PT-112 Phase 2 Trial Enrollment Complete in Advanced Prostate Cancer Patients

Promontory Therapeutics, a pharmaceutical firm specializing in immunogenic small molecule therapies, has successfully completed the patient enrollment phase for its Phase 2 clinical trial of PT-112, a novel therapeutic candidate. The trial has reached its target of 109 participants, spread across clinical sites in both the United States and France. These patients have metastatic castration-resistant prostate cancer (mCRPC) and have undergone at least three prior treatments, with the trial also including those with bone-only metastatic disease.

The trial's design is an open-label dose optimization and proof of concept study for PT-112 as a monotherapy. It is set to provide interim data results, with the primary data and conference presentations anticipated to be disclosed by the end of 2024. PT-112 has been shown in earlier studies to be safe and efficacious, promoting a form of cancer cell death that stimulates an immune response, a particularly promising approach for treating prostate cancer, which is typically considered an 'immune-cold' disease.

Johan Baeck, MD, the Chief Medical Officer of Promontory Therapeutics, highlighted the significance of the trial, stating it is the largest to date for PT-112 and is expected to determine the optimal dosage in alignment with FDA's Project Optimus. The study also aims to produce supportive data through correlative research, focusing on the immune response triggered by PT-112, the proliferation of new T cell populations, and the reduction of circulating tumor cells and ctDNA.

Robert Fallon, CEO of Promontory Therapeutics, expressed gratitude to clinical partners, including Gustave Roussy Paris, for their role in the trial's enrollment. He also voiced confidence in PT-112's potential as an effective treatment for mCRPC patients who have exhausted other therapeutic options and have no effective immunotherapy available to them.

PT-112 is distinguished as the first pyrophosphate small-molecule conjugate in clinical development for oncology. It offers several advantages, such as its tolerability and its unique mechanism that leads to immunogenic cell death, making it a strong inducer of an immunological response against cancer. PT-112 also exhibits osteotropism, concentrating in areas of the bone, which is beneficial for treating cancers that affect the bone. Prior studies have shown PT-112's safety and potential for long-lasting responses in heavily pre-treated patients.

Promontory Therapeutics, based in New York City, is privately held and has a focus on small molecule immunotherapy. The company has ongoing Phase 2 studies for PT-112 and has demonstrated promising results in clinical trials across different regions. Promontory Therapeutics is also engaged in a formal collaboration with the National Cancer Institute (NCI) for the treatment of thymic epithelial tumors, a rare form of cancer, and has received Orphan Drug designation for PT-112 in this context. The company is recognized as a member of the Paris-Saclay Cancer Cluster and was nominated for the Prix Galien USA's Best Startup in 2023.