When Hanne Callewaert walked away from KU Leuven's storied Rega Institute in 2022 to launch AstriVax Therapeutics, she did so with a thesis that sounded almost uncomfortably broad: end virus-driven cancer. Perhaps more surprising than the ambition was what came next—a €30 million seed round, the largest for a KU Leuven spin-out as of its 2022 announcement, and a roster of European investors that read like a who's who of life sciences capital.
The August 2022 financing, co-led by V-Bio Ventures and Fund+, pulled in Flanders Future TechFund (through PMV), Thuja Capital, Ackermans & van Haaren, Mérieux Equity Partners via OMX Europe Venture Fund, BNP Paribas Fortis Private Equity, and the university's own Gemma Frisius Fund. By any measure, it was a statement—both about the platform and the pedigree of the science behind it.
AstriVax's central wager is that a modified yellow fever vaccine can train the immune system to hunt down cancers sparked by viral infections. It's an old vector pressed into new service, designed to elicit what immunologists call "durable antigen-specific T-cell responses." Translation: the body's own killers, trained to recognize and destroy cancer cells bearing viral fingerprints.
The market opportunity, at least on paper, is sizable. Global health data pegs infections—HPV, hepatitis B, H. pylori, and others—as responsible for roughly one in ten new cancer cases worldwide, trailing only smoking. That 10.2% figure, drawn from 2022 data published by the International Agency for Research on Cancer, represents millions of patients annually. Whether AstriVax's Launch-iT platform can deliver on that scale remains an open clinical question.
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From Leuven to the Clinic
Callewaert, who holds a PhD and serves as CEO, co-founded the company with Professor Johan Neyts and Dr. Kai Dallmeier, both veterans of the Rega Institute's virology programs. The trio set up shop in Heverlee, just outside Leuven, and moved quickly. By June 2024, AstriVax had dosed its first human participants in SAFYR, a Phase I trial testing prophylactic vaccines for yellow fever and rabies at sites in Ghent and Antwerp. The study has since been completed.
A second program followed a year later. In June 2025, AstriVax launched RUBY, a Phase I study of AVX70371, a therapeutic vaccine aimed at chronic hepatitis B. The trial—registered under NCT06989788—is evaluating safety, tolerability, and immune response in healthy volunteers, with plans noted in Belgian regulatory filings to include a cohort of patients with active HBV infections.
The company's oncology focus centers on HPV16, the most common high-risk strain of human papillomavirus and the culprit behind a majority of cervical, throat, and other mucosal cancers. AstriVax says its initial target population will be women with persistent HPV16 infections that have not yet progressed to high-grade lesions—a prevention play, in effect, rather than treatment of established disease. Whether that strategy finds favor with regulators and payers is unclear; the bar for intervening in pre-cancerous states has historically been high.
Beyond oncology, the company has hinted at applications in autoimmune diseases where viral triggers are suspected, though details remain sparse.
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A Crowded Field, Different Mechanics
AstriVax is hardly alone in chasing therapeutic cancer vaccines. BioNTech's BNT113, an mRNA construct targeting HPV16-positive head and neck cancers, received FDA Fast Track designation in January 2026 and is being evaluated in pivotal studies. PDS Biotech and Norway's Nykode are advancing late-stage programs of their own, using peptide and DNA platforms, respectively.
The Launch-iT approach stands apart mechanistically—it's built on a yellow fever 17D viral vector, a live attenuated strain with decades of safety data in the prophylactic vaccine setting. Whether that translates to efficacy against entrenched viral cancers is the billion-dollar question. All these platforms share a common ambition: priming robust cytotoxic T-cell armies against viral oncoproteins like HPV's E6 and E7, the molecular hijackers that drive malignant transformation.
Some industry observers have questioned whether the yellow fever backbone offers enough differentiation, given the capital and momentum behind mRNA candidates. Others point to AstriVax's emphasis on scalable, tech-transfer-ready manufacturing—a potential advantage in regions without reliable cold-chain logistics, though also a tacit acknowledgment that the platform may ultimately find its home in partnership deals rather than as a standalone therapeutic empire.
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The Money Trail
Since the 2022 seed round—pegged at roughly $29.8 million using that year's exchange rates—AstriVax has layered on an additional €5.5 million in non-dilutive funding, primarily through grants from VLAIO, the Flemish innovation agency. A €2.5 million award arrived in May 2023, followed by a €3 million grant in December of that year earmarked for the hepatitis B program. The company disclosed these figures at the January 2025 Biotech Showcase, a San Francisco gathering that has become something of a ritual for European biotechs looking to court U.S. capital.
Ackermans & van Haaren, the Belgian investment firm, holds approximately 7.7% of AstriVax according to investor materials—a stake that underscores the local roots of the syndicate, even as the science aims for global impact.
The company's LinkedIn profile suggests a headcount in the 11-to-50 range, a lean posture typical of European biotechs navigating the gap between academic spin-out and commercial-stage operation. Whether AstriVax will need to raise again before reaching data readouts—or whether the VLAIO grants and existing runway buy enough time—is a calculus the company has not publicly addressed.
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What Comes Next
AstriVax has delivered on its 2022 promise to advance the platform into human trials, hitting that milestone with two studies now underway or completed. The SAFYR data, assuming it's clean, should provide validation that the yellow fever vector can be safely deployed and does what it's supposed to do immunologically. The RUBY results will tell a similar story for hepatitis B, though any signal of functional cure—the holy grail in chronic HBV—remains speculative at this stage.
The oncology program, the one that attracted the big checks, is still in the wings. Company timelines suggest an HPV16 asset could enter the clinic in the near term, though no formal trial registrations have surfaced yet. That's where the real test begins—not just whether the vaccine can generate T cells, but whether those cells can clear persistent infections or shrink tumors in meaningful numbers.
For now, AstriVax occupies an intriguing middle ground: validated enough to have raised serious capital and attracted heavyweight investors, but early enough that the platform's ultimate viability remains an open question. In an era when therapeutic cancer vaccines have become fashionable again—thanks in no small part to the mRNA revolution—it's a narrative that will play out over the next several years, one trial readout at a time.
