FDA Designates Axatilimab an Orphan Drug for IPF

Axatilimab, an investigational therapy being developed by Syndax Pharmaceuticals, has been granted orphan drug designation by the U.S. Food and Drug Administration (FDA) as a potential treatment for idiopathic pulmonary fibrosis (IPF).

The FDA gives orphan drug status to medications that have the potential to substantially improve care for people with rare diseases — defined as those affecting fewer than 200,000 people in the U.S. The designation qualifies therapy developers for certain incentives, including tax credits, fee waivers, and the potential for seven years of market exclusivity if the treatment is ultimately approved.

“IPF is a serious, life-limiting orphan disease, and today’s Orphan Drug Designation validates axatilimab’s potential to serve as an effective therapeutic option for the currently underserved patients living with this rare disease,” Briggs W. Morrison, MD, Syndax’s CEO, said in a press release.

Axatilimab is a monoclonal antibody that binds and blocks the activity of a protein receptor called colony stimulating factor-1 receptor (CSF-1R). The activation of this receptor is important for the survival and function of certain types of immune cells called monocytes and macrophages, which are thought to be important drivers of IPF and other fibrotic diseases. Such disorders are characterized by erroneous scar tissue (fibrosis) formation.

According to Syndax, preclinical data indicate that treatment with axatilimab has fibrosis-limiting effects in models of IPF, as well as in chronic graft versus host disease (cGVHD). cGVHD is a serious and potentially life-threatening complication of stem cell transplants that can lead to scar tissue formation in all internal organs.

An ongoing Phase 1/2 trial (NCT03604692) is investigating Axatilimab in people with active cGVHD. Early data from the study showed axatilimab was generally safe and well-tolerated, and able to elicit deep and sustainable responses that resulted in clinically meaningful benefits for multiple internal organs in patients who ceased responding to other therapies.

Meanwhile, the company has launched a Phase 2 trial, called AGAVE-201 (NCT04710576), that seeks to assess the safety, tolerability, and efficacy of different doses of axatilimab in people with active cGVHD whose disease returned or ceased responding to other treatments. That trial is based at the Indiana University Health Melvin and Bren Simon Cancer Center, in Indianapolis.

“Building on promising data demonstrating meaningful multiorgan clinical benefit in patients with chronic graft versus host disease, we are actively evaluating options to expand the axatilimab franchise into additional areas of high unmet need where the monocyte-macrophage lineage plays a key role in the fibrotic disease process. We look forward to providing updates on these plans in the coming months,” Morrison said.

The FDA has previously granted orphan drug designation to axatilimab for the treatment of cGVHD.