Australian biotech company Immutep (ASX: IMM, NASDAQ: IMMP) has delivered impressive Phase I clinical trial results for its TACTI-mel trial which has observed significant tumour size shrinkage in the majority of trial patients over the 12 month trial period. 

The trials tested 24 patients with melanoma which were located in areas not capable of being removed (unresectable) or spreading to new areas of the body (metastatic). These patients had been diagnosed with low survival probabilities and/or had not responded well to Keytruda®, a more commonly used cancer immunotherapy drug. 

Key efficacy findings from the trial resulted in an Overall Response Rate of 58% (14 patients), with 71% (17 patients) identified to have had their tumours shrink by the end of the trial. 

“The combination therapy with efti shows very encouraging efficacy signals of synergy with KEYTRUDA along with a favourable safety profile so far in this high-risk patient population,” said Immutep Chief Scientific Officer and Chief Medical Officer, Dr. Frédéric Triebel.

“Patients are responding well to the combination treatment, their tumours are shrinking and not growing back over a long follow up period. 

“In addition, we have seen the complete disappearance of all target tumour lesions for six patients plus one patient with a metabolic complete response on the PET-scan. The efficacy data is now final with a long follow up, the safety assessment is ongoing.” 

TACTI-mel is a combination of Immutep’s efti, an antigen presenting cell activator, and Keytruda®. 

With results being positive from Phase I clinical trials which applied varying dosage levels, Immutep will progress its Phase II clinicals trials with a recommended efti dosage level of 30mg where Immutep plans to update the market at the Society for Immunotherapy of Cancer Conference next month.