GlobeNewswire·Nov 2, 2026, 8:00 AM ET

Theriva™ Biologics Announces Sale of SYN-004 (ribaxamase) and Related Antibiotic-Degrading Enzyme Portfolio to Biossil Labs Inc.

Theriva Biologics sold its antibiotic-degrading enzyme portfolio, including SYN-004 (ribaxamase), SYN-007, & SYN-006, to Biossil Labs Inc.
Theriva received a $350,000 upfront payment at closing & is eligible for up to $3 million in regulatory milestones, low single-digit royalties on net sales capped at $250 million, & up to $88 million in sales milestones.
Biossil assumed all responsibility & costs for the future development & commercialization of the acquired product portfolio.
The sale enables Biossil to continue clinical development of the assets, including the ongoing Phase 1b/2a trial at Washington University investigating prevention of acute graft-versus-host disease (aGVHD).
SYN-004 is an oral therapy designed to degrade IV beta-lactam antibiotics in the gut to prevent Clostridioides difficile infection, VRE, & CRE while protecting the microbiome.
SYN-007 is a reformulation intended for oral coadministration with oral beta-lactam antibiotics, while SYN-006 targets carbapenem antibiotics in addition to beta-lactams.
Theriva's lead product candidate is now VCN-01, an oncolytic adenovirus advancing toward a potential Phase 2/3 trial for retinoblastoma following successful Phase 2b results in pancreatic cancer.
The Phase 1b/2a trial at Washington University is currently paused after completing two of three cohorts evaluating safety, tolerability, & absorption in allogeneic hematopoietic cell transplant recipients.