Foresee Pharmaceuticals has announced the submission of a New Drug Application (NDA) to the U.S. Food and Drug Administration (FDA) for its ready-to-use, 3-month depot formulation of leuprolide mesylate (Camcevi) for the palliative treatment of patients with advanced prostate cancer. This submission aims to provide an alternative treatment option for patients requiring androgen ablation therapy. The potential approval and launch are anticipated in 2025 and 2026, respectively.
Phase 3 Trial Data
The NDA is backed by data from an open-label, single-arm phase 3 trial (NCT03261999) that evaluated the efficacy and safety of leuprolide mesylate. The trial demonstrated a 97.9% (95% CI, 93.5%-99.3%) suppression rate of serum testosterone to levels no greater than 50 ng/dL by day 28 and maintained from days 28 to 168 in the intention-to-treat population (n = 144). At day 28, the mean testosterone concentration was 17.8 ng/dL, with a suppression rate of 98.6% among evaluable patients (n = 143). No mean increase in testosterone levels was observed following the second injection. Of the three patients who did not meet the primary endpoint, two failed to achieve the required castration level on day 28, and one experienced a transient testosterone escape after the second injection.
Safety Profile
The safety analysis revealed that 90 patients experienced a total of 217 treatment-emergent adverse events (TEAEs). The majority of these were grade 1 (165 TEAEs in 79 patients) or grade 2 (43 TEAEs in 28 patients). Nine severe TEAEs were reported in seven patients. The most common adverse events, occurring in more than 5% of patients, included hot flushing (24.31%), hypertension (11.11%), increased body weight (7.64%), and injection site hemorrhage (5.56%).
Current Landscape and Future Implications
Leuprolide mesylate is an established treatment for advanced prostate cancer, with a 6-month subcutaneous depot formulation already approved by the FDA in May 2021. According to Foresee Pharmaceuticals founder and chairman, Ben Chien, PhD, the submission of the 3-month version of leuprolide mesylate marks a significant step in expanding treatment options for patients. The ready-to-use profile of this formulation is expected to offer a differentiated option for managing advanced prostate cancer.
Trial Design and Patient Population
The phase 3 trial enrolled patients aged 18 years or older with histologically confirmed prostate cancer who were candidates for androgen ablation therapy. Key inclusion criteria included a baseline serum testosterone level above 150 ng/dL, an ECOG performance status of 0 to 2, a life expectancy of at least 18 months, and adequate laboratory values. Exclusion criteria encompassed recent chemotherapy, immunotherapy, cryotherapy, radiotherapy, or anti-androgen therapy, as well as a history of anaphylaxis with LH-RH analogues or recent major surgery. Patients received leuprolide mesylate 25 mg on day 0, followed by a second dose on day 84, and were monitored until day 168. The primary endpoint was serum testosterone suppression from days 28 to 168, with safety serving as the secondary endpoint.
