Drug Development · us
With Acute Pancreatitis Trials Lacking an Established Endpoint, Auxora Puts Severe Respiratory Failure in the Lead
The FDA and CalciMedica have reached agreement on the primary endpoint for the next-stage trial, but the respiratory failure signal supporting this development pathway comes from only a small number of events and still requires validation in a prospective study.
After hospitalization for acute pancreatitis, the real threat to life often lies not only in the pancreas itself, but in inflammation spreading throughout the body and ultimately impairing the lungs and other organs. Yet in this field, which has no approved drugs, there is not even a mature precedent for an efficacy endpoint capable of supporting a registrational trial. CalciMedica now says it has reached agreement with the U.S. Food and Drug Administration (FDA) on how to assess Auxora in its next late-stage Phase 2 trial, providing a clearer regulatory path for the development program.
According to the Type C meeting outcome announced by the company, new-onset severe respiratory failure will be the primary endpoint, while multiple organ failure and time to meeting medical criteria for discharge will be key secondary endpoints. The trial will also help confirm patient selection criteria and guide endpoint selection for a Phase 3 trial. The full Phase 3 design still needs to be discussed at subsequent meetings, so the current agreement does not mean that the FDA has determined the drug to be effective, nor does it constitute a commitment to approval.
Auxora, also known as zegocractin, is an intravenous calcium release-activated calcium (CRAC) channel inhibitor. These channels are involved in cytokine release by immune cells and also regulate calcium influx in endothelial cells and organ tissues. By inhibiting overactivated signaling, CalciMedica hopes to reduce both systemic inflammation and vascular and tissue damage, preventing progression to respiratory failure.
The basis for the new endpoint comes from the completed CARPO randomized, double-blind, placebo-controlled trial. The study enrolled 216 patients with acute pancreatitis and systemic inflammatory response syndrome, with 214 included in the modified intention-to-treat analysis. The trial's original primary endpoint—time to recovery of tolerance for solid food—was not met in the overall population; a clearer signal emerged only in certain patients with higher hematocrit or more severe lesions on imaging.
The respiratory failure results were more striking, but they must also be interpreted in the context of the sample size: four patients in the placebo group developed new-onset severe respiratory failure, as did four in the low-dose group, while there were no cases in either the medium- or high-dose groups. The company's claimed “complete reduction” is therefore based on a small number of events, and this was originally a secondary endpoint. Elevating it to the primary endpoint in the next trial is intended to determine whether the signal can be replicated in a prespecified study with greater statistical power.
The trial will also prospectively evaluate whether lactate dehydrogenase (LDH) can serve as an enrichment biomarker. An exploratory analysis of CARPO showed that patients with higher baseline LDH were more likely to develop severe respiratory failure and also had higher interleukin-6 concentrations. LDH testing is rapid and widely available, but it reflects broad tissue damage rather than being specific to pancreatitis. Whether it can consistently identify patients most likely to deteriorate and most likely to benefit remains a question the new trial must answer.
CalciMedica has not yet disclosed the trial's planned enrollment, start date, or statistical assumptions, and the FDA meeting minutes have not been made public. At this stage, the description of the regulatory agreement comes primarily from the company. Regarding safety, a trial of the same drug in acute kidney injury was previously paused because of an imbalance in deaths. The company and external experts said they found no drug-related toxicity, and the FDA subsequently raised no comments on the revised protocol, but the company currently has no plans to resume dosing in that trial. For Auxora, the next step is not only to show that an endpoint can be measured, but also to demonstrate that an early signal from a small number of events can translate into credible clinical benefit.