Calliditas announces positive topline results of phase 2 head and neck cancer trial

Calliditas-announces-positive-topline-results-of-phase-2-head-and-neck-cancer-trial.jpg
© Getty Images (Getty Images)

Calliditas Therapeutics has announced encouraging data from its proof-of-concept phase 2 trial evaluating setanaxib, its lead NOX enzyme inhibitor, in combination with pembrolizumab, in patients with squamous cell carcinoma of the head and neck (SCCHN).

The analysis showed statistically significant improvements in progression-free survival (PFS), as well as in overall survival (OS), with notable changes in tumor biology consistent with the mechanism of action of setanaxib.

“This is a very exciting result which provides clinical evidence of the mode of action of setanaxib in line with our thesis of its anti-fibrotic effects, and with results beyond our expectations for a study of this size. It is exciting that we now have positive clinical evidence in support of our first in class NOX platform” said Renée Aguiar-Lucander, CEO of Calliditas. 

In the study, researchers investigated the effects of combining setanaxib with pembrolizumab, a standard treatment.

The trial involved 55 patients with moderate or high levels of Cancer Associated Fibroblasts (CAFs) in their tumors. Patients received either setanaxib or a placebo alongside pembrolizumab and were monitored for at least 15 weeks.

Results showed that patients receiving both setanaxib and pembrolizumab experienced significant improvements compared to those on pembrolizumab alone.

These improvements included longer progression-free survival (median 5 months vs. 2.9 months) and better overall survival rates at 6 and 9 months.

Additionally, more patients on setanaxib showed disease stabilization compared to those on the placebo.

While there was no significant difference in tumor size reduction between the groups, analysis of tumor samples revealed increased CD8+ T-cells in those treated with setanaxib, suggesting enhanced immune response, which aligns with setanaxib's mechanism of action.

The combination treatment was well-tolerated with no new safety concerns.

“It is very encouraging to see statistical significance on important clinical outcomes in this relatively small study, which provides an excellent basis for advancing setanaxib in this hard-to-treat population,” added Kevin Harrington, investigator on the trial and professor in biological cancer therapies at the Institute of Cancer Research (ICR), London. 

Moving forward, the company is conducting additional clinical trials with setanaxib and will read out its phase 2 trial in PBC (primary biliary cholangitis) in Q3 of 2024.

“I am delighted that we have seen statistical significance and clinically meaningful improvements in longer term outcomes of PFS and OS in this indication. I’d like to extend my thanks to investigators, clinical trial site staff, and most importantly patients, who have all contributed to this important study," commented Richard Philipson, chief medical officer at Calliditas. 

The company also plans to arrange an research and development (R&D) day in Stockholm later this month to provide additional details regarding the phase 2 trial and other data supporting the mechanism of action of setanaxib.