Immunome reports 'knockout' late-stage study results for rare tumor drug

By Siddhi Mahatole

Dec 15 (Reuters) - Immunome IMNM.O said on Monday its experimental drug met the main goal in a late-stage study for patients with a rare type of tumor, sending its shares up 25% in morning trade.

The trial results set the stage for a high-stakes battle in the niche desmoid tumor market, currently dominated by SpringWorks Therapeutics' Ogsiveo, which Merck KGaA MRCG.DE acquired this year.

Immunome's once-daily oral drug, varegacestat, is being tested in patients with desmoid tumors, which are non-cancerous growths that develop in connective tissue.

While they do not spread to other parts of the body, they can recur after treatment.

The trial showed varegacestat significantly improved progression-free survival compared with a placebo, cutting the risk of disease progression or death by 84%.

"While the efficacy data looks numerically better for varegacestat relative to Ogsiveo and detailed data is needed to fully assess the competitive threat, we see the threat as already being largely anticipated by the market," said J.P. Morgan analyst Richard Vosser.

Varegacestat belongs to a class of drugs called gamma secretase inhibitors that target pathways linked to desmoid tumors.

In the late-stage study of 156 patients, 56% of those who received the drug had their tumors shrink or disappear, compared with only 9% of patients on placebo.

Evercore ISI analyst Cory Kasimov called the data a "knockout", noting investors were expecting for about a 50% response rate to set the drug apart.

Immunome said the treatment met all key secondary goals, including reducing tumor size and easing pain compared with the placebo, after 24 weeks of treatment.

CEO Clay Siegall said Immunome has received interest from companies exploring potential collaborations, but "the default is that we're going to launch this drug in major markets".

The drug developer plans to seek U.S. approval for varegacestat in the second quarter of 2026.