The US Food and Drug Administration on October 26, 2026 expanded the approval of Pfizer’s Talzenna (talazoparib) taken together with Xtandi (enzalutamide) to men with an earlier stage of spread prostate cancer whose tumors carry flaws in DNA-repair genes1. Until now, the pairing was approved in the US only for cancer that had stopped responding to hormone therapy2. The new approval covers men whose cancer has spread beyond the prostate but still responds to hormone-lowering treatment2.
What the FDA approved
Talzenna belongs to a group of drugs called PARP inhibitors, which target the way cancer cells repair damaged DNA2. Xtandi blocks the male hormone signals that many prostate cancers use to grow; it is sold by Pfizer and Astellas2. The two pills are given alongside standard hormone-lowering treatment, known as androgen deprivation therapy1.
The approval applies only to men whose tumors have flaws in homologous recombination repair (HRR) genes, one of the systems cells use to fix broken DNA1. The label spans 12 genes rather than only the two best-known ones, BRCA1 and BRCA21. The flaw must be found by an FDA-authorized test2. Two FoundationOne tests, one using tumor tissue and one using a blood sample, are authorized for this1.
The FDA gave the application priority review and handled it under Project Orbis, a program in which cancer drug reviews run at the same time with regulators in other countries1. The European Medicines Agency is reviewing a parallel application2.
The evidence: one large trial
The decision rests on a trial called TALAPRO-3, a Phase 3 study (the last large test before approval) sponsored by Pfizer3. It started in May 20213. It enrolled 599 men and randomly split them evenly between Talzenna or a placebo (a dummy pill), each taken with Xtandi and continued hormone-lowering treatment2. It was double-blind, meaning neither the men nor their doctors knew who got which pill2.
To join, men needed a flaw in at least one of 12 DNA-repair genes, among them BRCA1, BRCA2, ATM, CDK12 and PALB2, found by sequencing tumor tissue or tumor DNA in the blood2.
The main goal was how long men lived without their cancer visibly growing on scans, as judged by the trial doctors1. On that measure, adding Talzenna lowered the risk of scan-confirmed growth or death by 52%1. In technical terms the hazard ratio was 0.48, which means that at any point in the study, men on the combination had roughly half the risk of those on the dummy pill2.
- Men on the dummy pill plus Xtandi went a median of 45.8 months before their cancer grew on scans or they died; the median for the Talzenna group had not yet been reached2.
- At three years, 77% of men on the combination were alive without scan-confirmed growth, compared with 56% of men on the dummy pill2.
- The benefit was reported as consistent in men with BRCA flaws and men with flaws in other repair genes1.
The results were presented at the American Society of Clinical Oncology 2026 Annual Meeting and published at the same time in the New England Journal of Medicine2.
What it does not show yet
The biggest open question is whether the combination helps men live longer. Overall survival was the trial’s key secondary goal2, but those data were not mature when the main analysis was done1. At an early look, 78% of men on Talzenna and 72% on the dummy pill were alive at three years, a difference that did not meet the trial’s preset bar for statistical significance2. Pfizer’s own risk disclosures list whether the trial will meet its survival goal as an uncertainty1.
There are other limits. Because the Talzenna group has not reached its median, the real gap in time between the two groups is not yet defined1. The 45.8-month figure in the comparison group also shows that Xtandi alone kept the disease in check for a long time in these men1. And the main result relied on the trial doctors’ own reading of scans, which can differ from review by independent experts who do not know which treatment each man received1.
Side effects
Serious side effects were more common with the added drug. Severe or worse side effects affected 81% of men on Talzenna and 44% on the dummy pill, and serious side effects affected 42% and 32%2. The most common severe problem was anemia, a shortage of red blood cells, seen in 51% of the Talzenna group versus 3% of the comparison group; 5% of men stopped Talzenna because of it1. In pooled data, 41% of men treated with the combination needed a red blood cell transfusion2. The trial recorded 2 deaths linked to treatment, both in the Talzenna group2.
Pfizer said the safety findings matched what was already known for each drug, with no new signals2. The prescribing information warns about harm to a developing fetus, low blood counts, and rare blood cancers called myelodysplastic syndrome and acute myeloid leukemia, and it calls for monthly blood count checks during treatment2.
Who is behind it
Pfizer sponsored TALAPRO-33 and announced the approval1. The trial’s global lead investigator and first author of the published study is Neeraj Agarwal2. In Pfizer’s announcement, he said:
This approval represents a critical advancement for patients with newly diagnosed metastatic prostate cancer with HRR gene mutations, who face a more aggressive disease, worse prognosis, and limited treatment options.
Agarwal’s comments appeared in the company’s news release2. Pfizer executive Aamir Malik said the move offers “a new option at a stage where it may have a greater impact to delay progression”1. Those are hopes about the earlier stage; the trial itself has so far shown a delay in scan-confirmed growth, not a survival benefit.
How it fits the field
Talzenna was first approved on its own for certain breast cancers linked to inherited BRCA flaws1. The FDA cleared the Talzenna-Xtandi pairing in June 2023 for prostate cancer with DNA-repair flaws that no longer responded to hormone therapy, and the European Commission followed in January 2024 for a similar group1. That earlier approval rested on a trial called TALAPRO-2, in which the combination lowered the risk of growth or death by 55% in men with these gene flaws2. Pfizer says the combination is approved in more than 60 countries, with uses varying by country1.
Pfizer estimates about 25% of men with this earlier, hormone-responsive form of spread prostate cancer have DNA-repair gene flaws1. Because a positive test is required, how many men end up getting the combination will depend partly on how often doctors order gene testing at diagnosis1.
What to watch next
- Survival data. Later analyses of TALAPRO-3 will show whether the combination helps men live longer, which is still uncertain1.
- Europe. The European Medicines Agency’s review of a parallel application is ongoing2.
- Full results on the registry. The trial record lists the study as active but no longer recruiting, with results not yet posted there3.
