STOCKHOLM, July 13, 2023 /PRNewswire/ — Calliditas Therapeutics AB CALT (NASDAQ Stockholm: CALTX) (“Calliditas”) today announced interim data from the proof-of-concept Phase 2 trial in patients with squamous cell carcinoma of the head and neck (SCCHN) with its lead NOX 1 and 4 inhibitor product candidate, setanaxib.  The analysis reflects encouraging early clinical progression-free survival (PFS) results and is supportive of the presumed anti fibrotic mode of action of setanaxib.

The basis for the analysis consisted of a data set of 20 patients with recurrent or metastatic SCCHN, out of which 16 patients had evaluable tumor size and PFS related results. Twelve (12) patients had tumor biopsies before and after treatment that were evaluable for the biomarker analysis, which included transcriptomic analysis and also evaluated pathology markers such as SMA, Foxp3 regulatory T cells and PDL-1 CPS. Due to the small sample size and heterogeneity of the Patient population, any inferences from the interim analysis should be treated with caution.

The transcriptomic analysis showed that the two top pathways impacted by the treatment were fibrosis-related signaling pathways (the Idiopathic Pulmonary Fibrosis Signaling Pathway and Hepatic Fibrosis/Hepatic Stellate Cell Activation Pathway), providing support for the presumed mode of action relating to modulation of activated (myofibroblastic) fibroblasts, as well as the ongoing clinical programs.

Pathology analysis showed preliminary evidence of an increase in immunological activity within tumors of patients treated with setanaxib, with favorable changes in Foxp3and PDL-1 CPS. As SMA levels at baseline were not balanced between the groups, and tumor biopsy samples were generally small, it was not possible to draw any conclusions regarding setanaxib’s impact on SMA reduction.

In terms of PFS, 7 out of the 16 evaluable patients were progression-free with either stable disease or partial response, out of which 6 were in the…