Immutep throws its hat into the Lag3 ring

Immutep has long boasted Frédéric Triebel, the godfather of Lag3, as its chief medical officer, but it has not had much clinical data to shout about. This might have changed today with the revelation that the Tacti-002 study combining eftilagimod alpha with Keytruda has yielded impressive-looking overall survival in first-line NSCLC. This hints at the biotech having an efficacious Lag3 project, after Bristol Myers Squibb got relatlimab approved for melanoma as part of an Opdivo combo. Unlike relatlimab, efti is not an anti-Lag3 MAb but a soluble Lag3 protein designed to stimulate the immune system. Immutep’s problem is that Tacti-002 is uncontrolled, and its 25 months’ median OS in PD-L1 ≥1% expressers compares favourably only across trials in similar populations, like Cityscape (14.5 months for Tecentriq), Keytruda’s Keynote-042 (16.7 months) and Opdivo plus Yervoy’s Checkmate-227 part 1a (17.1 months). On the plus side, however, the Tacti-002 population seems broadly similar to Keynote-042’s, though in Cityscape Roche learned the hard way that phase 2 promise need not translate into a phase 3 win. Until full Tacti-002 data are presented, and until relatlimab’s own first-line NSCLC trial reads out next year, this will remain an intriguing dataset from a biotech minnow.