Thanks, Rob, and good morning everyone. TAZVERIK continues to gain traction, and we're seeing encouraging prescription and awareness trends in epithelioid sarcoma, and we were pleased with the uptick we're seeing in follicular lymphoma given the challenges we faced with COVID. This morning, we'll go into greater detail on our progress in both indications. After a long career in Big Pharma, I decided to join the team here at Epizyme and I came here specifically because of the focus on the science of epigenetics as an interesting and promising way of addressing cancer. But more importantly, I came because I recognized that this specific medicine tazemetostat had the potential to help people with cancer in both solid and hematologic tumors. And now, as Epizyme's Chief Commercial Officer, it's a privilege to lead our efforts to bring TAZVERIK to patients. We've launched TAZVERIK as the first and only treatment specifically indicated for people who have epithelioid sarcoma, or ES, after receiving an accelerated approval from the FDA in January 2020. ES is an extremely rare disease affecting people primarily in their 30s and 40s. We estimate that there are approximately 800 people in the U.S. who have been diagnosed and are living with ES, of which 300 or so have metastatic disease and are eligible for TAZVERIK. We observed strong adoption in ES during the first half of 2020, driven by the significant medical need in this rapidly progressing cancer, along with the fact that we started introducing TAZVERIK traditionally roughly two months before we experienced the full effects of the COVID-19 pandemic. This provided us with the opportunity to initiate an in-person dialogue with our priority accounts before the environment shifted to the virtual world we have all become quite familiar with.
As we transition to the second half of the year, growth in ES began to plateau.
While we continue to see new patients starting therapy in the third and fourth quarters, some of the early patients treated in later lines of therapy began to cycle off treatment. Patients with multiple relapsed refractory disease have shown an average duration of therapy with TAZVERIK between four and five months consistent with our Phase II clinical data for second-line and later patients.
While we're seeing utilization of TAZVERIK across all lines of therapy in ES, the majority of initial usage has been in second and third-line or later patients due to the significant need for new treatment in the setting.
As physicians become more familiar with TAZVERIK and are reporting positive initial experiences, we expect that utilization will expand to earlier lines of therapy. Thanks to the ongoing education efforts of our team, awareness of TAZVERIK among physicians to treat ES has grown to over 80% as of Q4. This is exactly where we want to be in the months following approval. To wrap-up, ES, I want to emphasize that this year, we're continuing to focus on bringing this medicine to patients in the first line setting where our clinical data showed more favorable efficacy, providing the most benefit for these patients with limited treatment options.
As use of TAZVERIK in earlier lines of treatment expand, we expect duration of therapy will increase as well.
Now let's turn to our follicular lymphoma or FL progress since approval. Last June, we obtained a second FDA accelerated approval for TAZVERIK to treat adult patients with relapsed refractory FL. Unlike our launch in ES, the FL launch was completely virtual from the start, launching any oncology medicine during this pandemic has required overcoming a number of obstacles.
For our team, there have been two distinct challenges.
First, patients are visiting their doctors with less frequency, which is accentuated in FL compared with other cancers due to the indolent nature of the disease and the general age of the patient population.
While patient visits remain down compared to pre-COVID levels, during the first quarter, physicians and practices reported that they have recently started to encourage in-person visits again.
However, we continue to see a 20% to 30% reduction in new FL patient treatment starts on any therapy in the fourth quarter compared to pre-COVID level, which is understandable, as most physicians are reluctant to change therapies without seeing their patient's in-person. This obviously has had an impact on our ability to gain new patient starts for TAZVERIK following our approval, but we believe this will eventually improve with broader vaccination and given that many of these patients have been without a treatment change for some time now.
The second major hurdle has been our field teams' limited face-to-face access with treating physicians and their staff. To-date, our launch in FL has been almost entirely virtual.
While our teams have been able to reach all of their top tier accounts, frequency of access to physicians is challenging, and our ability to reach other accounts stakeholders have been less efficient in the virtual setting.
So here's the thing. It has taken more time to get traction with physicians than might otherwise be the case in person. And compounding this while our approved label allows for very broad use of TAZVERIK in patients with relapsed refractory FL, it can require some explanation given the two unique indication statements. To address these challenges, we have initiated a number of educational programs and non-personal promotion programs to support the team's efforts with physicians. We've adapted with novel tools for field interaction and focused on innovative peer-to-peer programming in multiple formats, such as virtual speaker events, local workshops, and medical education program. We've partnered with patient advocacy groups to support programs focusing on disease awareness that empower patients to be an active participant in their care.
We have also increased our digital presence by investing in a diverse mix of media, traditional online and social that are all focused on reaching healthcare professionals and patients.
As a result of our efforts, TAZVERIK use is coming from all lines of relapsed refractory therapy. The largest growth and share has been in the third-line and later patients where we exited December with the highest share of new patient starts with any individual treatment. But we also see growth in the second-line setting especially in patients with EZH2 mutations. We recorded our highest number of new prescribing accounts in the fourth quarter, which grew over 50% from the third quarter. In the context of the pandemic, we're pleased with this sequential growth.
While revenue grew 31% in the same period, TAZVERIK total bottle demand, including free goods grew 42%. Free goods were from our Patient Support Program EpizymeNOW, which provides TAZVERIK free of charge to eligible patients without the means to pay for therapy. We're committed to helping patients in need, and in December, it is common to see some increase in free goods, which was accentuated by the economic conditions created by the pandemic. Even with this December increase, the overall percentage of free goods was in line with our Annual Patient Assistance Program utilization assumption for 2020. Overall, we're pleased with the team's performance given the ongoing challenges presented by the COVID-19 pandemic. The ability to reach health care providers has been severely impacted for all companies. But our new field team of seasoned professionals has achieved the highest share of voice in person and virtually relative to others working in FL. TAZVERIK awareness has increased more than 60% since approval and physician intent to prescribe remains high, irrespective of patient's EZH2 mutation status.
Our teams continue to adjust their approach to reach prescribers and have shown remarkable tenacity and creativity. TAZVERIK prescriptions for FL are now being written for patients with EZH2 activating mutations, wild-type EZH2, as well as in untested patients. Utilization is continuing to grow in academic accounts, and more importantly, we're seeing large community prescribers expanding their adoption of TAZVERIK.
With the recent amendment of NCCN guidelines for relapsed refractory FL patients earlier this month that recommends TAZVERIK for patients with no satisfactory treatment options, and whose EZH2 status is unknown, we expect we'll continue to see increased TAZVERIK utilization and usage by physicians as they re-engage with their patients. What's more, payer coverage has continued to be very positive and reflective of our clinical data generated for TAZVERIK supporting broad use by physicians. Over 90% of insured lives in the U.S. are currently covered for TAZVERIK in both ES and FL indications. And the majority of prior authorization requirements are aligned to the patient population in our label.
While we expect some challenges to persist in 2021 due to the pandemic, we're focusing on what we can control: growing new accounts and prescribers, educating academic and community physicians about TAZVERIK, attractive safety and tolerability profile, continuing to identify appropriate patients who can benefit from TAZVERIK, and ensuring a positive physician experience.
Now I'll pass the call over to Paolo to talk about our financial results. I look forward to addressing your questions during Q&A. Paolo?