Merck drug shines at ASCO

Pharmafile is attending and covering this year's event in Chicago

Merck has shown off one of its investigative cancer drug’s impressive results in advanced head and neck cancer at ASCO 2014 as part of a Phase 1b study.

Around a fifth of patients – most of whom had received two or more prior lines of therapy - taking pembrolizumab (MK-3475) as monotherapy responded to the treatment.

It is part of a new class of medicines known as PD-1 inhibitors which use the body itself to attack cancer, targeting the protein that cancers deploy to evade natural immune defences. 

Merck says it is putting pembrolizumab up against the current standard of care in this therapy area in the third quarter of the year.

The manufacturer has high hopes for the drug, investigating it in around 30 tumour types. Last year it was impressive in a melanoma study, keeping more than four out of five melanoma patients alive for a year during the study, including some who were very late-stage and had tried all other medical options.

The research found 41% responded to treatment and 9% showed evidence of the tumour disappearing – and while the improvement emerged within three months for most patients, several responded more than six months later.

In head and neck cancer the drug has also shown its worth, with early data showing a best overall response rate of 20 per cent.

“We continue to observe robust signals of anti-tumour activity in response to pembrolizumab monotherapy across multiple tumour types and lines of therapy, including these data in head and neck cancer,” says Roy Baynes, senior VP, global clinical development, Merck Research Laboratories.

The data comes from a cohort of KEYNOTE-012, which evaluated pembrolizumab monotherapy10 mg/kg every two weeks in 56 patients whose tumours were assessed as positive for PD-L1 expression using Merck’s own immunohistochemistry (IHC) trial assay.

The most common adverse events were fatigue, pruritus, rash and nausea – and an additional 110 patients are planned to be enrolled in KEYNOTE-012.

“The results for pembrolizumab seem particularly interesting,” says Ana Nicholls, healthcare analyst at The Economist Intelligence Unit.

“Merck has already gathered enough evidence to file pembrolizumab for FDA approval for melanoma, but there are also high hopes that the drug could be used to treat lung cancer too. Given the number of people still dying from this disease, that would be extremely exciting,” she adds.

Adam Hill