Hemophilia A drug Hemlibra demonstrates long-term safety, sharply cutting exercise-related bleeding risk

Long-standing concerns about thrombotic complications associated with the hemophilia A treatment Hemlibra (emicizumab), which had led some physicians to hesitate to prescribe the drug, have been eased by newly presented large-scale, long-term real-world data.

The findings showed that the risk of thrombosis remains extremely low during prolonged treatment and that the therapy effectively prevents bleeding even during vigorous physical activity.

JW Pharmaceutical held the HAVEN-SEVEN Symposium on June 13 at the Westin Josun Parnas in Seoul to commemorate the seventh anniversary of Hemlibra’s approval in Korea. (KBR photo)

JW Pharmaceutical said Wednesday that it held the “HAVEN-SEVEN Symposium” on June 13 to mark the seventh anniversary of Hemlibra’s approval in Korea. The symposium brought together Korean hemophilia specialists to review long-term safety data collected since the drug’s global launch and to discuss strategies to improve patients’ quality of life beyond bleeding prevention.

One of the main topics of the meeting was thrombotic safety, a longstanding concern among clinicians.

Professor Park Young-shil of the Department of Pediatrics at Kyung Hee University Hospital at Gangdong presented “Safety Evidence Confirmed Through Global Data and Korean Real-World Data,” introducing safety findings from more than 24,000 patients accumulated over a decade of global clinical use.

“Despite the continuous increase in the number of treated patients, the incidence of severe thromboembolic events remained extremely low at just 0.17 cases per 100 patient-years,” Professor Park said.

She further noted that only one newly reported case of thrombotic microangiopathy (TMA) occurred under conditions involving excessive use of activated prothrombin complex concentrate (aPCC) beyond guideline recommendations, while no related risk has been identified with Hemlibra monotherapy.

“Long-term safety profiles have also been confirmed through real-world data from the United Kingdom, the United States, and Europe, as well as data from special patient populations, including elderly patients and infants,” she said.

The findings suggest that concerns over thrombosis associated with Hemlibra are largely unfounded when the drug is administered alone.

The symposium also highlighted real-world evidence showing that Hemlibra significantly expands patients’ ability to engage in physical activities.

Professor Han Jung-woo of the Department of Pediatrics at Severance Hospital presented findings from a study that followed 112 patients with hemophilia A who participated in regular exercise programs over a 12-month period.

According to Professor Han, neither exercise frequency nor participation in high-risk sports directly increased bleeding risk. Among patients who switched from conventional therapies to Hemlibra, exercise-related bleeding events accounted for only 0.2 percent of cases.

The results indicate that patients receiving Hemlibra can participate in physical activities with minimal concern about bleeding episodes.

Professor Baek Hee-jo of Chonnam National University Hwasun Hospital, the final speaker at the symposium, emphasized that declining annualized bleeding rates (ABR) may create a “floor effect,” making it increasingly difficult to assess patient outcomes based solely on ABR.

“In treatment environments where ABR is already very low, additional indicators such as joint health, patient-reported outcomes, and treatment burden should be considered together,” Professor Baek said.

Baek added that data from adults with severe non-inhibitor hemophilia A in five European countries showed lower levels of anxiety and depression among patients receiving Hemlibra prophylaxis compared with those receiving conventional factor 8 prophylaxis.

Productivity loss was also lower in the Hemlibra group, at 31 percent, compared with 50 percent among patients receiving conventional therapy, the professor noted.

JW Pharmaceutical said it plans to continue sharing life-stage treatment strategies based on Hemlibra’s long-term safety and real-world clinical data. The company aims to help establish a patient-centered treatment environment that considers not only bleeding prevention but also physical activity, joint health, and quality of life.

“This symposium provided an opportunity to openly share long-term safety data and real-world clinical value of Hemlibra that healthcare professionals have been eager to see,” a JW Pharmaceutical official said. “We will continue to strengthen academic exchanges with medical professionals so that people with hemophilia can enjoy ordinary lives without concerns about thrombosis or bleeding.”