Tuesday, June 27, 2023
AB Science SA has announced that it has received a Notice of Allowance from the European Patent Office for a patent regarding the treatment of metastatic castration-resistant prostate cancer (mCRPC) using its primary compound, masitinib. The patent is based on the findings from study AB12003  and provides intellectual property protection for masitinib in mCRPC treatment until 2042.
Masitinib is used in combination with docetaxel to treat eligible mCRPC patients following chemotherapy, specifically after metastatic hormone-sensitive prostate cancer (mHSPC) treatment.
Although there are various treatments available for mHSPC, there is currently no registered drug for use in combination with docetaxel in mCRPC patients, despite docetaxel's approval nearly two decades ago. Most trials exploring combinations of docetaxel and new targeted agents have failed, making study AB12003 a rare example of a phase 3 clinical trial that demonstrated improved progression-free survival (PFS) when masitinib was combined with docetaxel.
The Notice of Allowance (NOA) signifies the intention of the European Patent Office to grant the patent application, EP4175639A1, pending completion of procedural steps. Once granted, the patent will be valid until May 2042. A European NOA is issued when the examiner determines that a patent application fulfills the requirements for patentability under the European Patent Convention.
The patent provides protection for masitinib and related compounds in the treatment of mCRPC in a specific patient subgroup with low metastatic involvement, as indicated by baseline alkaline phosphatase levels. This patient population aligns with the findings of masitinib study AB12003  and the ongoing clinical development program for mCRPC.
To summarize the key results of study AB12003:
- Masitinib (6.0 mg/kg/day) in combination with docetaxel showed a significant benefit in progression-free survival (PFS) for mCRPC patients with baseline alkaline phosphatase levels (ALP) of 250 IU/L or less. The hazard ratio was 0.79 [0.64, 0.97] (p=0.0087), corresponding to a 21% reduction in the risk of progression compared to the control group.
- The assessment of PFS rates supported the primary outcome, with significant improvement favoring the masitinib plus docetaxel group over the control group at 12, 18, and 24 months. The improvement was 1.6-fold (p=0.0035), 1.9-fold (p=0.0001), and 1.9-fold (p=0.0028), respectively.
- The treatment effect of masitinib was more pronounced in patients with lower baseline ALP levels, indicating less advanced metastatic disease. Patients with ALP levels of 100 IU/L or less experienced a significant 47% reduced risk of progression (hazard ratio=0.53, p=0.002).
- The safety profile of masitinib plus docetaxel was acceptable and consistent with the known safety profile of masitinib, with no new safety concerns observed.
While localized prostate cancer has higher survival rates, metastatic prostate cancer remains an unmet medical need, with a 5-year survival rate of approximately 32% .