Alumis (ALMS) Stock Plunges 56% After Lupus Trial Disappointment

Key Takeaways

Table of Contents

Shares of Alumis plummeted approximately 56% following disappointing results from the Phase 2b LUMUS study, where envudeucitinib failed to achieve primary and secondary goals in lupus patients.
The study included 408 participants but did not meet its main objective of reducing disease activity at the 48-week mark.
A predetermined subset of patients with elevated interferon gene signatures demonstrated encouraging results, though this cohort represented a smaller portion of trial participants than anticipated.
The company maintains its timeline to submit regulatory approval for envudeucitinib in plaque psoriasis during the fourth quarter of 2026, supported by favorable Phase 3 data.
Management plans to discuss a potential Phase 3 trial concentrating on IFNGS-high lupus patients with regulatory authorities.

Shares of Alumis experienced a devastating decline of approximately 56% on Tuesday following the company’s announcement that its Phase 2b LUMUS clinical trial of envudeucitinib failed to demonstrate efficacy in patients suffering from moderate-to-severe systemic lupus erythematosus (SLE).

The stock plunged as much as 57.86% during trading. This represents a devastating one-day collapse for the biotech company.

Alumis Inc., ALMS

The clinical study recruited 408 participants and evaluated disease progression using the British Isles Lupus Assessment Group-based Composite Lupus Assessment (BICLA) at the 48-week timepoint. This served as the study’s primary objective, which was not achieved.

Additional secondary objectives across the broader patient population also failed to reach statistical significance.

Management highlighted one encouraging finding. A predetermined subset of participants with elevated interferon gene signatures, designated as IFNGS-high, demonstrated significant clinical improvements on both the main endpoint and crucial secondary measurements.

🚨 ALUMIS $ALMS JUST COLLAPSED 55% AFTER ITS LUPUS CLINICAL TRIAL FAILED$ALMS erased $1.5B in valuation today after its 408-patient Phase 2b LUMUS trial missed its primary endpoint despite being described as “potentially pivotal.”
The drug showed promise in patients with… pic.twitter.com/Bpfpv2gKMQ
— Limitless Finance (@trylimitlessfin) September 1, 2026

Patients with IFNGS-high characteristics represent the majority of moderate-to-severe SLE diagnoses. However, this subpopulation was surprisingly underrepresented in the current study, which negatively impacted overall trial outcomes.

The company reported that envudeucitinib demonstrated a favorable safety profile across the trial duration. No unexpected adverse events were identified.

Pharmacodynamic analysis additionally verified substantial dose-related suppression of the interferon pathway, with the maximum dose of 40mg administered twice daily achieving optimal pathway inhibition.

Alumis’s Strategic Direction

Management indicated plans to consult with regulatory agencies regarding the development of a Phase 3 clinical program targeting exclusively the IFNGS-high patient segment.

The company emphasized that no targeted oral treatment options currently exist for SLE, which it believes justifies continued investment in this therapeutic area.

Development in psoriasis continues without disruption. The company maintains its schedule to file a New Drug Application for envudeucitinib in moderate-to-severe plaque psoriasis during the final quarter of 2026.

This regulatory submission builds on encouraging results from the company’s Phase 3 ONWARD clinical program in plaque psoriasis.

Understanding Alumis’s Position

Envudeucitinib functions as an oral allosteric inhibitor targeting tyrosine kinase 2 (TYK2). Its therapeutic effect comes from modulating immune signaling pathways regulated by IL-23, IL-17, and Type I interferon.

The compound’s mechanism of action remains consistent across both lupus and psoriasis indications, which explains why the IFNGS-high subset findings maintain relevance for investors and analysts monitoring the development pipeline.

The company’s valuation reached approximately $2.99 billion prior to Tuesday’s sharp decline. Year-to-date performance had shown gains exceeding 123% before the trial announcement.

Typical daily share volume averaged roughly 1.29 million shares preceding the release of trial data.

Technical indicators had assigned a Hold rating to the stock before the clinical results were disclosed.