
MPM-backed Werewolf, Merck-partnered Artiva make quick IPO flip while Luca Santarelli's biotech raises $127.5M
The jump from crossover rounds to biotech IPO is quicker than ever.
Just weeks after unveiling Series B rounds, MPM-backed Werewolf and Merck-partnered Artiva are spelling out plans to go public on Nasdaq. Both have penciled in the standard goal of raising $100 million.
That figure is fast becoming an unreliable placeholder, as many companies have gone on to raise a lot more. Luca Santarelli’s Swiss rare disease player VectivBio, though, stuck close to the range, bagging $127.5 million from its Nasdaq debut.
Howling Werewolf pounces

Boston-based Werewolf — which is going the extra mile and shooting for $HOWL as the ticker — outlined some of its plans to hit the clinic back in January, when CEO Dan Hicklin took the wraps off a $72 million Series B.
Using an engineering platform dubbed PREDATOR, the company has three molecules belonging to a class they dub Indukines, which comprises four components: a cytokine, an inactivation domain, a half-life extension domain and a linker that can be cleaved by proteases found in tumors. That way, they reason, the drug stays quiet throughout the body and only triggers an inflammatory effect against cancer.
The system makes use of technologies from Harpoon — a fellow MPM company — including “polypeptides and a binding moiety for conditional activation of certain polypeptides.” In addition to promising royalties and exchanging certain other patent rights, Werewolf paid a grand $500,000 upfront to Harpoon, which is building an operation around T cell engagement.
With an initial focus on IL-2 and IL-12, Werewolf is looking to begin human testing for WTX-124 and WTX-330 in 2022. The third candidate aims to conditionally activate IFN-a.
The company is so young that it’s only burned through $51.9 million to get here — less than the $56 million Series A they had launched with.
MPM claims the lion’s share of stock at 20.75%, followed by UBC Oncology Impact Fund and RA Capital, each a little more than 11%. Other investors include Taiho Ventures, Deerfield, Arkin and UPMC.
Hicklin, who also owns about 3% of shares after taking the top job in August 2019, was rewarded with a 2020 compensation package worth close to $3 million. CMO Randi Isaacs made $887,539, the bulk in option awards granted as she joined in November; CSO Cynthia Seidel-Dugan got a similar pay at $837,294.
Artiva sheds light on trans-Pacific NK cell manufacturing process

Until earlier this year, Artiva didn’t have much of a profile in biopharma land. Former Bellicum CEO Tom Farrell had assembled an NK cell therapy company, leaning heavily on a “hugely impressive” manufacturing facility belonging to Green Cross LabCell in Korea, gathered $78 million in Series A money and did the news rounds last June, then stayed largely quiet.
That changed when Merck signed a collaboration worth nearly $2 billion in milestones to pick up the off-the-shelf NK cell tech. Artiva quickly followed up with a $120 million Series B, designed to kickstart Phase I/II for its lead program in non-Hodgkin’s lymphoma.
The partnership deal, Artiva revealed in its S-1, gave GC LabCell a 28% stake in the biotech, almost double the holdings of 5AM Ventures, venBio, RA Capital and more than quadruple what Venrock has.
To make the products, the US team sources cord blood units with favorable characteristics — such as a natural high affinity variant of the receptor CD16 — from a public cord bank. Artiva then ships the material to Korea, where GC LabCell runs a newly built commercial site:
After manufacturing, the drug product is cryopreserved, shipped back to the United States and distributed to clinical trial sites where it will be thawed and administered in an out-patient setting. The process generates sufficient NK cells to treat hundreds to thousands of patients from a single cord blood unit, depending on the product and dosing regimen, and produces a consistently active NK cell product, with little donor-to-donor variability.

Artiva is gunning for a leading position in what, after many years, has recently become a booming field. Big Pharmas like Takeda and J&J are joining a slate of smaller players in exploring the potential of NK cell therapies in all their flavors. While it’s also working on CAR-NK approaches, Artiva’s first candidate is a “non-genetically modified, but optimized, cord blood-derived NK cell therapy.”
Farrell pocketed more than $1.2 million for steering the company before turning over to Fred Aslan in January.
From $810M buyout to spinoff IPO in less than 2 years
Luca Santarelli tells a straightforward story about VectivBio. After selling Therachon to Pfizer in an $810 million deal, the Roche vet immediately spun out with the new company, taking their Phase II drug apraglutide for short bowel syndrome.
The IPO was a natural next step on the heels of a mega-raise of $110 million announced last October, with the focus still squarely on executing the Phase III and laying the foundation for commercialization work.
A long-acting synthetic peptide analog of GLP-2, apraglutide remains the sole asset in the company and will be deployed in a range of rare gastrointestinal disorders outside of SBS.
Topline results for the lead indication, in SBS intestinal failure, are expected in 2023.
While VectivBio is looking to in-license or acquire additional drugs for the pipeline, the IPO proceeds are mostly going toward the core program — including a Phase II targeting a subgroup of SBS-IF patients with colon-in-continuity anatomy and proof of concept in apraglutide’s utility for gastrointestinal manifestations of graft-versus-host disease.
Santarelli has quite a bit of skin in the game, having saved 8.8% of the shares for himself. Versant and OrbiMed are the largest stockholders at around 15% each, while others — FCPI Bpifrance Innovation, Novo and Cowen — each have less than 10%.