Parabilis Medicines closed a $305 million Series F to advance its Helicon peptide platform and lead candidate zolucatetide into later‑stage testing for oncology. The round, led by RA Capital, Fidelity and Janus Henderson, more than doubled Parabilis’ valuation from its 2024 financing and follows encouraging early human data from its Phase 1/2 program. Parabilis’ Helicon technology engineers constrained, cell‑penetrant peptides to reach intracellular “undruggable” surfaces such as beta‑catenin; management says zolucatetide has shown compelling preliminary efficacy and tolerability signals. The company plans to use proceeds to accelerate trials and commercial readiness, and investors view the round as a bet on peptide modalities that can access intracellular targets. The financing arrives amid renewed VC momentum for biotech platforms that address historically intractable targets; Parabilis’ haul positions it to push the lead program into registrational planning and strengthens its pathway toward an eventual IPO.