Eli Lilly has discontinued its Phase II clinical trial of volenrelaxin, an investigational relaxin analog, for the treatment of chronic kidney disease (CKD). The decision, revealed through an update on clinicaltrials.gov, was attributed to a "lack of foreseeable clinical benefit" in the targeted CKD patient population.
The termination notice also referenced a related heart failure study that was halted after demonstrating no benefit in an overlapping patient group. While the specific heart failure study remains unclear, it has raised concerns within the pharmaceutical industry regarding the broader potential of relaxin-based therapies for cardiopulmonary diseases.
Impact on Tectonic Therapeutics
The news of Lilly's terminated trial has significantly impacted Tectonic Therapeutics, a Massachusetts-based biotech company. Tectonic's stock price plummeted as much as 40% following the announcement. Tectonic is currently developing TX45, a relaxin fusion molecule targeting the RXFP1 receptor, for the treatment of pulmonary hypertension in patients with heart failure with preserved ejection fraction (PH-HFpEF).
Analyst Perspective
Analysts at Leerink Partners noted that Lilly's decision to terminate the volenrelaxin study has caused significant concern about the likelihood of success of TX45. Both volenrelaxin and TX45 are long-acting relaxin mechanism candidates for cardiopulmonary diseases.
However, in a follow-up note, Leerink analysts reiterated their confidence in Tectonic, highlighting key differences between the two drugs. TX45 employs a different relaxin approach and is being tested for distinct indications with different endpoints. Tectonic is anticipating a Phase Ib readout in the first quarter of 2025.
Volenrelaxin: Mechanism and Previous Findings
Volenrelaxin is a synthetic analog of the human relaxin protein that activates the relaxin receptor. Preclinical studies in animals demonstrated that volenrelaxin could elicit relaxin-related pharmacological responses, including increased renal blood flow in rats. A Phase I trial found volenrelaxin to be safe and suitable for subcutaneous dosing and identified promising signals of efficacy, including sustained improvement in kidney perfusion upon repeated dosing.
