Sumitomo Pharma continued to build momentum for its rare disease drug discovery efforts by acquiring its fourth US Food and Drug Administration (FDA) Orphan Drug Designation in the last 12 months.

On April 10, the Japanese pharma giant announced it received the FDA designation for TP-1287 in the rare bone cancer Ewing sarcoma. Sumitomo is currently developing TP-1287 in a Phase I trial targeting advanced solid tumors (NCT03604783) through its Cambridge, Massachusetts-based subsidiary Sumitomo Pharma Oncology.

Sumitomo’s TP-1287 joins three of the company’s other early-stage candidates to recently earn the important regulatory status. This includes the mixed-lineage leukemia (MLL) inhibitor DSP-5536 in acute myeloid leukemia (NCT04988555); the PIM kinases inhibitor TP-3654 for myelofibrosis (NCT04176198); and the emopamil-binding protein (EBP) inhibitor DSP-0390 for brain cancer (NCT05023551).

Orphan drug designation

TP-1287 earned an FDA Orphan Drug Designation amid an industry-wide surge in the regulatory program’s popularity. In the past decade, the FDA has doubled the number of new designations granted compared to the preceding decade. Therapies for oncology, and in particular rare genetic cancers, have made up the majority of orphan drug designations.

The FDA grants Orphan Drug Designation to experimental therapies targeting rare diseases affecting fewer than 200,000 US patients, offering potential tax credits and up to seven years of market exclusivity for therapies. Ewing sarcoma is an ultra-rare cancer occurring in bones or the surrounding soft tissue, causing fewer than 1,000 annual cases in the US.

TP-1287 is an oral small molecule that inhibits cyclin-dependent kinases, which play a role in cell cycle regulation. The drug also received the FDA’s Rare Pediatric Disease Designation, designed for serious or life-threatening diseases occurring primarily in patients under 18 years, in Ewing sarcoma.

Sumitomo’s US-based, 80-patient Phase I trial of TP-1287 has an estimated primary completion date of June 2024, per the trial listing.