Biothera plans to evaluate combination therapy of Imprime PGG and Merck’s Keytruda

Merck will provide funding and clinical supplies of pembrolizumab for the investigator-initiated study, which is anticipated to start in the first quarter of next year.

Imprime PGG is a systemically administered beta glucan pathogen associated molecular pattern that triggers an immune response demonstrated to improve the anti-tumor efficacy of checkpoint inhibitors (PD-1, PD-L1 antibodies), anti-angiogenic antibodies and tumor-targeting monoclonal antibodies (mAbs).

It has so far demonstrated efficacy in combination with mAbs in two Phase 2 trials of NSCLC patients.

Under the Phase 1b/2 study, about 58 patients with NSCLC will be enrolled following their progression on first line platinum-based chemotherapy.

About 12 patients will receive Imprime PGG in combination with pembrolizumab in the phase 1b part of the dose-escalation study.

The 46-subject phase 2 element of the study will evaluate whether the addition of Imprime PGG to pembrolizumab increases median progression free survival and overall survival.

Biothera Pharmaceutical chief medical officer Jose Iglesias said: "Imprime PGG acts as an ignition switch to drive a coordinated response involving both the innate and adaptive immune systems to recognize and kill cancer cells.

"In the anticipated Phase 1b/2 study, Imprime is expected to perform a dual role of enhancing antigen presentation, which helps more T cells target cancer, and upregulating PD-L1 expression to provide pembrolizumab more opportunities to disrupt or inhibit PD-1/PD-L1 interaction."

Imprime PGG has been well-tolerated in trials in more than 400 patients. It has established proof of concept in several clinical studies in NSCLC, colorectal cancer, and chronic lymphocytic leukemia.

Biothera is also undertaking trails in metastatic colorectal cancer and non-Hodgkin’s lymphoma.

Image: Biothera Pharmaceutical headquarters in the US. Photo: courtesy of Biothera, the immune health company.