B7-33
/ Modified single-chain relaxin-2 analog; biased RXFP1 receptor agonistTerms in this page you can click for a plain-English popup: , , , , , , , .
Academic research-phase molecule. Designed to preserve relaxin's anti-fibrotic effects while avoiding vasodilation. No human trials.
B7-33 is a single-chain modified analog of relaxin-2 developed to bias signaling at the RXFP1 receptor toward the Akt/MAPK anti-fibrotic pathway while minimizing cAMP-mediated vasodilation. The biased-agonism hypothesis is that it could preserve cardiac anti-fibrotic benefits of relaxin without the hypotension that limited parent-relaxin (serelaxin) development.
No human trials. Preclinical mouse models of myocardial infarction and cardiac fibrosis have reported reduced fibrosis markers with B7-33 compared with full-length relaxin. Academic research-phase only.
No human safety data. The parent molecule (serelaxin) completed Phase 3 trials in acute heart failure that were negative on primary endpoints, though for distinct reasons.
Regulatory status
- FDA status:
- Not FDA-approved
B7-33 is sold in the research-chemical market despite no human trials and no pharmaceutical development program behind it. The biased-agonism rationale is mechanistically interesting but does not substitute for clinical evidence.