Theriva Biologics Shifts Focus to Oncolytic Adenovirus VCN-01, Pauses GvHD Drug Development

Theriva Biologics, a Maryland-based biotechnology company, has announced a strategic shift in its research and development priorities. The company is redirecting its resources towards the development of VCN-01, an oncolytic adenovirus, while putting its graft-versus-host disease (GvHD) drug candidate on hold.

SYN-004 Development Paused

Theriva has decided to pause further development of SYN-004 (ribaxamase), a β-lactamase enzyme being studied for the prevention of acute graft-versus-host disease (aGVHD) in allogeneic hematopoietic cell transplant (HCT) patients. Despite completing a second cohort in a phase 1b/2a trial and receiving regulatory approval to proceed to a third cohort, the company cited limited cash resources as the reason for this decision.

The continuation of SYN-004's development is now contingent on securing new grant funding or finding a licensee or partner. This move reflects the company's need to prioritize its pipeline in the face of financial constraints.

VCN-01: The New Focus

Theriva is now concentrating its efforts on VCN-01, an oncolytic adenovirus with potential applications in multiple oncology indications. The drug is currently being evaluated in several early-to-mid-stage clinical trials:

1. Metastatic Pancreatic Ductal Adenocarcinoma: VCN-01 is in phase 2 trials for this indication, with key data expected in the coming months. Theriva is positioning itself to potentially move into phase 3 trials, depending on the results.

2. Refractory Retinoblastoma: The company has reported positive phase 1 data for VCN-01 in this rare pediatric cancer. Theriva is now planning to collaborate with key opinion leaders to develop a potential pivotal trial protocol for discussion with regulatory agencies.

Financial Outlook

Theriva Biologics reported a cash position of $11.6 million, which the company expects will sustain its operations until the third quarter of 2025. This financial update provides context for the company's strategic decisions and underscores the importance of focusing resources on the most promising candidates in its pipeline.

The market has responded positively to this announcement, with Theriva's shares rising more than 7% in after-hours trading following the release of its full-year financials on March 6, 2025.