Syndax Pharmaceuticals, Inc.Syndax Pharmaceuticals, Inc. (“Syndax,” the “Company” or “we”) (NASDAQ:SNDX), a clinical-stage biopharmaceutical company developing an innovative pipeline of cancer therapies, today announced updated positive data from its Phase 1/2 trial of axatilimab in patients with recurrent or refractory chronic graft-versus-host disease (cGVHD) despite two or more prior lines of therapy. Axatilimab is the Company’s anti-CSF-1R monoclonal antibody. The data are being featured during an oral session at the 63rd American Society of Hematology (ASH) Annual Meeting on Saturday, December 11, 2021 at 3:05 p.m. ET.

“There exists an urgent need for novel and effective therapies in patients with cGVHD,” said Michael Meyers, M.D, M.P.H., Chief Medical Officer of Syndax. “The broad activity and tolerability observed underscores axatilimab’s potential to play a meaningful role in the cGVHD treatment landscape, and further supports the importance of the ongoing AGAVE-201 trial.”

“Durable responses and multiorgan clinical benefit reported today from the ongoing pivotal Phase 2 AGAVE-201 trial continue to support axatilimab’s potential to serve as an intervention for patients with cGVHD,” said Briggs W. Morrison, M.D., Chief Executive Officer of Syndax. “We are committed to maximizing the clinical impact of axatilimab across multiple lines of treatment in cGVHD as well as additional fibrotic diseases where the monocyte-macrophage lineage plays a vital role, such as idiopathic pulmonary fibrosis. We look forward to providing updates on our progress in the coming months.”

A total of 40 patients with refractory disease who received a median of four prior systemic therapies, including ibrutinib, ruxolitinib, and belumosudil, were treated in the Company’s Phase 1/2 trial of axatilimab. As of an October 22, 2021 data cutoff date, 31 patients treated at two of the doses being tested in the Company’s ongoing AGAVE-201 global pivotal study were evaluable for response. A best ORR (complete response + partial response) of 72% (18/25) at 1mg/kg every two weeks and 50% (3/6) at 3mg/kg every four weeks was observed, for an ORR of 68% (21/31). Of note, responses were observed across a range of organ systems with difficult to treat manifestations such as lung (5/15), skin (3/28), and joints and fascia (16/24). Fifty-three percent of patients reported clinically meaningful improvement in their symptoms via the Lee Symptom Scale. As of the data cutoff date, 43% (17/40) of patients remained on treatment.

Axatilimab was well-tolerated with a favorable safety profile. The most common adverse events were consistent with on-target effects on liver enzyme pharmacology. There was no incidence of cytomegalovirus (CMV) or other viral reactivation, and no apparent increases in risk for infection.

Enrollment is ongoing in the Company’s global pivotal Phase 2 AGAVE-201 trial of axatilimab in patients with cGVHD, with topline data expected in 2023. The trial will evaluate the safety and efficacy of three doses and schedules of axatilimab. The primary endpoint will assess objective response rate based on the 2014 NIH consensus criteria for cGVHD, with key secondary endpoints including duration of response and improvement in modified Lee Symptom Scale score.

A copy of today’s presentation will be available in the Publications and Meeting Presentations┬ásection of Syndax’s website.