Thank you, Brett. In February, we provided guidance for this year that reflects our new strategy to maximize the value of our wholly-owned medicines focused primarily on commercializing our rare neurological and cardio metabolic disease programs.
Our first quarter results of $112 million in revenue, $159 million in non-GAAP operating expenses, and a non-GAAP net loss of $45 million reflected this new strategy and were in line with our expectations.
Now turn to our revenues. SPINRAZA generated over $521 million in global sales. We earned $60 million in royalty revenue as a result, and virtually all of that revenue falls to our bottom line as profit.
Our first quarter SPINRAZA revenue decreased slightly compared to the prior quarter. Because our royalty rate resets at the beginning of each year.
As in prior years, we expect to reach the highest royalty tier by mid-year. The respond into those studies continue to progress well, these studies remain important elements of Biogen's ongoing efforts to enhance estimate patient outcomes and guide treatment decisions. We look forward to additional steps Biogen plans to take to further reinforce SPINRAZAs proven efficacy and safety profile SMA patients of all ages. SPINRAZA remains the SMA market leader and with over 11,000 patients on treatment and over 60,000 SMA patients, in markets where Biogen has a commercial presence. We believe SPINRAZA will continue to be a foundation of care for the treatment with SMA.
We also generated combined TEGSEDI and WAYLIVRA revenue of $20 million.
As a reminder, our guidance reflects a shift in revenue for TEGSEDI and WAYLIVRA due to the change in [technical difficulty] under our Sobi.
We are pleased with the smooth transition of our TEGSEDI and WAYLIVRA operations to Sobi, which are now complete in Europe and well underway for TEGSEDI in North America. Under our new distribution model, our commercial revenues from these products shift from product sales to distribution fees based on Sobi's net sales. In the first quarter, our revenues reflected this shift in Europe. Beginning in the second quarter, revenue with TEGSEDI sales in North America will also reflect this shift.
In addition, we earned nearly $30 million of R&D revenues in the first quarter, which we generated from multiple sources related to our partner programs.
Our non-GAAP operating expenses were $159 million in the first quarter, which represented a modest increase compared to the same period last year, and was in line with our guidance. The increase was driven by higher R&D expense, related primarily to advancing the Phase 3 studies of TTR LICA and APOCIII LICA and development activities for multiple programs across our wholly-owned pipeline.
As expected, our SG&A expenses decreased in the first quarter, primarily due to cost efficiencies we realized from the integration of Akcea and the restructuring of our European operations. An important element of our new strategy is our focus on investing internally for growth. And our first quarter results [technical difficulty] this aspect of our strategy. With our first quarter results, we remain on track to achieve our 2021 guidance, of a net loss of less than $75 million on a non-GAAP basis.
We expect our revenues in Q2 to be similar to the first quarter. And we're projecting an increase in revenue in the second half of this year, driven impart by increasing R&D revenues as we achieve key milestone for our partner programs. Already in the second quarter, we achieved a $10 million, Biogen for advancing ION54, our medicine targeting DGAT2 for the treatment of ALS. We project operating expenses to increase over the course of this year as our mid and late stage medicines advanced in development.
We expect our R&D expenses to increase as the Phase 3 studies of TTR LICA and APOCIII LICA progress as we initiate the APOCIII LICA Phase 3 study for patients with severely high triglycerides. And as DGAT2 advance PKKL into a Phase 3 study.
We expect our SG&A expenses to decrease further in the second half of this year, as we realize savings from our Sobi transaction. Last month using their balance sheet when we completed a $630 million convertible notes offering. These notes carry a 0% interest rate. We completed this transaction to accomplish two primary goals. To refinance the $310 million of 1% convertible notes due in November. And second to fund a large capital projects we recently initiated. We evaluated multiple financing options to achieve our goals and ultimately, with a 0% interest rate, we determined that the low cost of capital we secured through the convertible debt offering was our best financing option.
Importantly, we maintain a strong balance sheet to support our wholly-owned pipeline and our technology. We use a portion of the proceeds from our debt offering for a large capital project to expand our manufacturing and R&D capacity.
We expect this multiyear project to cost between $250 million and $350 million. We anticipate complete the project in 2024 and once complete, we will have the manufacturing capacity to support the future needs of our wholly-owned pipeline.
Additionally, we will increase our capacity to bring forward novel chemistries, including new LICA chemistry.
Continued critical [technical difficulty] we advance our wholly-owned pipeline to the market. This project enables us to build on our leadership and development, chemistry and manufacturing of oligonucleotide therapeutics. And to ensure we have the infrastructure we need to achieve our strategic objectives.
As you can see, we have taken important steps already this year to drive growth and to position us to achieve our goal of 12 or more marketed products in 2026. And with that, I'll turn the call over to Richard.