Merdad Parsey
Chief Medical Officer at Gilead Sciences
Thank you, Johanna. As always, I'll focus today on the most important updates and refer you to the appendix of the earnings presentation for a more comprehensive view of our pipeline programs. First, on slide 16, in HIV prevention. We've initiated the 5,000-plus participant Phase III purpose I trial setting lenacapavir for the prevention in adolescent girls and young women who are at risk of HIV infection. We're also in the initial stages of recruiting for purpose two to evaluate lenacapavir for prevention in over 3,000 cis-gender men, transgender and gender non-binary who have sex with men. We will provide updated time lines once enrollment is further along. In HIV treatment, the FDA granted priority review in August for lenacapavir for the treatment of people living with HIV who have developed multidrug resistance to other antiretrovirals. This is based on compelling CAPELLA data that demonstrated 81% of heavily treatment-experienced individuals achieved viral suppression when lenacapavir was combined with an optimized background regimen.
The PDUFA action date has been set for February 28, 2022, and if approved, lenacapavir would become the first available 6-month long-acting subcutaneous injection treatment for HIV. Earlier this week, we announced that enrollment had started for the Phase II trial for the long-acting oral combination of lenacapavir and islatravir. This is part of our collaborative work with Merck to develop more flexible options for people living with HIV with a once-weekly oral pill. Gilead is leading the development and clinical work for this oral combination and Merck is leading the clinical work for the injectable combination that is expected to enter Phase I clinical trials next year. Moving to Veklury on slide 17. We presented a late breaker at the IDWeek 2021 conference last month based on the Phase III PINETREE study, evaluating Veklury an outpatient intravenous COVID-19 treatment. The results demonstrated that a 3-day course of Veklury significantly reduced the risk of hospitalization for high-risk patients with COVID-19. In particular, Veklury demonstrated a statistically significant 87% reduction in risk for the composite primary endpoint of COVID-19-related hospitalizations or all-cause mortality by day 28 compared with placebo.
There were no deaths in either arm of the study by day 28. We stopped PINETREE enrollment at the halfway mark of 584 patients in April due to the COVID-19 landscape at the time, but the study remained blinded in collected outcome data in the enrolled patients. Upon analysis of those data, results were highly statistically significant and clinically meaningful, again, demonstrating the efficacy of Veklury. It also emphasizes the importance of early treatment with antiviral therapies. We have submitted these data to the FDA as an sNDA filing and are in discussions with other regulatory agencies to explore approval for IV Veklury in an outpatient setting. We're also continuing our work to develop novel oral antivirals for the treatment of COVID-19.
Moving to slide 18. We continue to view Trodelvy as a pipeline and a product. Trodelvy targets Trop-2, which is overexpressed in many solid tumor cells. So we believe that Trodelvy can have a meaningful impact on a wide range of cancers in addition to the second-line metastatic TNBC and second-line bladder indications that are approved today. We're all eagerly anticipating the readout from the Phase III TROPiCS-02 study, our randomized Phase III trial in HR-positive HER2-negative metastatic breast cancer. As a reminder, this is an event-driven trial, evaluating disease progression, and we have not yet achieved the target number of events. As such, we now expect to have the top line data readout in late January or early February. To be clear, data analysis will only begin once we achieve the required number of events. We remain confident for the potential of Trodelvy to deliver a clinically meaningful benefit to patients with HR-positive HER2-negative metastatic breast cancer.
We also continue to do advanced Trodelvy into registrational studies for other indications. For example, as recently posted on clinicaltrials.gov, we plan to initiate the Phase III trial in second to third line non-small cell lung cancer at risk and look forward to sharing updates for other solid tumors as we expand the program. As Dan mentioned, we'll also start to work with Merck on a new clinical study looking at Trodelvy in combination with Merck's KEYTRUDA for first-line metastatic TNBC and plan to initiate the trial in the first half of 2022. Moving on to slide 19. We continue to believe that with its synergistic potential and the safety profile observed to date, magrolimab could benefit patients with a variety of hematologic and solid tumors. As you know, our initial focus has been MDS and AML. While our commitment to these patients remains unchanged, we continue to evolve our clinical programs in the context of the recent developments in the MDS therapeutic landscape.
The ongoing Phase III ENHANCE trial evaluating magrolimab in higher-risk MDS is on track and enrolling well. We will discuss our development plans and regulatory path forward with the FDA before the end of the year. Meanwhile, the data from our Phase Ib trial continues to mature, and we now expect to share top line data in the first quarter of 2022. Looking beyond MDS, our ENHANCE II trial from magrolimab in first-line TP53 mutant AML is ongoing, targeting a new therapeutic option for nearly 2,000 patients in the U.S. In addition, an estimated 6,000 patients in the U.S. are diagnosed and treated annually with unfit AML. So we're expanding our development efforts to initiate a Phase III trial for first-line unfit AML by early next year. Over the past few months, we've initiated two solid tumor trials for magrolimab, one in head and neck cancer and a separate solid tumor basket study for patients with non-small cell lung cancer, small cell lung cancer and urothelial cancer.
We also plan to initiate a third study in metastatic TNBC. Based on broad CD47 expression, we're excited by magrolimab's potential to be an effective therapy for solid tumors and look forward to sharing more updates as they become available. Next, on behalf of Christi and the Kite team, I also wanted to highlight the most recent approval for Tecartus in adults with relapsed or refractory ALL on slide 20. There's an incredibly high unmet need for these patients with 50% of adult patients relapsing on currently available treatment. The approval was based on data from ZUMA-3, which demonstrated 65% of patients achieved complete remission. Additionally, as Johanna mentioned earlier, Kite has filed the sBLA for Yescarta in second-line LBCL. With a median follow-up of two years, the study met the primary endpoint of event-free survival with a hazard ratio of 0.398 and a p-value of less than 0.0001, representing a potential significant advance in the standard of care for LBCL patients.
We look forward to reviewing the entire data set at ASH and expect an update next year on approval status. Lastly, moving to slide 21. We remain very excited about our oncology partners, whose work spans many promising new pathways in oncology. For example, our partners at Arcus has a pipeline that includes not only anti-TIGIT candidates, but also CD73 and adenosine receptor inhibitors to promote immune responses and inhibit tumor growth. We continue to expect to trigger the opt-in review period for Arcus' Domvanalimab, likely later this year or early next year, pending the review of more mature data. Additionally, through our partnerships, we have access to several candidates that could help modulate immunosuppressive and tumor permissive cell types and pathways, including Tizona's HLAG checkpoint inhibitor, which recently expanded to a Phase Ib study; and Johnson's CCR inhibitor, which received IND clearance last quarter.
Other potential opt-in programs from partners include pioneers TREM1 and TREM2 antibodies, which are in Phase I trials in actively enrolling patients; and agenesis CD137 agonist, which is expected to be evaluated in the combination trial that will be initiated later this year. In closing, on slide 22, our teams are focused on executing across our oncology, virology and inflammation pipeline. And while it's still early days for our inflammation portfolio, remain committed and invested in continuing to advance our pipeline across various mechanisms of action, such as IRAK4, alpha four beta seven and TPL2. In combination with our opt-in partners, our pipeline portfolio spans many of the most promising targets across our three therapeutic focus areas. We're very excited and committed to build out our best-in-class and industry-leading franchises. I'll now hand it over to Andy.
