ASCO 2026: New Data Highlight Advances in Prostate Cancer Treatments

New research presented at the 2026 ASCO Annual Meeting, held May 29 through June 2 in Chicago, showed that Nubeqa (darolutamide) was associated with potential cognitive benefits compared with Xtandi (enzalutamide), a finding that comes as the drug has already seen rapid uptake among Medicare beneficiaries in recent years, according to a CareSet analysis of Medicare Part D claims.

CareSet’s analysis showed significant growth in Nubeqa use over the past three years, from approximately 2,800 Medicare beneficiaries in January 2023 to more than 18,400 in March 2026. Total prescription fills jumped from 43,000 in 2023 to more than 169,400 in 2025, reaching over 55,600 in just the first three months of 2026. The prescriber base grew in parallel, from 1,461 unique prescribers in January 2023 to 5,925 by March 2026, a fourfold expansion.

The growth aligned with Nubeqa’s expanding label. The FDA first approved Nubeqa in July 2019 for nmCRPC. In 2022, the agency expanded the indication to include mCSPC when used in combination with docetaxel. In June 2025, the FDA approved it for mCSPC regardless of docetaxel use, broadening eligibility to patients who are not candidates for or do not receive chemotherapy.

Cognitive Outcomes Take Center Stage at ASCO

Nubeqa was associated with significantly less objectively assessed cognitive decline than Xtandi over 24 weeks, according to results from the randomized, head-to-head phase 2 ARACOG trial (AFT-47; NCT04335682) presented at ASCO.

At 24 weeks, patients treated with Nubeqa showed a median change in cognitive domain of -15.8%, compared to -36.1% observed with Xtandi, representing a statistically significant and clinically meaningful difference in cognitive decline. Notably, of the 23 patients who crossed over between treatment arms due to cognitive decline or adverse events, all moved from Xtandi to Nubeqa; none went the other direction.

The trial enrolled 111 patients with nonmetastatic castration-resistant prostate cancer (nmCRPC), metastatic castration-resistant prostate cancer (mCRPC), or metastatic castration sensitive prostate cancer (mCSPC) between August 17, 2021, and March 11, 2025. The median age of participants was 71 years, and 83% were white.

Nubeqa and Xtandi are among the second-generation androgen receptor inhibitors that have become mainstays in the treatment of advanced prostate cancer. Because androgen signaling plays an important role in brain function, therapies that suppress or block androgen activity have been associated with cognitive side effects in some patients. 

Still, despite Nubeqa’s momentum, Xtandi remained the largest branded androgen receptor inhibitor by patient count as of March 2026, and it carries broader FDA-approved indications than Nubeqa. In addition to mCSPC and castration-resistant prostate cancer, Xtandi is also approved for non-metastatic castration-sensitive prostate cancer with high-risk biochemical recurrence. 

CareSet’s analysis of Medicare Part D claims showed total Xtandi prescription fills doubled over the past three years, from 191,600 in 2023 to 375,000 in 2025, with patient and prescriber counts growing as well, though at a slower pace than Nubeqa’s expansion.

New Evidence Boosts Talzenna’s Outlook

While Lynparza (olaparib) remained the leading PARP inhibitor, Talzenna (talazoparib) was the fastest-growing entrant, rising from just 25 patient-months in 2023 to 5,263 in 2025 following its FDA approval in combination with Xtandi for HRR gene-mutated mCRPC. By March 2026, utilization was already on pace to surpass its full-year 2025 total, according to CareSet’s analysis.

That trajectory could accelerate further following results from the phase 3 TALAPRO-3 trial, presented at ASCO 2026 and simultaneously published in the New England Journal of Medicine. The study found that adding Talzenna to Xtandi reduced the risk of radiographic progression or death by 52% in patients with HRR gene-altered mCSPC, compared with Xtandi plus placebo, with an even greater benefit among patients with BRCA-mutated tumors.

Importantly, TALAPRO-3 moves PARP inhibition earlier in the treatment pathway. The Talzenna-Xtandi combination is already an established treatment option for HRR gene-mutated mCRPC based on the TALAPRO-2 trial. TALAPRO-3 now provides evidence supporting its use in the castration-sensitive setting, before resistance develops.

This strategy could “help address a critical gap in care by ensuring that more patients receive the benefits of PARP inhibition for mCSPC rather than relying on later lines of therapy that many patients may never reach,” said lead investigator Neeraj Agarwal, MD, FASCO, of the Huntsman Cancer Institute at the University of Utah Health. 

The opportunity comes with real-world challenges. At roughly $19,000 on average per prescription fill, Talzenna carried a higher average spending than Erleada (approximately $14,700), Lynparza (approximately $14,500), and Xtandi (approximately $13,600), according to CareSet’s analysis of Medicare claims between January 2023 and March 2026. 

HRR gene alterations occur in roughly one in four men with metastatic prostate cancer. Since Talzenna is indicated for patients with specific genetic mutations, its use depends on biomarker testing to identify eligible patients, which is not uniformly available across the Medicare population. While the TALAPRO-3 data strengthens the case for broader use, payer scrutiny and prior authorization requirements could affect the pace of uptake.