John Mulligan Bonum Therapeutics
John Mulligan, PhD, founder and CEO at Bonum Therapeutics.

Bonum Therapeutics, a biopharmaceutical startup that uses allosteric control to develop conditionally active and less toxic medications, has announced a $93-million Series A funding round.

“Allosteric regulation is used everywhere in nature, but it’s never really been applied to therapeutics before,” John Mulligan, PhD, CEO and founder of Bonum Therapeutics, told GEN Edge. “We’ve implemented allosteric regulation using antibodies and cytokines—standard components with different behaviors where there’s a change in the confirmation of the molecule.”

Summum Bonum (The highest good)

Bonum spun off from Good Therapeutics, which was acquired by Roche in August 2022 for a $250-million upfront payment with future milestone payments. The investor syndicate that backed Good Therapeutics—Rivervest Venture Partners, Roche Venture Fund, Digitalis Ventures, 3×5 Partners, and Codon Capital—plus a new investor, Vivo Capital, backed the Series A funding round. With the funding, Vivo Capital’s Mitchell Mutz, PhD, will become a member of the Bonum board of directors.

Since its foundation in 2016, Good Therapeutics has raised over $30 million in venture financing to go from an idea on paper to the deal with Roche. In the acquisition, the Swiss pharma essentially gained a small company with one program for an IL-2 compound conditionally activated by PD-1.

“With Roche, we had a very sophisticated potential buyer who could evaluate the value of the program at a very early stage,” Mulligan told GEN Edge. “The whole team and staff moved from Good Therapeutics over to Bonum Therapeutics—and I say moved entirely metaphorically since we stayed in the same lab and just sold the program.”

This round, Bonum (which means “good” in Latin) raised more than $90 million with the aim to take a single program out of a half-dozen active programs into Phase I and collect a year’s worth of data. Prior to the acquisition by Roche, Good Therapeutics had been working on several allosterically-regulated cytokines—IL-12, IFN-alpha, and TGF-beta—when the PD-1/IL-2 program provided promising data. “Most of our effort focused on getting that to the point where [the PD-1/IL-2 program] was ready to go into the clinic,” Mulligan told GEN Edge. “But in the background, we had been perking along with some other projects: PDL-1 regulated IFN-alpha, PD-1 regulated IL-12, and the possibility of using extracellular ATP to regulate cytokines so they’d be on in tumors but off in most of the rest of the body.”

To oncology and beyond

Mulligan isn’t naive to the notion that Bonum is joining a highly competitive immuno-oncology space. Bonum’s CEO and founder said that by coming in with this different and new capability of turning things on and off, Bonum can compete in a space that’s already very crowded.

“We’ve got an experienced team, a technology that we’ve shown works and has been validated externally by the Roche purchase, and many exciting programs,” Mulligan said. “We showed that with PD-1/IL-2 in immuno-oncology, where the two most crowded areas are PD-1 checkpoint and IL-2 in terms of the number of companies and projects. We need to show human proof-of-concept to sell these programs for what we think they’re worth. If we can show efficacy without toxicology signals, there’ll be a lot of interest.”

In addition to the internal efforts on immuno-oncology and cytokines, Mulligan says that Bonum is interested in collaborations with other companies. “We want partners that can come in with some biological and clinical expertise and help choose a sensor-therapeutic pair that makes sense in whatever field they’re expert in—whether it’s in auto-immunity, metabolic disease, other aspects of oncology, and, even, pain,” said Mulligan. “It’s a chance to impact other areas of medicine where we can do a little bit of work making a regulated molecule.”

Mulligan sees Bonum’s technology as broadly applicable outside of the area of cytokines. “We can sense anything that an antibody can bind, whether a protein or small molecule,” Mulligan said. “And we can regulate basically anything you can encode as a protein, such as a cytokine, enzyme, or another antibody. It has very broad potential utility.”