Alumis Shares Plunge 55% After Lupus Drug Fails to Meet Phase 2 Trial Goals

Shares of Alumis Inc. (NASDAQ: ALMS) fell by more than half on Tuesday after the biopharmaceutical company announced its experimental lupus drug failed to meet its main goals in a mid-stage clinical trial.

The stock plunged 55% in morning trading following the disclosure of the trial results for envudeucitinib in patients with moderate-to-severe systemic lupus erythematosus (SLE).

Trial Misses Primary Goals

Alumis reported that its Phase 2b LUMUS trial, which enrolled 408 patients, did not meet its primary or secondary endpoints in the overall trial population. The primary endpoint was a measure of overall disease activity known as the British Isles Lupus Assessment Group-based Composite Lupus Assessment (BICLA) at Week 48.

According to the company, the drug was well tolerated during the study, and no new safety signals were observed. Envudeucitinib is an oral allosteric inhibitor of tyrosine kinase 2 (TYK2), a protein involved in immune system signaling.

Subgroup Shows Promise

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Despite the overall failure, Alumis highlighted what it called "robust clinical responses" in a prespecified subgroup of patients. This group, identified as having a high interferon gene signature (IFNGS-high), showed positive results on both the primary and key secondary endpoints.

The company stated that these IFNGS-high patients, who it says represent a majority of real-world SLE cases, were unexpectedly under-represented in the trial. This demographic imbalance ultimately reduced the response rates in the total study population. Alumis now plans to engage with regulators to discuss a potential Phase 3 trial focusing specifically on this IFNGS-high patient group.

Pipeline Context

The setback in lupus does not affect the drug's development for another condition. Alumis confirmed it remains on track to submit a New Drug Application for envudeucitinib for the treatment of moderate-to-severe plaque psoriasis in the fourth quarter of 2026.

That submission is based on previously announced positive results from the company's Phase 3 ONWARD program for the psoriasis indication.