Another day, another immuno-oncology tie up, and this time it’s Merck & Co and Syndax combining two of their anti-cancer drugs in the hope of magnifying their power.

The collaboration will see Merck’s checkpoint inhibitor Keytruda (pembrolizumab) tested in combination with Syndax’ entinostat in a Phase Ib/II clinical programme in melanoma and non-small cell lung cancer, that could be extended into Phase III.

Keytruda is the first US-approved drug that blocks the PD-1 (programmed death receptor-1) cellular pathway, which restricts the body’s immune system from attacking certain cancer cells. 

Entinostat is an oral, highly-selective HDAC inhibitor that has been granted Breakthrough Therapy Designation as well as a Special Protocol Assessment (SPA) for an ongoing Phase III clinical trial in hormone-resistant breast cancer.  

Data has shown that entinostat can boost the effect of checkpoint inhibitor therapies, resulting in a greater immuno-response to tumour cells, prompting the companies to test whether the Keytruda/entinostat combo is more powerful than either component alone.

Financial terms of the deal were not disclosed.