Synthekine scores major $108M B round to secure set of trials in 12 months

Synthekine scaled another rung on its quest to becoming a “category-defining cytokine company” with a $107.5 million series B A the preclinical company joins a crop of biotechs breaking into the cytokine space.

Menlo Park, California-based Synthekine secured the oversubscribed round en route to bringing two lead candidates into the clinic over the coming 12 months. Deerfield Management and Janus Henderson co-led the financing along with participation from RA Capital Management, Rock Springs Capital, Omega Funds and about half a dozen other investors.

Synthekine plans to file an IND for STK-012 later this year and follow up with another filing for SDK-009 in early 2022, CEO Debanjan Ray said in an interview.

STK-012 is a partial interleukin-2 agonist that is meant to activate T cells that recognize tumor antigens. In April the company presented data showing anti-tumor activity while avoiding toxicities that have negatively impacted IL-2 therapeutics in the past. STK-009 is an orthogonal IL-2 ligand targeting activation of CAR-T cells and other adoptive cell therapies.

The company started two years ago and publicly launched in September 2020 with $82 million in funding. Synthekine’s work comes from the lab of K. Christopher Garcia, Ph.D., at Stanford University, through an initial in-license of four programs and followed up in recent months with three additional licenses for cytokine partial agonists.  

“Chris is one of the foremost structural biologists in the world and has really focused on the cytokine space for the last decade or so. He’s resolved the structure function relationship of about 16 different cytokines,” Ray said. “Structural information around cytokines is really important because one of the challenges of cytokines is they're known as what's [called] pleiotropic, so they have various effects on various cell types in various contexts.”

This has led Synthekine to focus on building more selective therapeutics, Ray said. Along with the expertise of Garcia’s lab, Snythekine also boosted its management with a new chief medical officer to help lead the charge.

Naiyer Rizvi, M.D., formerly director of thoracic oncology at Columbia University Medical Center, joined last month and is tasked with getting candidates through the clinic. Rizvi’s research has led to FDA approved immunotherapies like Opdivo and Keytruda. Bristol-Myers Squibb’s Opdivo landed at No. 8 on Fierce Pharma’s top 20 drug sales of 2020 with $7.92 billion, and Merck’s Keytruda generated a whopping worldwide total of $14.4 billion.

With the funding, which Ray said will provide enough runway to produce clinical data on at least two lead programs, Synthekine will consider forming partnerships. Ray’s resume is built on partnerships. “That’s mainly what my career in biotech has been,” he said. Prior to Synthekine, the executive was chief financial officer and head of corporate development at CytomX Therapeutics and held business development roles prior to that at Itero and Portola.

“We’ve got the opportunity, given the capital we’ve raised and the expertise we have, to be very selective about partnerships. I think that’s an important next step for the company, and certainly we’re talking to pharma about various partnership opportunities,” Ray said, noting there is “nothing imminent.”

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Once it’s time to formalize partnerships, Ray said Synthekine will seek out Big Pharmas with extensive knowledge of cytokine biology. Synthekine is working on both the pro- and anti-inflammatory sides, so cancer and autoimmune disease partners would be of interest, as well, the CEO said. Sanofi is a notable Big Pharma in the space with its $2.5 billion purchase of Synthorx in 2019, which appears to be paying off with promising early phase 1 data released in April.

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Synthekine is one of many cytokine-focused biotechs that Big Pharma will likely pay close attention to in the years to come. Werewolf Therapeutics had a howling debut on the Nasdaq in April after a $72 million private financing just three months prior. Also this spring, Asher Bio launched with $55 million in funding.