Kyntra Bio Announces Positive Data from Prostate Cancer Drug Trial

FG-3246 combination therapy shows promising results in metastatic castration-resistant prostate cancer patients

Published on Feb. 23, 2026

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Kyntra Bio, formerly FibroGen, announced positive data from an investigator-sponsored Phase 1b/2 study evaluating the anti-tumor activity of their drug candidate FG-3246 in combination with enzalutamide in patients with metastatic castration-resistant prostate cancer (mCRPC). The results, which will be presented at the 2026 ASCO GU Symposium, showed a median radiographic progression-free survival (rPFS) of 7.0 months in the overall study cohort, with a notable 10.1 months of median rPFS observed in patients who had progressed on only one prior androgen receptor pathway inhibitor (ARPI) therapy.

Why it matters

The positive data, particularly the improved outcomes in patients with only one prior ARPI treatment, suggests FG-3246 may be an effective therapy for earlier lines of mCRPC. Additionally, the potential of the companion diagnostic FG-3180 to serve as a biomarker for patient selection is an intriguing finding that could help identify those most likely to benefit from FG-3246 treatment.

The details

The Phase 1b/2 study enrolled 44 biomarker unselected mCRPC patients, with over 60% having progressed on two or more prior ARPI therapies. The combination of FG-3246 and enzalutamide demonstrated a composite response rate of 21% in the overall cohort, and 40% in patients who had progressed on only one prior ARPI. The safety profile was similar to the previous FG-3246 monotherapy trial, with neutropenia risk mitigated through use of G-CSF prophylaxis. Notably, higher tumor uptake of the companion diagnostic FG-3180 showed a trend towards higher probability of PSA50 response.

  • The data will be presented at the 2026 ASCO GU Symposium, taking place February 26-28, 2026 in San Francisco.
  • Kyntra Bio's FG-3246 Phase 2 monotherapy trial is on track for an interim analysis in the second half of 2026.

The players

Kyntra Bio

A biopharmaceutical company focused on developing novel therapies in oncology and rare disease, including FG-3246 for metastatic castration-resistant prostate cancer.

Dr. Rahul Aggarwal

Professor of Medicine at the University of California San Francisco and Principal Investigator of the FG-3246 combination study.

Thane Wettig

Chief Executive Officer of Kyntra Bio.

FG-3246

A potential first-in-class fully human antibody-drug conjugate (ADC) targeting CD46, which is being developed by Kyntra Bio for metastatic castration-resistant prostate cancer and potentially other tumor types.

FG-3180

A companion diagnostic PET imaging agent using the same CD46-targeting antibody as FG-3246, which is being evaluated for its potential to inform patient selection.

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What they’re saying

“The results from this Phase 1b/2 investigator-initiated study demonstrate encouraging preliminary anti-tumor activity of FG-3246 in combination with enzalutamide in patients with mCRPC. Notably, the 10.1 months of rPFS in patients with only one prior ARPI underscores the potential of FG-3246 in earlier lines of therapy.”

— Dr. Rahul Aggarwal, Professor of Medicine at the University of California San Francisco, and Principal Investigator of the study

“These data from the investigator sponsored trial expand on the clinically meaningful results previously observed with FG-3246. The 10.1 months of median rPFS observed in patients progressing on only one prior ARPI, and the mitigation of neutropenia related adverse events with prophylactic G-CSF are especially encouraging as they further validate our Phase 2 monotherapy trial design.”

— Thane Wettig, Chief Executive Officer of Kyntra Bio

What’s next

Kyntra Bio's FG-3246 Phase 2 monotherapy trial is on track for an interim analysis in the second half of 2026.

The takeaway

The positive results from the FG-3246 combination therapy trial, particularly the improved outcomes in earlier-line mCRPC patients, suggest this novel antibody-drug conjugate could be an effective treatment option. The potential of the companion diagnostic FG-3180 to serve as a biomarker for patient selection is also an intriguing finding that warrants further exploration.