VarmX and the EIC Accelerator: A Bleeding Antidote CSL May Buy

Millions of people take modern blood thinners that block clotting factor Xa, and when they bleed badly or need emergency surgery, doctors need a way to switch the effect off. VarmX, founded in Leiden by Pieter Reitsma, former head of thrombosis and haemostasis at Leiden University Medical Centre and co-discoverer of Factor V Leiden, is developing VMX-C001, an engineered clotting protein designed to restore coagulation in the presence of those drugs.

The European Innovation Council has backed VarmX twice: a €2.5 million grant from the June 2021 cut-off, with the EIC Fund joining a €30 million round in 2023, and a €15 million follow-on equity investment awarded in 2025. In September 2025 the Australian biotech group CSL paid $117 million upfront for an option to buy the company and agreed to fund the Phase 3 trial, which enrolled its first patient in August 2026.

Where VarmX Stands Today

On 20 August 2026 VarmX enrolled the first participant in EquilibriX-S, a randomised, controlled Phase 3 trial in more than 20 countries. It tests whether a single intravenous dose of VMX-C001 restores haemostasis during urgent surgery in patients who took an FXa inhibitor in the previous 15 hours, compared with usual care. The primary endpoint is the share of patients with good or excellent haemostatic efficacy.

The trial is paid for by CSL. Under the September 2025 agreement, CSL paid $117 million upfront to VarmX's shareholders for an exclusive option to acquire all of the company once Phase 3 data are in, with up to $388 million more on exercise and regulatory clearances and up to $1.7 billion in sales milestones. CSL also funds late-stage development, manufacturing and launch preparations; VarmX anticipates a commercial launch in 2029. The FDA granted the drug Fast Track status in 2025.

The Technology: A Clotting Factor the Drugs Cannot Block

Factor Xa inhibitors, such as apixaban and rivaroxaban, work by blocking a key clotting enzyme. VMX-C001 is an engineered version of factor X that, according to VarmX's published research, keeps its clotting activity even when those drugs are present, bypassing their effect rather than removing the drug. The company says it restores clotting quickly, which matters most in emergencies.

What the EIC Projects Promised, and What CORDIS Shows

StopBleeding, the grant project, ran from September 2022 to March 2025. Its CORDIS report is about manufacturing: new cell lines did not meet VarmX's benchmarks, so it optimised its existing one; a fed-batch process was validated as a cheaper alternative to perfusion; key purity assays were qualified; and early stability data suggested the drug "might not need to be lyophilized", which would simplify emergency use. The second award, equity only, backed the final clinical development that is now under way.

1. Scalable, cost-effective manufacturingDeliveredFed-batch process validated; assays qualified, per CORDIS.
2. Regulatory path to a pivotal trialDeliveredIND approval, FDA Fast Track, Japanese Phase 1 waiver.
3. Pivotal trialStartedEquilibriX-S enrolling since August 2026.
4. Approval and launchAheadLaunch anticipated in 2029.

What Has Happened Since the First Award

The Money

VarmX raised a €32 million Series B in 2020 and a €30 million Series B2 in May 2023, led by Sound Bioventures with the EIC Fund as a new investor. In February 2025 it announced the €15 million EIC follow-on equity award, one of five in a round the EIC called its most competitive, alongside a Series C that was then under way. The CSL upfront payment went to VarmX's shareholders, which include the EIC Fund.

Why Europe Should Care

VarmX grew from a Dutch university hospital's research and is now in a global Phase 3 trial with one of the world's largest plasma and biotech companies paying for it. If CSL exercises its option, the EU, through the EIC Fund, stands to share in the sale; if not, the drug's future depends on the trial alone.

The Verdict

VarmX has not been asked for comment for this article. It is based entirely on public records, company statements and EU project data, linked throughout.