Merck wins race to market PD-1 inhibitor in US

Merck has gained US FDA accelerated approval for new generation drug Keytruda (pembrolizumab), an immunotherapy treatment for advanced melanoma.

Keytruda is one of a new generation of PD-1 therapies that block the biological pathways cancers use to disguise themselves from the immune system. It acts by making the cancer cell ‘visible’ to the immune system and thus the cell can be destroyed by the body’s natural defence mechanisms.

The drug received the FDA’s Breakthrough Therapy designation based on the significance of early study findings and unmet medical need. For the recommended 2 mg/kg dose based on data in 89 patients, the overall response rate was 24 per cent, with one complete response and 20 partial responses.

Merck is conducting ongoing phase II and III clinical studies, to provide further confirmatory evidence for Keytruda in this indication. The Breakthrough designation is designed to give earlier access to a drug that the FDA considers ‘reasonably likely’ to benefit patients.

Analysts had speculated that Bristol-Myers Squibb’s PD-1 drug Opdivo (nivolumab) might be the first of this class approved in the US, after it was approved in Japan in July.

“Keytruda embodies Merck’s unwavering commitment to pursue breakthrough science to help people who are facing the most challenging diseases,” said Merck’s CEO Kenneth C Frazier. “We are grateful to the people with advanced melanoma who participated in our trials, and the scientific and medical community for the shared effort that has led to the accelerated approval.”

Scientists based at the UK medical research charity MRC Technology (MRCT), first advanced the antibody-based treatment and carried out humanisation, an essential step in the success of the therapeutic.

MRCT CEO Dave Tapolczay, said: “We are delighted by this news and proud that MRC Technology scientists played a significant early-stage role in bringing this new cancer treatment to patients. Clinical investigators involved in trialling Keytruda have described the treatment’s potential as ‘exciting and striking’ and a ‘paradigm shift’ for cancer therapy. This is good news for cancer sufferers and represents a significant milestone in the treatment of highly invasive tumours such as advanced melanoma.”

The UK government’s Life Sciences Minister George Freeman added his praise, saying: “We are proud to see UK scientists once again playing a vital role in developing an exciting new drug, which has such potential for impact on patients’ lives. This success serves to highlight the importance of continued support for the life science sector in the UK.”

An application for European (EMA) approval for Keytruda was made in June.

The therapy holds great potential for treatment of an array of different cancers, and by the end of 2014 it will be in 24 clinical trials for 30 tumour types, involving an estimated 6,000 patients.

Links

BMS and Ono to collaborate on immunotherapy combinations in Japan

Merck collaborates on novel prostate cancer treatments

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