Merck & Co has signed a deal with Quartet Medicine to advance the biotech’s investigational, first-in-class pain treatment and potentially buy the company for $575 million.

Quartet’s pipeline is focussed on novel small molecule drugs that modulate the tetrahydrobiopterin (BH4) pathway. This pathway has been implicated in a range of chronic human pain and inflammatory conditions, and the company says that 2% of patients born with low BH4 production have fewer problems with chronic pain.

Under the terms of the agreement, Quartet will receive up to $20 million from Merck, split equally across an upfront payment and “an undisclosed future development milestone”. This will be used to advance Quartet’s lead programme through Phase 2a trials. 

In return, Merck will get an exclusive option to purchase Quartet. If it exercises this option, the total cost of purchase along with potential development, regulatory and sales milestones could be up to $575 million in.

“Merck is an ideal partner to help advance development of our potential first-in-class therapy for chronic pain,” said Kevin Pojasek, Quartet’s president and chief executive officer. “This agreement provides a mutually beneficial collaboration framework, while providing us significant non-dilutive research and development funding to advance our program through human proof-of-concept.”

Bruce Booth, chairman of Quartet, added: “Attracting a top-tier partner like Merck provides additional validation to the importance of BH4 in regulating chronic disease, as well as the progress we’ve made at Quartet over the last year. 

“The team has done a tremendous job building a compelling preclinical data set around new drug candidates that modulate BH4. We look forward to collaborating with Merck as the Quartet pipeline continues to mature.”