PFE Talzenna Combo Shows Strong Efficacy in Wider Prostate Cancer Use

Pfizer PFE reported positive top-line results from a late-stage study evaluating Talzenna (talazoparib), an oral PARP inhibitor, in combination with Xtandi (enzalutamide), an ARP inhibitor. The regimen was studied in patients with HRR gene-mutated metastatic castration-sensitive prostate cancer (mCSPC), also known as metastatic hormone-sensitive prostate cancer.

Talzenna was initially approved in the United States, the EU and several other regions as a monotherapy for adults with deleterious or suspected deleterious gBRCAm HER2-negative locally advanced or metastatic breast cancer. Later, Talzenna in combination with Xtandi received FDA approval for treating adult patients with HRR gene-mutated metastatic castration-resistant prostate cancer (mCRPC). The regimen is also approved in the EU for adults with mCRPC in whom chemotherapy is not clinically indicated. The combo is currently authorized in around 60 countries, with indications varying by region. However, for HRR gene-mutated mCSPC, Talzenna/Xtandi is currently an investigational treatment regimen.

Pfizer’s phase III TALAPRO-3 study enrolled 599 patients with mCSPC, who had received at most three months of androgen deprivation therapy (chemical or surgical), with or without an approved ARP inhibitor in this setting. Eligible patients in the study were randomized to receive Talzenna 0.5 mg/day plus Xtandi 160 mg/day, or placebo plus Xtandi 160 mg/day.

In the past six months, PFE shares have gained 14% against the industry’s decline of 13%.

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PFE’s Late-Stage Prostate Cancer Study Results in Detail

Pfizer reported that its phase III TALAPRO-3 study met the primary endpoint, with Talzenna in combination with Xtandi delivering a statistically significant and clinically meaningful improvement in radiographic progression-free survival compared to placebo plus Xtandi. The results substantially surpassed the pre-specified hazard ratio target of 0.63, with most patients remaining progression-free at the time of analysis. The benefit was consistent across subgroups, including in patients whose tumors harbored BRCA and non-BRCA HRR gene alterations.

At the interim analysis, Pfizer also observed a strong trend toward improved overall survival, a key secondary endpoint. Additional benefits were seen across other secondary endpoints, including overall response rate, duration of response, and time to prostate-specific antigen progression. The safety profile of the combination was in line with the known profiles of the individual drugs, with no new safety signals reported.

Pfizer noted that existing treatment options often leave patients with HRR gene-mutated mCSPC vulnerable to early disease progression. The TALAPRO-3 study findings suggest that earlier use of Talzenna in combination with Xtandi can significantly delay disease worsening, highlighting the potential benefit of introducing this regimen sooner in the treatment course.

Prostate cancer remains the second most common cancer among men globally, with around 330,000 new cases expected in the United States in 2026. Despite recent advances, nearly 50-65% of mCSPC patients progress to mCRPC within two years, with a higher risk among those harboring HRR gene mutations — present in about 25% of metastatic cases — who typically face poorer outcomes and limited responsiveness to standard therapies, underscoring a significant unmet need.

Pfizer is currently gearing up to submit the phase III TALAPRO-3 study results of the Talzenna/Xtandi combo in mCSPC for presentation at an upcoming medical conference and plans to engage with global health authorities soon to discuss potential regulatory filings.

Pfizer Inc. Price and Consensus

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PFE’s Zacks Rank & Stocks to Consider

Pfizer currently carries a Zacks Rank #3 (Hold).

Some better-ranked stocks in the biotech sector are Catalyst Pharmaceuticals CPRX, ADMA Biologics ADMA and Inovio Pharmaceuticals INO. While CPRX sports a Zacks Rank #1 (Strong Buy), ADMA and INO carry a Zacks Rank #2 (Buy) each at present. You can see the complete list of today’s Zacks #1 Rank stocks here.

Over the past 60 days, estimates for Catalyst Pharmaceuticals’ 2026 EPS have risen from $2.55 to $2.82. CPRX shares have gained 11.3% over the past six months.

Catalyst Pharmaceuticals’ earnings beat estimates in each of the trailing four quarters, with the average surprise being 35.19%.

Over the past 60 days, estimates for ADMA Biologics’ 2026 earnings per share (EPS) have increased from 85 cents to 96 cents. ADMA shares have lost 6.3% over the past six months.

ADMA Biologics’ earnings beat estimates in one of the trailing three quarters, matched once and missed on the remaining occasion, with the average negative surprise being 1.79%.

Over the past 60 days, estimates for Inovio Pharmaceuticals’ 2026 loss per share have narrowed from $1.26 to $1.12. INO shares have plunged 33.8% over the past six months.

Inovio Pharmaceuticals’ earnings beat estimates in each of the trailing four quarters, with the average surprise being 57.94%.

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