STORM Therapeutics Raises $56M Series C for METTL3 Inhibitor
STORM Therapeutics, a Cambridge, UK-based clinical-stage biotech developing small-molecule inhibitors of RNA-modifying enzymes for oncology, raised $56 million in Series C funding from existing investors including Pfizer Ventures and M Ventures. The lead asset, STC-15, is the first-in-class METTL3 inhibitor advancing cellular reprogramming to target cancer stem cells. The capital supports the ongoing Phase 2 monotherapy trial in sarcomas, where the first patient has been dosed.
Epigenetics Funding Accelerates in 2026
The raise aligns with renewed investor interest in epigenetics, as Epigenic Therapeutics completed a $60M Series B in September 2025 to advance clinical epigenetic medicines. Accent Therapeutics, a direct rival targeting RNA regulators, plans to present preclinical data on its lead METTL3-related program at AACR 2026. STORM differentiates with STC-15 already in Phase 2 for sarcomas, building on Phase 1 data showing durable tumor regressions.
Sarcomas Lack Effective Therapies
Sarcomas represent an unmet need, with patients often refractory to standard treatments like immune checkpoint inhibitors. Current therapies fail to address cancer stem cell differentiation driven by RNA modifications like m6A. STORM targets METTL3, an RNA-modifying enzyme overexpressed in sarcomas such as dedifferentiated liposarcoma and leiomyosarcoma.
First-in-Class METTL3 Inhibition
STC-15 inhibits METTL3 to reprogram cancer cells, achieving durable responses in Phase 1 across sarcoma subtypes. Unlike DNA-focused epigenetics, STORM's epitranscriptomics approach modulates RNA directly for oral, brain-penetrant potential. The company pioneered the first RME inhibitor into human trials, validated by partnerships with AlidaBio for biomarker discovery and Coherus for combo with LOQTORZI in solid tumors.
Pipeline Expansion Underway
Beyond STC-15, STORM advances STM11315, an oral DHX9 helicase inhibitor with preclinical efficacy in genomically unstable cancers. Recent data presentations at SITC 2024 and planned for AACR-NCI-EORTC 2025 underscore platform strength. Phase 1b/2 combos target NSCLC, HNSCC, melanoma, and endometrial cancers.
Repeat Investors Signal Confidence
Following a $30M Series A in 2022 from the same backers, this extension reflects conviction in STORM's clinical momentum. Pfizer Ventures' continued support validates the RNA epigenetics modality amid Big Pharma interest in novel oncology targets.
Epigenetics Market Scales Rapidly
The global epigenetics market stands at $15.62B in 2026, projected to reach $35.84B by 2031 at 14.8% CAGR per The Business Research Company. Trends favor epitranscriptomics, with RNA-modifying enzymes emerging as druggable beyond traditional histone modifiers.
Clinical Leadership Bolstered
Serial founder Sir Tony Kouzarides, knighted in 2024 and co-founder of publicly traded Abcam plc, brings epigenetics expertise from Cambridge's Gurdon Institute. New CEO Jerry McMahon oversaw Harpoon's IPO and Sutent approval, while CDO Eric Martin and CMO Atif Abbas add oncology development pedigree.
Phase 2 Momentum Builds
With STC-15's first Phase 2 patient dosed and data slated for 2026 conferences, STORM eyes accelerated approval in sarcomas. Ongoing combos and STM11315 preclinical advancement position the firm for broader oncology expansion.
As CEO Jerry McMahon noted:
"Our clinical data has demonstrated that STC-15 can achieve durable responses for patients who are refractory to immune checkpoint inhibitors."
Sources for this claim include company press releases and news coverage.