Phase III Results Could Boost Pfizer Revenue Ahead Of Xtandi’s Exclusivity Loss
Executive Summary
Pfizer and Astellas announced positive topline Phase III results in non-metastatic prostate cancer for Xtandi, one of the top-selling drugs in Pfizer’s portfolio set to lose patent exclusivity this decade.
Pfizer Inc. may be able to soften the blow of the impending loss of exclusivity for Xtandi (enzalutamide) by boosting revenue from the drug ahead of its patent expiration. That is because the company and its partner Astellas Pharma, Inc. reported topline Phase III results that may be able to broaden the scope of prostate cancer patients eligible for treatment.
Without disclosing full data, Pfizer and Astellas announced positive results on 16 March from the EMBARK trial of Xtandi in men with non-metastatic hormone-sensitive prostate cancer (nmHSPC), also known as non-metastatic castration-sensitive prostate cancer (nmCSPC) with high-risk biochemical recurrence. The readout offers an opportunity for Pfizer to grow its oncology portfolio revenue in addition to its $43bn purchase of Seagen Inc. announced earlier in the week.
The Phase III EMBARK trial comprised three arms: Xtandi monotherapy, Xtandi plus leuprolide and leuprolide with placebo. The trial met the primary endpoint of clinically meaningful improvement in metastasis-free survival (MFS) in the Xtandi/leuprolide arm. There was also a positive trend on the key secondary endpoint of overall survival (OS), but data were not mature.
Pfizer Moves To Head Off $17bn Revenue Loss
While not the top drug in Pfizer’s portfolio, Xtandi has been a significant revenue generator. In the fourth quarter of 2022, sales of the drug attributable to Pfizer were $320m, up 5% from the comparable period in 2021. For the full year of 2022, Pfizer took in Xtandi revenues of $1.2bn, up 1% from 2021. (Also see "From Hallelujah To Headwind: Pfizer's COVID-19 Franchise Hits The Downturn" - Scrip, 31 Jan, 2023.) Among Pfizer’s oncology portfolio, Xtandi was second to the breast cancer drug Ibrance (palbociclib), which had full-year sales of $5.1bn, down 6% from 2021, and will also lose exclusivity later in the decade.
Xtandi’s expected loss of exclusivity in 2027 has prompted Pfizer and Astellas to keep investing in additional prostate cancer indications to boost revenue from the drug ahead of the introduction of generics. Meanwhile, with both Xtandi and Ibrance generics on the horizon, Pfizer itself has gone hunting for portfolio and pipeline, with Seagen in particular able to add both commercial products and R&D assets in the area of oncology. (Also see "What Seagen’s Pipeline Will Bring To Pfizer" - Scrip, 16 Mar, 2023.)
Combining Xtandi, an anti-androgen drug, with PARP inhibitors in first-line metastatic castration-resistant prostate cancer (mCRPC) is a particularly competitive space in which Pfizer has sought to give Xtandi a new role.
In February, the company presented data at the American Society of Clinical Oncology Genitourinary Cancers Symposium (ASCO GU) for Xtandi combined with Pfizer’s in-house PARP inhibitor, Talzenna (talazoparib). In that setting, Xtandi/Talzenna would compete against Johnson & Johnson’s Zytiga (abiraterone acetate)/AstraZeneca PLC’s Lynparza (olaparib) and Zytiga/GSK plc’s Zejula (niraparib). (Also see "Can Lynparza Hold On As PARP Inhibitors Enter First-Line Prostate Cancer Market?" - Scrip, 16 Feb, 2023.) But while Pfizer hopes Talzenna can take on Lynparza in the PARP inhibitor space, it remains a small player in the New York-based drug maker’s overall portfolio and was not listed among top-selling oncology products in Pfizer’s 2022 earnings report.
But adding new indications for Xtandi will provide only a temporary reprieve for Pfizer. At its investor day in December, the company noted that it faces $17bn in lost revenue from losses of exclusivity between 2025-2030, with some of its top-selling drugs and biologics expected to face generic and biosimilar competition. (Also see "Pfizer Lays Out A Growth Plan To Offset $17bn In Coming Exclusivity Losses" - Scrip, 13 Dec, 2022.)
Faced with this impending loss of revenue, Pfizer made a big move to shore up its oncology business on 13 March when it plunked down $43bn in cash to acquire Bothell, WA-based Seagen. With Pfizer’s overall goal of adding $25bn in new revenue by 2030 through business development, the Seagen acquisition brought it within less than $5bn of hitting that mark, given that it has four products already approved and multiple candidates in its pipeline. It also adds to Pfizer’s R&D capabilities Seagen’s considerable presence in the antibody-drug conjugate (ADC) space, given that three of the biotech’s drugs are themselves ADCs. (Also see "Pfizer Pays $43bn For Seagen With Goal Of Rapidly, Globally Advancing ADCs" - Scrip, 13 Mar, 2023.)