Co. to Use Body’s Innate Immune System Against Cancer

Many cancer drugs boost the body’s ability recognize and defend against invaders, falling under the banner of adaptive immunity. But often cancer cells evade this system, meaning a patient may not respond to treatment, or relapse.

Primmune Therapeutics is focusing another arm of the immune system — the innate part, which acts as the body’s first line of defense. Against this backdrop, the San Diego biotech has raised $7 million in a seed round.

“We’re turning on the body’s ability to go fight and kill tumors,” said CEO Charlie McDermott.

Primmune envisions its drugs being used in combination with treatments targeting adaptive immunity, potentially in a variety of cancers.

But the biotech still has a ways to go. Primmune will soon select a drug candidate, and then, assuming the regulatory greenlight, the company is a year or so away from clinical testing in humans.

To get approval most drugs must clear three phases of clinical trials.

Most Challenging Fundraise Yet

McDermott, who has raised hundreds of millions of dollars in the life sciences industry, said this seed round was the most challenging fundraise yet.

He said investors were eventually swayed by new ways of thinking about cancer — and the renewed promise of honing in on the innate immune system.

Key to this system are a family of “toll-like receptors,” with Primmune taking aim at the seventh of 10, or TLR7.

“We had to carry this program incredibly far down the road before people would start investing,” McDermott said. “Now everything is starting to turn our way.”

Besides cancer, Primmune wants to treat acute viral diseases. Plans call for clinical trials to begin in this area in 18 months.

Founded in 2017, McDermott said the company got off the ground with financial — and moral — support from a number of biotech executives in town.

“If this was not done in San Diego, no way it would have happened. It’s truly a hometown kind of story,” he said, adding the region has a tight-knit biotech community.

Impact Biomedicines Connection

McDermott was previously the president and chief business officer of Impact Biomedicines. The San Diego biotech resurrected a cancer drug and sold to Celgene for up to $7 billion in 2018.

After that, McDermott staked out opportunities in the oncology space, but nothing excited him — until Primmune. Initially he invested in the company, and then went on to helm it.

The other investors in the seed round were AM Capital, BioBrit and BioRock Ventures.

Many biotechs license their programs from research institutions, but Primmune owns its programs outright. Co-founders Stephen Webber and James Appleman created the company’s molecules from scratch.

Webber is also the executive director of medicinal chemistry at Polaris Pharmaceuticals, while Appleman is also the co-founder of eFFECTOR Therapeutics.

In conjunction with the seed financing, well-known names joined Primmune’s board: Ezra Cohen, chief of the hematology-oncology division at Moores Cancer Center; Isan Chen, the chief medical and development officer of Mirati Therapeutics; and Scott Morenstein, managing director at CAM Capital.

Like other upstart biotechs, Primmune plans to contract out a good deal of work to keep the company lean. It has four full-time employees, with near-term plans to have a dozen on the payroll.