Jasper Therapeutics Faces Setback as Drug Lot Issues Impact Clinical Trial Results

Jasper Therapeutics, a California-based biotech company, experienced a significant setback in its clinical development program for briquilimab, an investigational antibody being studied for chronic spontaneous urticaria (CSU). The company reported that issues with a batch of the drug "confounded" the readout of its Phase Ib/IIa BEACON study, leading to unexpected results and a sharp decline in stock value.

Compromised Drug Lot Impacts BEACON Study

The BEACON study, a randomized, double-blinded, and placebo-controlled trial involving approximately 40 patients, was designed to evaluate briquilimab in six ascending doses for CSU treatment. However, Jasper Therapeutics revealed that a compromised drug lot affected the results of 10 out of 13 patients treated with either a single 240 mg dose or a 240 mg loading dose followed by 180 mg injections every eight weeks.

Patients who received the compromised drug showed "lower than expected" improvements in mean tryptase levels, a key pharmacodynamic outcome and biomarker of CSU. Additionally, these patients demonstrated "no discernable impact" on the Urticaria Activity Score, the study's primary efficacy measure. In contrast, two patients treated with briquilimab from a different drug lot achieved a complete response.

Financial and Strategic Implications

The news of the compromised drug lot had immediate financial repercussions for Jasper Therapeutics. The company's shares plummeted by 55% at market close on Monday, reflecting investor concerns about the trial's outcome and the potential impact on the drug's development timeline.

In response to these challenges, Jasper announced plans to implement cost-cutting measures, including a potential strategic restructuring. As of March 31, the company reported cash and cash equivalents of $48.8 million.

Analysts at BMO Capital Markets expressed skepticism about investor confidence in Jasper's stock following this update, stating, "Given the market environment, we believe investors won't feel comfortable coming back to the story following today's update."

Next Steps and Timeline Adjustments

Jasper Therapeutics is taking several steps to address the issues arising from the compromised drug lot:

1. The company is investigating the exact nature of the problem with the affected drug lot.
2. New drug product is being provided to transition the 10 affected patients to a different lot that has demonstrated efficacy in earlier cohorts.
3. An additional 10 to 12 new patients will be added across both affected dose arms to ensure a robust data set.
4. Data from these additional BEACON participants is expected to be reported in the fourth quarter.

As a result of these setbacks, Jasper has pushed back the start of a planned Phase IIb CSU study to mid-2026. Furthermore, the company has decided to discontinue the development of briquilimab for asthma, another indication that was affected by the lot issues.