Pfizer expects that the FDA’s approval of Talzenna, a PARP inhibitor, for castration-resistant prostate cancer (CRPC) would enable it to compete with Lynparza, the market leader from AstraZeneca and Merck & Co.
In addition to Pfizer’s well-known hormonal medication Xtandi (enzalutamide), the FDA has approved Talzenna (talazoparib) for the treatment of people with metastatic homologous recombination repair (HRR) gene-mutated CRPC.
Olaparib, the active ingredient in Lynparza, has been licensed for use in these patients since 2020, but Talzenna, according to Pfizer, is the first medicine in the PARP class to be approved in conjunction with Xtandi, a first-line treatment.
The TALAPRO-2 study, which compared Talzenna to a placebo added to Xtandi, led to the approval because it showed a 37% increase in radiographic progression-free survival (rPFS) and a 55% decrease in the probability of either disease progression or death in the PARP inhibitor group.
According to Pfizer, the new indication would enable Talzenna, which has so far trailed Lynparza on the market, to generate $1 billion in yearly revenues. Sales of the medicine do not necessitate a distinct line in its financial reporting, despite the fact that AZ and Merck’s drug generated roughly $4 billion in revenue last year.
Until recently, Lynparza’s label included ovarian, breast, prostate, and pancreatic cancers, and the latest approval provides it a chance to gain some distance on Talzenna, which was only authorized for BRCA-mutated, HER2-negative metastatic breast cancer.
Related: Talazoparib Plus Enzalutamide for HRR Gene-Altered mCRPC Receives FDA Approval
Despite this, the drug developed by AZ and Merck continues to outperform its competitors thanks to approvals for a larger, all-inclusive population with metastatic CRPC based on preliminary findings from the PROpel trial, which combined the PARP drug with Johnson & Johnson’s hormonal therapy Zytiga (abiraterone acetate), Xtandi’s main market rival.
While this is going on, J&J is also aiming for first-line advanced CRPC. Akeega, a combination of its PARP medication niraparib and abiraterone acetate, recently received EU clearance for use in mCRPC patients with BRCA mutations. The MAGNITUDE trial, which demonstrated a 45% improvement in rPFS versus Zytiga and a tendency towards increased overall survival, served as the foundation for that approval.
“Despite treatment advancement in metastatic castration-resistant prostate cancer, the disease can progress quickly, and many patients may only receive one line of therapy. Therefore, new first-line treatment options are needed to reduce the risk of disease progression or death.”
– Neeraj Agarwal of the University of Utah, who was the lead investigator on TALAPRO-2
Pfizer is currently conducting the TALAPRO-3 trial, set to conclude next year, which involves the combination of Talzenna and Xtandi for the treatment of metastatic castration-sensitive prostate cancer (CSPC) in patients with homologous recombination repair (HRR) deficiency. These two drugs were acquired by Pfizer in 2016 as part of its $14 billion acquisition of Medivation.
The TALAPRO-3 trial aims to assess the efficacy and safety of combining Talzenna and Xtandi in this specific patient population. The results of the TALAPRO-3 trial, expected to be available next year, will provide valuable insights into the efficacy and potential benefits of this combination therapy in the targeted patient population. This research underscores Pfizer’s ongoing commitment to exploring innovative treatment approaches for prostate cancer, utilizing the medications it acquired through the Medivation acquisition.
