Strand Therapeutics Secures $153M in Series B Funding to Advance Programmable mRNA Pipeline

BOSTON-Aug 07, 2025-(BUSINESS WIRE)-Strand Therapeutics, an mRNA-based therapeutics company, has raised $153 million in Series B funding, bringing its total raised to over $250 million. The funding round was led by Kinnevik and included new investors such as Regeneron Ventures, Amgen Ventures, and Eli Lilly and Company. The capital will be used to advance Strand’s pipeline, which is focused on programmable mRNA therapies.

Advancing the Pipeline

Strand’s lead candidate, STX-001, is a programmable mRNA therapy designed to express the cytokine interleukin-12 (IL-12) directly from within the tumor. The company recently announced promising initial Phase 1 clinical data for STX-001 in patients with advanced solid tumors, showing multiple positive responses and a favorable safety profile. Unlike traditional mRNA therapies, STX-001 uses self-replicating mRNA for localized and durable therapeutic activity.

The company also presented preclinical data for STX-003, a new systemically administrable mRNA therapy with tumor-targeting capabilities. Data from the 2025 AACR and ASGCT annual meetings showed the therapy’s potential to target IL-12 expression to tumors following systemic administration, creating an effective and well-tolerated anti-tumor therapy.

The Technology Behind the Therapies

Strand’s proprietary platform combines next-generation mRNA modalities, such as self-replicating and circular RNA, with genetically programmed logic circuits. This allows for precise, controlled therapeutic payload delivery directly into specific cells and tissues. The company believes this approach has the potential to transform the treatment of cancer and other serious diseases by creating targeted, scalable, and accessible therapies.

According to CEO Jake Becraft, the initial Phase 1 data for STX-001 provides strong clinical validation for the platform’s capabilities, demonstrating systemic immune activation and anti-tumor responses. Christian Scherrer of Kinnevik stated that Strand’s early clinical data is “outstanding,” and that its systemic delivery capability could “reshape how we treat disease, starting with cancer.”