A New Front in Prostate Cancer: AB Science Secures 20-Year US Patent

PARIS, FRANCE – June 17, 2026 – In a move that significantly reinforces its strategic position in the oncology market, French pharmaceutical firm AB Science announced it has been formally granted a United States patent for its lead compound, masitinib. The patent, which protects the drug’s use in treating metastatic castrate-resistant prostate cancer (mCRPC) until May 2042, provides a nearly two-decade runway of intellectual property protection in the world’s largest pharmaceutical market. This development, which builds on existing patent coverage in Europe, is more than a legal victory; it’s a critical enabler for a new, targeted approach to a disease that has seen limited therapeutic advancement for twenty years.

A Strategic Shield in a High-Stakes Market

For a company like AB Science, which specializes in developing protein kinase inhibitors for diseases with high unmet needs, long-term patent protection is the bedrock of its business model. The newly issued US patent (US 12,648,944) provides market exclusivity that is essential for recouping the immense costs of drug development and funding future research. This is particularly crucial in the highly competitive and lucrative oncology space. The global market for mCRPC therapies was valued at approximately $6.8 billion in 2023 and is projected to grow substantially, with some estimates placing its value over $22 billion by 2032. Securing a piece of this market hinges on both clinical efficacy and robust intellectual property.

The patent grant arrives at a pivotal time for AB Science. The company, which has strategically focused its R&D spending on its most promising assets, including masitinib for Amyotrophic Lateral Sclerosis (ALS), can now proceed with its mCRPC program with greater financial certainty. The extended patent life makes masitinib a more attractive asset for potential partnerships and provides the stability needed to navigate the final, most expensive stages of clinical development and commercialization. It’s a strategic shield that allows the company to focus on the science, confident that a potential market success will be protected.

Redefining Treatment with a Biomarker-Driven Approach

Beyond the corporate strategy, the real significance of masitinib lies in its novel approach to treating mCRPC. This aggressive form of prostate cancer develops when the disease progresses despite hormone therapies designed to lower testosterone levels. It is a lethal condition, with a five-year survival rate of approximately 32%. For two decades, the chemotherapeutic agent docetaxel has been a standard of care, yet numerous attempts to combine it with other drugs to improve patient outcomes have largely failed to move the needle on survival rates. This has created a significant unmet need for new therapeutic combinations.

Masitinib aims to break this stalemate not by treating all patients, but by targeting a specific subpopulation. The patent and the underlying clinical program focus on mCRPC patients with low metastatic involvement, identified using a common biomarker: baseline alkaline phosphatase (ALP) levels. This biomarker-driven strategy is a hallmark of modern precision medicine. By selecting patients with ALP levels at or below 250 IU/L, AB Science is targeting a group more likely to respond to masitinib’s mechanism of action.

The approach is validated by the company’s Phase 3 study, AB12003. The trial demonstrated that adding masitinib to a standard docetaxel regimen resulted in a significant clinical benefit for this targeted group. Patients receiving the combination saw a 21% reduction in the risk of disease progression or death compared to those receiving docetaxel alone. The progression-free survival (PFS) rates at 12, 18, and 24 months were all significantly higher in the masitinib arm, indicating a durable effect. As one medical expert noted, “Identifying which patients will benefit most from a therapy before you start treatment is the holy grail in oncology. Using a simple, accessible biomarker like ALP to guide the use of masitinib is a clinically elegant and powerful approach.”

The Path Forward: From Clinical Trials to the Clinic

The patent grant is a milestone, not a finish line. The next critical step for AB Science is to replicate the promising results of the AB12003 study in a confirmatory Phase 3 trial. This new study, designated AB22007, has already received authorization from both the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA), signaling regulatory alignment with the drug’s development pathway. The trial is designed to enroll 600 mCRPC patients from the targeted low-ALP subpopulation and will measure radiographic progression-free survival (rPFS) as its primary goal.

Successfully navigating this confirmatory trial is paramount. The history of oncology is littered with promising agents that failed in late-stage studies. However, masitinib’s targeted approach may give it an edge where broader, untargeted therapies have faltered. The competitive landscape for mCRPC remains intense, with new classes of drugs like PARP inhibitors and radiopharmaceuticals gaining ground. Yet, the specific niche masitinib is targeting—a first-line combination with docetaxel for a biomarker-defined population—remains an area of opportunity.

The development program in prostate cancer is also part of a broader platform strategy for masitinib, which is being investigated in other challenging diseases like ALS and multiple sclerosis. This diversification spreads risk and highlights the potential of the molecule's unique mechanism of action across different pathologies. For now, all eyes in the prostate cancer community will be on the progress of the AB22007 study, which represents the final hurdle between a promising scientific concept and a new standard of care for a vulnerable patient population.