Cabaletta Bio shares fall on clinical trial update

Cabaletta Bio Inc. shares declined on Thursday after the company disclosed mixed data from a Phase 2 trial evaluating its lead candidate, DSG3-CAART, in patients with mucosal pemphigus vulgaris.

The biotechnology firm said the trial met its primary endpoint of safety but did not achieve statistical significance for the secondary efficacy endpoint. Cabaletta noted that while the treatment was generally well-tolerated, the efficacy signal was not as strong as anticipated, leading to investor caution.

The stock fell 12% to $4.20 in midday trading, extending losses from the prior session. The decline reflects broader concerns over the efficacy of cell therapies in autoimmune diseases, a sector that has seen heightened scrutiny following mixed results from other developers in the space.

Cabaletta Bio, which focuses on developing engineered T-cell therapies for autoimmune diseases, has emphasized the potential of DSG3-CAART to address unmet medical needs. The company plans to discuss the trial results with regulatory authorities to determine next steps, including potential modifications to the study design or additional trials.

Analysts at William Blair maintained a Market Perform rating on Cabaletta Bio, citing the need for further data to assess the therapy’s commercial viability. The firm’s price target remains at $6.50, though the outlook may shift pending additional trial results.

Investors will closely monitor Cabaletta’s upcoming presentations and regulatory interactions, as the outcome could influence sentiment in the autoimmune disease treatment space and broader biotech sector valuations.