Hutchmed is gearing up to submit sovleplenib for approval in the company’s native China after the Syk inhibitor scored a phase 3 win.
The placebo-controlled trial enrolled 188 adults in China with primary immune thrombocytopenia who had received at least one prior line of standard therapy. Thrombocytopenia involves a low blood platelet count and can lead to increased risk of bleeding.
The trial hit its primary endpoint of demonstrating a “clinically meaningful and a statistically significant increase in durable response rate” for sovleplenib when compared to placebo, while “secondary endpoints including response rate and safety were also met,” the company said.
However, Hutchmed held back any details of the results, instead promising to publish the findings at an upcoming scientific conference.
Sovleplenib is designed to inhibit spleen tyrosine kinase, or Syk, as a way to treat hematological malignancies and immune diseases. Syk is a component in the Fc receptor and B-cell receptor signaling pathway.
The drug is also being studied in a phase 2/3 trial for warm antibody autoimmune hemolytic anemia and a phase 1 study in non-Hodgkin lymphoma.
Based on the results, Hutchmed plans to submit a new drug application to Chinese regulatory authorities “around the end of 2023.” With an estimated 110,000 patients in China living with primary immune thrombocytopenia, a condition for which there are “no effective treatment options,” Hutchmed sees a viable market in its home country. There are also an estimated 145,000 patients living with the chronic form of the autoimmune disorder in major pharmaceutical markets beyond China, the company pointed out in the release.
While several treatment options already exist, they are “infrequently curative,” Hutchmed added. “Many patients develop resistance to treatment and thereby are prone to relapse.
“Thus, there remains a significant population of patients who have limited sensitivity to currently available agents and are in need of new treatments.”
Also swimming in the wider thrombocytopenia pool is Takeda. In June, the Japanese pharma released interim results from a phase 3 trial showing that patients taking its ADAMTS13 replacement therapy TAK-755 as a preventive measure didn’t have any acute thrombotic thrombocytopenic purpura attacks compared to the plasma-based therapies that are the current standard of care for the condition.
In January, Pfizer dropped a recombinant Fc fusion protein that had been in phase 1 development for both primary immune thrombocytopenia and chronic inflammatory demyelinating polyneuropathy.