Syndax shares fall 15% after axatilimab trial failure, halt to pulmonary fibrosis development
Key Facts
Syndax Pharmaceuticals announced on October 12, 2026, that a trial of axatilimab for idiopathic pulmonary fibrosis had failed and said it would not pursue development for the disease. The company said in a statement on the MAXPIRE trial results that the study "did not meet its primary endpoint." That endpoint measured the annual rate of decline in forced vital capacity among trial participants. The decision to halt development was based on these results, ending testing of the drug for this indication. The setback comes in a disease for which there is currently no cure, according to the U.S. National Institutes of Health's National Heart, Lung, and Blood Institute.
The phase two trial enrolled 145 patients and lasted 26 weeks, according to details released by Syndax. The study used a randomized, double-blind design, with a placebo used to compare the two groups of participants. Enrollment spanned 62 research sites in 14 countries in the multicenter trial. Before the results were released, Jefferies said it wanted to see an improvement in forced vital capacity of more than 30 milliliters versus placebo at week 26 to bolster its confidence in the drug's potential, according to Investing.com. As background to this treatment program, the National Heart, Lung, and Blood Institute says some available treatments may slow the progression of idiopathic pulmonary fibrosis.
The drug is approved in the United States under the brand name Niktimvo to treat chronic graft-versus-host disease. The U.S. Food and Drug Administration granted approval on August 14, 2024, according to its announcement on the drug. The indication covers adults and children weighing at least 40 kilograms who have received at least two prior systemic therapies. In the approval study for this disease, the overall response rate was 75% among 79 patients who received the recommended dose, according to the FDA. Axatilimab is an antibody that blocks the colony-stimulating factor one receptor, according to the agency's description of its mechanism of action.
On the commercial front, Syndax reported net revenue from Niktimvo of $60.3 million in the second quarter of 2026. The company had reported net revenue from the drug of $55.1 million in the first quarter of the same year. Second-quarter revenue thus exceeded the previous quarter's level, according to the financial results the company published for each period. The collaboration agreement between Syndax and Incyte provides for a 50:50 split of U.S. profits, according to the agreement announcement. The agreement also made Syndax responsible for funding the initial development of axatilimab in idiopathic pulmonary fibrosis, the program the company decided to halt following the results.
In the market, Syndax shares fell 15% in after-hours trading on October 12 following the announcement of the trial results, according to Investing.com. On October 13, Bank of America Global Research cut its price target for the stock to $23 after the study failed, according to the website. Its previous price target was $26 a share. Stifel, meanwhile, said its estimates already assigned no value to the axatilimab program in idiopathic pulmonary fibrosis, according to Investing.com. The website quoted the firm as saying its estimates had given the program "zero credit" in its previous valuation of this potential indication.
On safety, Syndax said the safety and tolerability profile in the MAXPIRE trial was similar to placebo, with no new safety signals identified. The company said the study results do not affect ongoing axatilimab trials in other potential indications. Upcoming milestones include results from a trial combining axatilimab and ruxolitinib in patients with newly diagnosed chronic graft-versus-host disease, which the company expects in the fourth quarter of 2026. Development plans also include a pivotal trial combining axatilimab and corticosteroids in patients newly diagnosed with the same disease. According to the outlook Syndax provided in its financial results announcement, results from this pivotal trial are expected in early 2028.