Kyntra Bio Inc. (NASDAQ:KYNB), formerly Fibrogen, shares fluctuated in Tuesday’s premarket session as the company announced data from a Phase 1b/2 study of FG-3246 in combination with enzalutamide for treating metastatic castration-resistant prostate cancer.



Astellas Pharma Inc. (OTC:ALPMF) (OTC:ALPMY) and Pfizer Inc. (NYSE:PFE) are jointly commercializing enzalutamide under the Xtandi brand name.



<h2>Prostate Cancer Data Shows Response Rate Of 21%</h2>



The data presented showed a median radiographic progression-free survival (rPFS) of 10.1 months in patients who had progressed on only one prior androgen receptor pathway inhibitor (ARPI).



The study included 44 patients, with a composite response rate of 21% in the overall cohort and 40% in patients who had progressed on only one prior ARPI.



In addition, the study highlighted a trend suggesting that higher tumor uptake of FG-3180 was associated with a greater probability of achieving a PSA50 response. The results were presented at the 2026 American Society of Clinical Oncology Genitourinary Cancers Symposium.



Median rPFS of 7.0 months was observed in the overall cohort.



Combination therapy of FG-3246 and enzalutamide demonstrated a similar safety profile as was observed in the previous Phase 1 monotherapy trial of FG-3246. Neutropenia risk was mitigated with the use of G-CSF prophylaxis.



FG-3246 is currently being evaluated in a Phase 2 monotherapy trial with interim data expected in the second half of 2026.



<h2>Analyst View</h2>



William Blair on Tuesday wrote, “While acknowledging all the limitations and caveats associated with cross-trial comparison, we believe the FG-3246 combination results are provocative and provide validation heading into the Phase II monotherapy trial interim analysis, slated to occur in the second half.”



“We also emphasize that the administration of prophylactic growth factor appears to reduce dose-limiting neutropenia, which should also bode well for the monotherapy study,” analyst Andy Hsieh further added.



Overall, William Blair says they are encouraged by initial results generated from the FG-3246 program.



Given the early stage of FG-3246, along with the highly competitive prostate cancer market, analyst Hsieh says it is prudent to wait for additional data. William Blair reiterates a Market Perform rating on Kyntra shares.



KYNB Price Action: Kyntra Bio shares were up 0.75% at $8.110 during premarket trading on Tuesday, according to Benzinga Pro data.



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SBIO

Kyntra Bio Inc. (NASDAQ:KYNB) announced positive data from a Phase 1b/2 study of FG-3246 combined with enzalutamide for metastatic castration-resistant prostate cancer. The study showed a median radiographic progression-free survival of 10.1 months and a composite response rate of 21%. Analysts from William Blair expressed encouragement over the results but advised caution due to the competitive market. Kyntra shares rose 0.75% to $8.110 in premarket trading.

What's Going On With Kyntra Bio Stock Tuesday?