Calliditas Therapeutics has randomised the first subject in the proof-of-concept Phase II clinical trial of setanaxib (GKT831) in individuals with squamous cell carcinoma of the head and neck (SCCHN).

Setanaxib is an inhibitor of NOX1 and NOX4.

The placebo-controlled, randomised, double-blind trial will analyse the impact of twice a day dose of 800mg setanaxib plus an intravenous dose of 200mg pembrolizumab given every three weeks.

It will enrol nearly 50 subjects with moderate or high CAF-density tumours. 

Pembrolizumab is the standard treatment regimen for this immunotherapy.

In the trial, treatment will be offered until unacceptable toxicity or progression is reported. 

The company intends to carry out the interim biomarker assessment in Q4 2022 with the final trial data expected next year. 

Calliditas Therapeutics CMO Richard Philipson said: “We believe that a successful translation into the clinic of the promising pre-clinical observations of co-administration of setanaxib and check point inhibitors, could result in important new treatment approaches for patients with CAF rich solid tumours, and we look forward to working with our clinical trial sites, investigators and site staff to successfully execute the study.”

In a Phase II trial in primary biliary cholangitis (PBC), setanaxib demonstrated evidence of anti-fibrotic activity.

Based on this data, the company is carrying out a Phase II/III trial of setanaxib in PBC and the head and neck cancer trial. 

Apart from these trials, the therapy is being analysed in two investigator-led Phase II trials for Type 1 Diabetes and Kidney Disease (DKD) and idiopathic pulmonary fibrosis (IPF), respectively.

In September 2019, the US Food and Drug Administration accepted a change in the design of part B of Calliditas’ trial of Nefecon in IgA Nephropathy (IgAN).