Merck lines up early-stage Keytruda combo trial

Merck is planning for Keytruda’s future by launching early-stage trials of the drug in combination with an investigational treatment from US biopharma firm Syndax, entinostat.

The Phase Ib/II study will evaluate the combination in patients with either advanced non-small cell lung cancer or melanoma, and is expected to begin enrolling patients in the second half of this year.

In September Keytruda (pembrolizumab) became the first of this class of new cancer drugs, called anti-PD1 therapies, to be approved in the US as a treatment for melanoma – although in March BMS’ Opdivo (nivolumab) beat Merck to become the first anti-PD1 approved for the much larger lung cancer patient group.

Keytruda and other immuno-oncology treatments encourage the human immune system to attack cancer cells. Entinostat is a different type of cancer treatment called a selective histone deacetylase (HDAC) inhibitor, and the FDA granted its manufacturer, Syndax, Breakthrough Therapy Designation for entinostat in combination with hormone therapy in advanced hormone receptor positive breast cancer – an indication in which it is currently in Phase III trials.

There are reasons to believe the two treatments could be a complementary combination. Pre-clinical studies suggest entinostat could enhance the activity of immuno-oncology treatments like Keytruda – prompting the companies to collaborate on research.

Massachusetts-based Syndax uses an R&D technique called epigenetics – a novel way to control gene expression – to develop new treatments to avoid the problem of tumour resistance that occurs with older cancer treatments.

Syndax is also developing an immuno-oncology platform to improve people’s response to drugs like Keytruda, and holds the rights to entinostat in most major markets.

Arlene Morris, president and chief executive of Syndax, says: "We are excited to be working with Merck on this collaboration to evaluate the potential of these two novel therapies to improve clinical outcomes for patients. We hope that entinostat in combination with Keytruda may build upon the enormous promise of immunotherapy in treating multiple forms of cancer.”

Dr Eric Rubin who is the vice president and therapeutic area head for oncology and early-stage development at Merck, adds: “Our collaboration with Syndax is an important example of this effort and our commitment to further the study of breakthrough science in the area of immuno-oncology to help people with cancer.”

This week the German-based biopharma arm of Merck KGaA, Merck Serono, announced an $826 million package and an additional $115m upfront payment to license chimeric antigen receptor T-cell (CAR T-cell) cancer therapies, from Maryland-based synthetic biology company Intrexon.

Lilian Anekwe