U.K. biotech C4XD leaps on $294M addiction drug deal with Indivior

Shares in U.K. biotech C4X Discovery almost doubled today after Reckitt Benkiser spinout Indivior agreed to a $294 million deal for a drug candidate to treat addiction.

Indivior is paying $10 million upfront for global rights to C4X3256, an orexin-1 (OX1) receptor antagonist in preclinical development that C4XD said has potential in just about any form of addiction—including tobacco, opioid analgesic and alcohol—as it targets the feeling of craving itself. Current drug therapies are more specific, focus on either substituting the addictive substance itself or blocking its effects.

The deal with Indivior is something of a coup for CX4D. Its new partner is a big player in opioid addiction with its well-established Suboxone (buprenorphine and naloxone) film product—which has a market share above 50%—and has just bagged U.S. approval for new once-monthly injectable Sublocade (buprenorphine).

C4XD said that the neurotransmitter orexin—and specifically the OX1 receptor—has been studied for its role in the craving and reward pathways in the brain for some time. However, progress in developing drugs that can interact with it and reduce cravings has been held back by a lack of selectivity among drug candidates.

The company has been working with German biotech Evotec since 2015 on the orexin project, focusing on developing drugs for addiction that are highly specific to OX1 and with minimal off-target effects on OX2, which seems to be involved in wakefulness and is also being targeted in the treatment of insomnia. CX3256 has been designed to tackle craving by causing drowsiness, and the deal with Indivior covers all of the U.K. biotech’s compounds in the same patent family across multiple indications.

C4XD CEO Clive Dix, Ph.D., said: “Today’s licensing agreement with Indivior, a world-leader in developing and commercialising treatments for addiction, highlights the ability of our drug discovery engine to generate best-in-class small-molecule candidates in high value therapeutic areas.”

“This agreement will allow us to accelerate the development of our portfolio to similar successful commercial arrangements and validates our business model,” he added.

Opioid abuse has become such an acute problem in the U.S. that President Trump signed an executive order last year to elevate the situation to the status of a public health emergency.

Indivior’s position in the addiction market is under threat, however, as main revenue-earner Suboxone is facing the threat of generic competition in the U.S. after a patent infringement ruling, and is also seeing its market share trimmed back with some healthcare payers encouraging prescribing of generic, tablet-based buprenorphine and naloxone drugs.

The company needs Sublocade to gather pace quickly while it brings additional drugs through the pipeline, including RBP-7000, a once-monthly risperidone injection for schizophrenia which is heading for an FDA verdict in July. It has previously predicted Sublocade sales could eventually clear the $1 billion mark.