Here’s Why Alumis Shares Just Cratered Over 50%

Alumis Inc. (NASDAQ: ALMS) shares collapsed on Tuesday, plunging 56.8% to $9.43 apiece after the clinical-stage biopharmaceutical company reported disappointing topline results from a pivotal mid-stage study of its lead drug candidate.

The selloff was triggered by data from the Phase 2b LUMUS trial evaluating envudeucitinib, an oral TYK2 inhibitor, in patients with moderate-to-severe systemic lupus erythematosus (SLE).

The company disclosed that the trial failed to meet both its primary and secondary endpoints, dealing a significant blow to investor confidence in the drug’s broader therapeutic potential beyond its already-established use in psoriasis.

Despite the setback, Alumis pointed to a silver lining: a subgroup analysis of patients with high interferon gene signature (IFNGS-high) showed more promising responses, and the company said it would explore this population further as it weighs a path toward a potential Phase 3 lupus program. Management emphasized that safety data from the trial were consistent with prior studies.

Envudeucitinib’s psoriasis program remains on track—two Phase 3 studies met all primary and secondary endpoints earlier this year, with the company still planning an NDA filing. Alumis also noted it ended the first half of 2026 with roughly $502 million in cash despite posting a $235 million loss, giving it a runway to continue development.

Still, the failed lupus data erased a key growth catalyst that investors had been counting on, sending the stock to multi-month lows and triggering heavy trading volume as analysts reassessed the company’s near-term valuation.