Hemispherx Biopharma has started dosing patients in a Phase I clinical trial evaluating its Ampligen (rintatolimod) plus Merck‘s Keytruda (pembrolizumab) for the treatment of triple-negative breast cancer.

Ampligen is a dsRNA TLR3 agonist, while Keytruda is an anti-PD-1 check-point blocker.

Sponsored by Roswell Park Comprehensive Cancer Center, the Phase I trial will assess the safety and efficacy of Ampligen-based chemokine modulation therapy when given before pembrolizumab in around six metastatic triple-negative breast cancer patients.

This chemokine modulation treatment will involve celecoxib, recombinant interferon alfa-2b and Ampligen.

“Making tumours easier targets for checkpoint blockade therapies creates an exciting new approach.”

The therapeutics are expected to boost the existing cancer immune responses by blocking inhibitory molecules or activating stimulatory molecules.

Investigators aim to evaluate if this therapy approach would lead to positive changes in the tumour microenvironment.

These modifications are expected to transform previously ‘cold’ tumours that are not susceptible to checkpoint blockade therapy into ‘hot’ tumours primed for the therapy.

Hemispherx Biopharma CEO Thomas Equels said: “Our extensive work with Ampligen has led many top oncologists to conclude, including in peer-reviewed medical journal articles, that Ampligen has the potential to change the tumour microenvironment.

“Making tumours easier targets for checkpoint blockade therapies creates an exciting new approach with the potential to significantly improve clinical outcomes for patients in multiple solid tumour cancer types.”

The primary outcome measure of the Phase I trial is overall response rate (ORR). Its secondary outcomes include progression-free survival (PFS), overall survival (OS), disease control rate (DCR) and incidence of adverse events.

The study is expected to be completed in 2022.