 25% of subjects were fatigue, headache, nausea and vomiting (28% respectively), and cytopenias, specifically, thrombocytopenia (67%), anemia (67%), neutropenia (61%), leukopenia (56%), and lymphopenia (33%). There were no serious adverse events occurring in more than 2 subjects.

In 2018, the FDA granted ODD and RPDD for CLR 131iopofosine for the treatment of neuroblastoma, rhabdomyosarcoma, Ewing’s sarcoma and osteosarcoma. Should CLR 131If iopofosine should be approved for any of these pediatric indications, the first approved RPDD would enable us to receive a priority review voucher. Priority review vouchers can be used by the sponsor to receive priority review for a future New Drug Application (“NDA”)(NDA) or Biologic License Application (“BLA”)(BLA) submission, which would reduce the FDA review time from 12 months to six months. Currently, these vouchers can also be transferred or sold to another entity. In December 2020, the FDA extended the Priority Review Voucher Program through September 2026 for rare pediatric diseases.

Phase 1 Study in r/r Head and Neck Cancer

In August 2016, the University of Wisconsin Carbone Cancer Center (“UWCCC”)(UWCCC) was awarded a five-year Specialized Programs of Research Excellence (“SPORE”)(SPORE) grant of $12,000,000 from the National Cancer InstituteNCI and the National Institute of Dental and Craniofacial Research to improve treatments and outcomes for head and neck cancer HNC,(HNC) patients. HNC is the sixth most common cancer across the world with approximately 56,000 new patients diagnosed every year in the U.S. As a key component of this grant, the UWCCC researchers completed testing of CLR 131iopofosine in various animal HNC models and initiated the first human clinical study enrolling up to 30 patients combining CLR 131iopofosine and external beam radiation treatment (EBRT) with recurrent HNC in Q4the fourth quarter of 2019. This clinicalUWCCC has completed the part A portion of a safety and tolerability study was suspended becauseof iopofosine in combination with EBRT and preliminary data suggest safety and tolerability in relapsed or refractory HNC. The reduction in the amount or fractions (doses) of EBRT has the potential to diminish the (number and severity of) adverse events associated with EBRT. Patients with HNC typically receive approximately 60-70 Grays (Gy) of EBRT given as 2 – 3 Gy daily doses over a 6-week timeframe. Patients can experience long-term tumor control following re-irradiation in this setting; however, this approach can cause severe injury to normal tissue structures, significant adverse events and diminished quality of life. Part B of the COVID-19 pandemic overstudy will further assess the first three quarterssafety and potential benefits of 2020 but is now openiopofosine in combination with EBRT in a cohort of up to 24 patients. Adverse events occurring in at least 25% of subjects were fatigue (46%) and actively enrolling patients.cytopenias, specifically, thrombocytopenia (69%), anemia (77%), neutropenia (54%), leukopenia (69%), and lymphopenia (62%). There were no serious adverse events occurring in more than 2 subjects.

Table of Contents

Preclinical Pipeline

We believe our PDC platform has potential to provide targeted delivery of a diverse range of oncologic payloads, as exemplified by the product candidates listed below, that may result in improvements upon current standard of care (“SOC”)(SOC) for the treatment of a broad range of human cancers:

​

​

​

​

​

Results of Operations

Research and development expense. Research and development expense consist of costs incurred in identifying, developing and testing, and manufacturing product candidates, which primarily include salaries and related expenses for personnel, cost of manufacturing materials and contract manufacturing fees paid to contract manufacturers and contract research organizations, fees paid to medical institutions for clinical studies, and costs to secure intellectual property. The Company analyzes its research and development expenses based on four categories as follows: clinical project costs, preclinical project costs, manufacturing and related costs, and general research and development costs that are not allocated to the functional project costs, including personnel costs, facility costs, related overhead costs and patent costs.

Table of Contents

General and administrative expense. General and administrative expense consists primarily of salaries and other related costs for personnel in executive, finance and administrative functions. Other costs include insurance, costs for public company activities, investor relations, directors’ fees and professional fees for legal and accounting services.

Three Months Ended March 31, 20212022 and 20202021

Research and Development.Research and development expense for the three months ended March 31, 20212022 was approximately $4,633,000$3,887,000, compared to approximately $2,616,000$4,633,000 for the three months ended March 31, 2020.

2021.

The following table is ana summary comparison of approximate comparison summary of research and development costs for the three months ended March 31, 20212022 and March 31, 2020:2021:

​