NEW YORK – Foghorn Therapeutics said on Monday it has dosed the first patient in a Phase I study of its BRD9 protein degrader FHD-609 in patients with advanced synovial sarcoma.
Researchers will enroll 70 patients with advanced synovial sarcoma in the dose-escalation and expansion stage of the study. They will evaluate FHD-609's safety profile and anti-tumor activity in these patients.
All synovial sarcoma tumors are characterized by a genomic alteration, the translocation t(X;18)(p11;q11), which results from the enjoining of the SS18 gene with SSX1, SSX2, or SSX4 genes. These rearrangements occur in the same pathway as BRD9 and make synovial sarcomas genetically dependent upon the protein.
In preclinical studies, FHD-609 has been shown to degrade BRD9. To enroll in the Phase I study, patients must have a diagnosis of synovial sarcoma defined by the presence of a SS18-SSX rearrangement. Study participants may also be previously treated with no more than four systemic chemotherapies and have progressed or discontinued their prior treatment due to toxicity, intolerability, or lack of clinical benefit.
This year, Foghorn also began a Phase I trial of its BRG1 and BRM inhibitor FHD-286 in metastatic uveal melanoma. The company is also studying FHD-286 in advanced hematologic cancers, including acute myeloid leukemia and myelodysplastic syndromes.