Hutchmed publishes positive sovleplenib trial results

The AIM-traded firm said sovleplenib, a novel, selective oral inhibitor targeting spleen tyrosine kinase (Syk), was evaluated for treating adult patients with primary immune thrombocytopenia (ITP) in China.

It said the study demonstrated a durable response rate of 48.4% compared to 0% with placebo, marking a significant potential advancement in ITP treatment.

The ESLIM-01 trial, a randomised, double-blind study involving 188 adult patients who had received at least one prior ITP treatment, showed a meaningful and sustained platelet response with sovleplenib, along with a tolerable safety profile and improvements in quality of life.

Hutchmed said the trial's primary endpoint was achieved, with sovleplenib showing a durable response rate of 48.4% versus none for the placebo group.

Additionally, sovleplenib achieved overall response rates of 68.3% at zero to 12 weeks, and 70.6% at zero to 24 weeks, significantly higher than the placebo group’s results of 14.5% and 16.1%, respectively.

Subgroup analyses presented at the European Hematology Association (EHA) 2024 Hybrid Congress demonstrated consistent benefits across various patient demographics, irrespective of prior lines of therapies or prior exposure to TPO/TPO-RA treatments.

Patients with four or more prior lines of therapy showed a durable response rate of 47.7% with sovleplenib, compared to 0% with placebo.

Furthermore, 74.6% of patients in the sovleplenib group who had received prior TPO/TPO-RA treatments demonstrated a durable response rate of 46.8% versus none in the placebo group.

Hutchmed said the safety profile of sovleplenib was consistent with previous studies, with most treatment-emergent adverse events being mild or moderate in severity.

Grade three or higher adverse events were reported in 25.4% of sovleplenib-treated patients compared to 24.2% in the placebo group.

Additionally, sovleplenib significantly improved quality of life metrics related to physical functioning, and energy or fatigue.

The positive trial outcomes supported regulatory submission in China, with the National Medical Products Administration (NMPA) granting breakthrough therapy designation and accepting the new drug application (NDA) for priority review in January.

A dose-finding study was planned for the US, and Hutchmed said it had also initiated a phase two and three clinical trial for sovleplenib in treating warm antibody autoimmune hemolytic anaemia (wAIHA) in China.

Hutchmed said it retained all global rights to sovleplenib.

At 0834 BST, shares in Hutchmed China were down 3.34% at 283.2p.

Reporting by Josh White for Sharecast.com.