Handok said it has received marketing approval from the Ministry of Food and Drug Safety (MFDS) for Doptelet (avatrombopag), a treatment for chronic immune thrombocytopenia (ITP) and thrombocytopenia in patients with chronic liver disease (CLD) scheduled for invasive procedures.

The approval marks another milestone for Handok in 2024, following the authorization and insurance coverage of its new paroxysmal nocturnal hemoglobinuria (PNH) treatment, Empaveli. Developed initially by global biopharmaceutical company SOBI, Handok managed the regulatory approval process for Doptelet in Korea.

Handok has partnered with SOBI on Empaveli and Doptelet, launching a strategic collaboration that culminated in the formation of Handok-SOBI, a joint venture officially established in April 2024. Through the joint venture, Handok plans to expand its rare disease pipeline further, bringing additional innovative treatments to the Korean market.

Doptelet is an oral thrombopoietin receptor agonist (TPO-RA) designed for adults with chronic ITP who have shown an insufficient response to prior treatments.

Offering both rapid and sustained efficacy, Doptelet is a convenient option that does not require dietary restrictions. The drug has been approved in multiple regions, including the U.S., Europe, Australia, and Japan. The U.S. Food and Drug Administration approved it in June 2019, and the European Medicines Agency (EMA) approved it in January 2021 for treating ITP.

ITP is an acquired immune-mediated disorder where autoantibodies attack and destroy platelets, leading to reduced platelet counts and an increased risk of bleeding. Doptelet offers a new option for both treatment-naïve and experienced patients.

In phase 3 study 302, Doptelet demonstrated a significantly longer cumulative platelet response (median of 12.4 weeks) than placebo (median of 0 weeks). Additionally, 65.6 percent of patients treated with Doptelet achieved a platelet response (≥50,000/μL) within eight days of starting treatment, with consistent efficacy across both treatment-naïve and experienced groups.

Retrospective analysis also highlighted Doptelet’s effectiveness in patients transitioning from other TPO-RAs. Among 44 U.S. patients who switched to Doptelet, 93 percent achieved platelet counts ≥50,000/μL, and 86 percent reached platelet counts ≥100,000/μL.

Notably, patients who failed to respond adequately to previous TPO-RAs saw their median platelet counts rise from 28,000/μL to 88,000/μL after transitioning to Doptelet.

Doptelet also provides a valuable alternative for patients with chronic liver disease (CLD) experiencing thrombocytopenia, particularly those preparing for invasive procedures. Thrombocytopenia, a common complication in CLD, results from decreased liver thrombopoietin (TPO) production.

About 78 percent of cirrhosis patients suffer from thrombocytopenia, often requiring platelet transfusions before procedures. However, blood product shortages and diminishing transfusion efficacy have posed significant challenges.

In its pivotal phase 3 ADAPT-1 and ADAPT-2 trials, Doptelet significantly reduced the need for platelet transfusions or rescue therapy among CLD patients with platelet counts <40,000/μL.

Post-procedure transfusion or rescue therapy was required in 22.9 percent and 34.9 percent of placebo group patients, compared to 65.6 percent and 68.6 percent of Doptelet-treated patients.

Similarly, for patients with platelet counts between 40,000 and 50,000/μL, Doptelet eliminated the need for transfusion or rescue therapy in 88.1 percent 87.9 percent of cases, compared to 38.2 percent and 33.3 percent for the placebo groups.

“Doptelet’s approval marks a significant step in addressing unmet needs for patients with chronic ITP and CLD-associated thrombocytopenia,” Handok CEO Kim Young-jin said. “We will continue strengthening our partnership with SOBI to deliver cutting-edge rare disease therapies and enhance patients’ quality of life in Korea.”