Parabilis Medicines closed a $305 million Series F to accelerate development of its Helicon peptide platform and lead candidate zolucatetide, which targets intracellular beta‑catenin pathways. The financing, led by RA Capital, Fidelity and Janus Henderson, represents one of the largest early-year biotech raises and signals investor conviction in modalities aimed at conventionally undruggable intracellular targets. Company executives said the funds will support expansion of the Phase 1/2 program and prepare late-stage development activities. Parabilis’ Helicon technology, rooted in helix-shaped peptides designed to penetrate cells, has shown encouraging early clinical signals per the company’s disclosures and commentary from investors. The round arrives amid a broader rebound in biotech capital markets where high-value platform bets are again attracting large syndicates. Parabilis’ financing also re-energizes discussion about peptide-based intracellular targeting as a competitive route for oncology drug development.