US FDA gives boost to potential daily oral treatment for primary ITP
Developer awarded orphan drug status for bleeding disorder med
Written by |
The U.S. Food and Drug Administration (FDA) has granted orphan drug status — a designation that aims to speed the development of therapies for rare diseases — to the experimental oral med sovleplenib as a potential treatment for primary immune thrombocytopenia (ITP).
Developer Hutchmed announced the new designation in a company press release, stating that it “underscores the potential of sovleplenib to address significant unmet medical needs in patients with this rare and serious autoimmune condition.” Its therapy aims to reduce the activity of immune cells that ultimately work to drive the disease.
The FDA awards orphan drug status to pipeline meds for rare diseases, specifically defined in the U.S. as conditions affecting fewer than 200,000 people. The designation provides extra incentives for drug developers investing in rare disease treatments, and it gives Hutchmed access to perks that include tax credits, fee waivers, and regulatory guidance. Most notably, per the developer, it guarantees seven years of market exclusivity if sovleplenib is ultimately approved by the FDA for ITP.
ITP is an immune system disorder marked by antibodies that attack and destroy platelets, cell fragments that normally help blood to clot. Low platelet counts can lead to ITP symptoms such as easy bruising and bleeding.
The condition is largely classified into two main types: Primary and secondary. Primary or idiopathic ITP is the form of the disease that is not related to a known underlying trigger. That’s opposed to secondary ITP, which is associated with an external trigger that alters immune function in ways believed to promote the condition.
Sovleplenib now under regulatory review in China for ITP
The platelet-targeting antibodies that drive ITP are produced by specialized immune cells called B-cells. Sovleplenib is designed to reduce the activity of these immune cells, thereby reducing levels of disease-driving antibodies and ultimately increasing platelet counts. The experimental therapy is designed to be taken by mouth once per day.
Hutchmed has already completed a Phase 3 clinical trial, dubbed ESLIM-01 (NCT05029635), which tested daily sovleplenib against a placebo in nearly 200 adults with primary ITP whose disease was not well controlled after at least one prior line of treatment.
The study’s main goal was to determine whether sovleplenib was better than a placebo at helping patients meet response criteria — basically meaning a sustained increase in platelet levels above a predefined threshold during the last half of the six-month-long study.
The results, published in 2024, showed that this goal was met: Nearly half (48%) of those on sovleplenib met response criteria, whereas none of the patients given a placebo did.
After the placebo-controlled part of the study, participants could continue into an open-label extension study, in which all were given sovleplenib and monitored for long-term outcomes. Data showed more than 60% of patients on long-term sovleplenib met response criteria.
Based on the findings from ESLIM-01, Hutchmed has submitted an application seeking regulatory approval of sovleplenib for ITP in China. That application is now under review.
