STORM Therapeutics Doses First Patient in Phase 2 Sarcoma Trial of STC-15

Secures $56 Million Series C Financing to Advance First-in-Class METTL3 Inhibitor

Apr. 16, 2026 at 8:54am

Got story updates? Submit your updates here. ›

A glowing, neon outline of a human skeleton in shades of blue, purple, and pink against a dark background, conceptually representing the internal cellular mechanisms targeted by a new cancer therapy.A novel METTL3 inhibitor targets the cellular mechanisms driving sarcoma, offering hope for patients with this rare and difficult-to-treat cancer.Today in Miami

STORM Therapeutics, a clinical-stage biotechnology company targeting RNA modifications, announced a successful $56 million Series C financing. The proceeds will support the advancement of STC-15, a first-in-class, oral small-molecule inhibitor of METTL3, including funding the company's Phase 2 monotherapy study in selected sarcoma indications, in which the first patient has now been successfully dosed.

Why it matters

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. In a Phase 1 monotherapy study, STC-15 demonstrated durable tumor regression across multiple sarcoma subtypes, underscoring its potential to target and reprogram progenitor cells that transform into cancer cells.

The details

The Phase 2 trial will assess the anti-tumor effects of inhibiting mRNA methylation in sarcomas, a form of cancer that arises in bone or soft tissues. Sarcomas depend on METTL3-driven methylation for growth and survival, and the absence of driver mutations or immunogenic features makes them difficult to treat with standard therapies.

  • The first patient in the Phase 2 sarcoma trial of STC-15 has now been successfully dosed.
  • The results from the Phase 1 monotherapy study of STC-15 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

A first-in-class, oral small-molecule inhibitor of METTL3 that is being assessed as a monotherapy in a Phase 2 study for select sarcomas.

Jerry McMahon

Chief Executive Officer of STORM Therapeutics.

Jonathan Trent, MD

From the University of Miami, Sylvester Comprehensive Cancer Center, who commented on the significance of the Phase 2 trial for STC-15.

M Ventures, Pfizer Ventures, Taiho Ventures LLC, IP Group plc, the UTokyo Innovation Platform Co., Ltd. (UTokyo IPC), and Fast Track Initiative (FTI)

The existing investors who funded the $56 million Series C financing.

Got photos? Submit your photos here. ›

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, MD, University of Miami, Sylvester Comprehensive Cancer Center

What’s next

The Phase 2 trial of STC-15 in select sarcoma indications is designed to support a potential accelerated regulatory approval pathway and establish a foundation for subsequent clinical development across additional oncology indications.

The takeaway

STORM Therapeutics' advancement of its first-in-class METTL3 inhibitor, STC-15, into Phase 2 clinical trials for sarcoma represents a significant milestone in the company's efforts to develop novel cancer therapies that target RNA modifications to reprogram malignant cells. The promising results from the Phase 1 study and the $56 million Series C financing underscore the potential of this approach to address critical unmet needs in sarcoma and other hard-to-treat cancers.