Omeros has discontinued a phase 3 trial involving narsoplimab for kidney disease patients due to a mid-stage evaluation indicating its inevitable failure. The Seattle-based company initially sought approval for the anti-MASP2 antibody to treat a complication arising from a hematopoietic stem cell transplant in 2020. However, the FDA rejected their application, prompting Omeros to formally contest the decision and subsequently identify an alternative path for potential approval in that particular medical condition.
Concurrently, Omeros was actively pursuing phase 3 data on narsoplimab in immunoglobulin A (IgA) nephropathy.
Unfortunately, the IgA nephropathy project ended with a disappointing outcome during an interim review. The assessment revealed that narsoplimab did not show statistically significant superiority over a placebo in reducing proteinuria—a condition characterized by elevated protein levels in urine- indicating kidney damage.
In a phase 2 clinical trial, Omeros had associated their drug candidate with a remarkable 64% reduction in proteinuria, presenting a seemingly competitive edge compared to similar products like Calliditas Therapeutics’ Tarpeyo and Novartis’ iptacopan. However, this phase 2 study lacked a control arm, and when confronted with a placebo in the subsequent phase 3 trial, the promising effect of narsoplimab diminished.
Omeros pointed out that the reduction in urine protein excretion observed in the placebo group was notably greater than what had been reported in trials involving other agents for IgA nephropathy.
While some biotech companies sometimes leverage high placebo rates to justify further research on unsuccessful candidates, Omeros made a decisive shift away from IgA nephropathy. They announced the discontinuation of the study and abandoned plans to seek approval for this indication.
This strategic pivot removes a potential competitor for Calliditas and Travere Therapeutics, the established players in the market, and enables Omeros to redirect investments toward other projects. As of June, Omeros had $341.3 million in funds, sufficient to sustain their operations through 2025.