STORM Therapeutics Advances First-in-Class METTL3 Inhibitor to Phase 2 Sarcoma Trial

Secures $56 Million Series C Financing to Support Development of Novel Cancer Therapy

Apr. 16, 2026 at 8:20am

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A ghostly, translucent X-ray photograph revealing the intricate internal structure of a human bone, with glowing lines and shapes conceptually representing the molecular processes involved in sarcoma development that are targeted by a novel cancer therapy.A new phase of clinical trials for an innovative sarcoma therapy aims to reprogram the underlying cellular mechanisms driving this rare and aggressive form of cancer.Today in Miami

STORM Therapeutics, a clinical-stage biotech company targeting RNA modifications, announced a successful $56 million Series C financing to advance its first-in-class METTL3 inhibitor, STC-15, into a Phase 2 monotherapy study for select sarcoma indications. STC-15 has demonstrated durable tumor regression across multiple sarcoma subtypes in prior Phase 1 trials, highlighting its potential to reprogram malignant progenitor cells by modulating mRNA methylation.

Why it matters

Sarcomas are a rare and aggressive form of cancer that arise in bone or soft tissues, with limited treatment options. STC-15's novel mechanism of action targets the underlying driver of sarcoma development, the aberrant regulation of cell differentiation processes, offering hope for new therapeutic avenues for patients with this unmet medical need.

The details

The Phase 2 trial is designed to support a potential accelerated regulatory approval pathway for STC-15 and establish a foundation for subsequent clinical development across additional oncology indications. STC-15 inhibits METTL3, an RNA-modifying enzyme involved in the regulation of cancer stem cell differentiation, a critical process in the development of sarcomas and other malignancies.

  • The first patient has now been successfully dosed in the Phase 2 monotherapy study.
  • Results from the prior Phase 1 monotherapy study will be presented at an upcoming medical conference in 2026.

The players

STORM Therapeutics

A clinical-stage biotechnology company targeting RNA modifications to reprogram malignant cells and treat disease.

STC-15

STORM's lead candidate, a first-in-class, oral small-molecule inhibitor of METTL3 that has demonstrated durable tumor regression across multiple sarcoma subtypes in prior Phase 1 trials.

Jerry McMahon

Chief Executive Officer of STORM Therapeutics.

Jonathan Trent

Physician at the University of Miami, Sylvester Comprehensive Cancer Center.

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What they’re saying

“Advancing our first‑in‑class METTL3 inhibitor, STC-15, into Phase 2 clinical development marks a pivotal breakthrough in tackling cancers characterized by aberrant cell differentiation. This milestone highlights our scientific innovation and the potential to create new therapeutic options for patients with substantial unmet needs.”

— Jerry McMahon, Chief Executive Officer of STORM Therapeutics

“The launch of the Phase 2 trial for STC-15 represents a significant advancement in the treatment landscape for sarcoma and other tumors driven by METTL3. STC-15's novel mechanism of action targets sarcomas at their vulnerability, reprogramming malignant cells toward cell cycle arrest and apoptosis. We are hopeful that this research will yield meaningful insights and, ultimately, new therapeutic avenues for patients with pressing unmet needs.”

— Jonathan Trent, Physician at the University of Miami, Sylvester Comprehensive Cancer Center

What’s next

The Phase 2 trial will assess the anti-tumor effects of inhibiting mRNA methylation in sarcomas, with the goal of supporting a potential accelerated regulatory approval pathway for STC-15.

The takeaway

STORM's development of STC-15, a first-in-class METTL3 inhibitor, represents a significant advancement in the treatment of sarcomas and other cancers driven by aberrant cell differentiation processes. The successful Phase 2 trial initiation and continued progress of this novel therapy offer hope for patients with limited treatment options.