Alumis Stock Plummets Over 50% After Lupus Drug Fails Mid-Stage Trial

Shares of Alumis (ALMS) plummeted more than 50% in pre-market trading Tuesday after the clinical-stage biopharmaceutical company announced that its lead drug candidate failed a key study. The sell-off was triggered by news that its Phase 2b trial for treating lupus did not meet its main objectives in the overall patient population.

Trial Fails Key Endpoints

Alumis reported in a pre-market announcement on September 1 that its Phase 2b LUMUS trial evaluating envudeucitinib for moderate-to-severe systemic lupus erythematosus (SLE) did not meet its primary or secondary endpoints. The failure to demonstrate a statistically significant benefit in the broad trial population prompted an immediate and severe negative reaction from investors.

The company's stock plunged by over 54% in pre-open trading following a brief halt pending the news, with shares trading far below their previous close of $21.81.

Subgroup Analysis Offers Narrower Path

Despite the headline failure, Alumis highlighted a potential path forward based on a subset of trial participants. The company noted that a prespecified subgroup of patients with a high interferon gene signature (IFNGS-high) showed robust clinical responses across the study's main goals.

Ad

Alumis stated its intention to engage with regulators about a potential Phase 3 program targeting this specific biomarker-selected population. However, the company explained that these IFNGS-high patients were under-represented in the overall trial, which diluted the results and led to the overall trial failure.

Market Impact and Context

The negative trial data for a high-value indication like lupus overshadowed the more nuanced subgroup results, shaking investor confidence. Alumis reiterated its timeline to submit envudeucitinib for approval in plaque psoriasis in the fourth quarter of 2026, but this provided little reassurance against the significant SLE setback.

The stock's decline was exacerbated by a weak broader market, with the Nasdaq Composite and S&P 500 both trading lower. This unfavorable macroeconomic backdrop contributed to the selling pressure on a clinical-stage company absorbing a major clinical trial disappointment.