Privately held Mentari Therapeutics plans to hit the public markets through a reverse merger with InMed Pharmaceuticals, creating a combined company focused on antibody drugs that can prevent migraines.
The deal, announced Tuesday, has already received approval from the boards of both parties and is expected to close in the back half of this year. Terms hold that InMed shareholders would own roughly 1.5% of the combined company, which is slated to have a pro forma equity value of about $421 million. Baked into that value is a concurrent private placement that will result in gross proceeds of approximately $290 million.
The private placement was led by Fairmount, a Pennsylvania-based investment firm, and saw participation from more than a dozen other backers, including Blackstone Multi-Asset Investing, Wellington Management, a16z Bio + Health and Perceptive Advisors. The haul should support the combined company — which will operate under the Mentari name — through 2028. By that time, Mentari anticipates having clinical data for its two lead programs.
Those programs were discovered at Paragon Therapeutics, a prolific “hub-and-spoke” biotech incubator that has spun out a handful of companies developing drugs for cancer, immune system disorders and neurological diseases. With Mentari, Paragon is exploring whether migraines can be avoided through the inhibition of a nervous system protein known as PACAP. This protein regulates stress and, when triggered, causes pain-sensing nerves to fire and blood vessels in the head to drastically widen.
PACAP is a target for at least a couple other drugmakers. Slate Medicines, a startup co-founded by RA Capital Management, recently secured $130 million from a group of blue-chip biotech investors to push forward an experimental medicine in-licensed from China’s DartsBio Pharmaceuticals.
Farther along is Lundbeck, which earlier this year announced that a drug it acquired through the $2 billion buyout of Alder BioPharmaceuticals had succeeded as a migraine prevention treatment in a second mid-stage study. The Danish company now intends to speak with regulators about the design of a late-stage program.
The Alder acquisition also handed Lundbeck “eptinezumab,” an antibody drug that, in 2020, received marketing approval for migraine prevention. Sold as Vyepti, it was part of an emerging class of therapies that work by blocking another nervous system protein, “CGRP,” that sets off pain signals and inflammation.
By taking aim at PACAP, Mentari and others hope to offer relief to patients whose migraines aren’t adequately controlled. In a statement, InMed cited statistics showing that close to half of the patients on currently available treatments don’t experience a 50% decrease in monthly migraine days, and fewer than one-third report a 75% reduction.
Mentari’s main programs are codenamed MT-001 and MT-002. The former targets PACAP alone, and is on track to have Phase 2 “proof-of-concept” data in 2028. The latter is a “bispecific” antibody meant to hit both PACAP and CGRP. Phase 1 data from a study of healthy volunteers should come in 2027.
The Mentari deal “represents an excellent opportunity for InMed shareholders to participate in the development of an exciting new drug pipeline with significant therapeutic and commercial potential," said InMed CEO Eric Adams in the company’s, in that Tuesday statement.
Adams added that Mentari's lead programs “have tremendous potential to expand and reshape the migraine treatment and prevention market.”
InMed was built around small molecule drugs that amplify a couple types of “cannabinoid receptors” — proteins that can adjust mood, memory, pain perception and immune system responses. The company’s shares cratered between mid-2021 and early 2023. Over most of this year, InMed has been a penny stock.
Once finalized, the new Mentari will trade on the Nasdaq under a fresh ticker symbol. The existing Mentari board will oversee the combined company, with Julie Bruno, a growth partner at Fairmount, serving as chair. Bruno will be joined by Michelle Pernice, an operating partner at Fairmount, and Laura Sandler, the chief operating officer at another Paragon company, Oruka Therapeutics.
