Hetrombopag is safe, effective for ITP in real-world settings: Study
Better outcomes tied to higher starting dose, greater megakaryocyte count
Hetrombopag appears to be a safe and effective option in real-world settings for immune thrombocytopenia (ITP), with better outcomes linked with a higher starting dose and a greater number of the cells that produce platelets, called megakaryocytes, in bone marrow, a study finds.
The study, “Real-world experience of hetrombopag in immune thrombocytopenia treatment: a retrospective cohort study,” was published in the European Journal of Medical Research.
ITP is an autoimmune disease that occurs when the immune system attacks platelets, which help blood to clot. Low numbers of them can lead to bruising, bleeding, and other symptoms.
Hetrombopag is a thrombopoietin receptor agonist (TPO-RA) that helps the body produce more platelets by stimulating the bone marrow. It was developed, and is approved in China, where it’s marketed as Hengqu, as a second-line treatment for primary ITP.
To address a deficit of real-world data on the use of hetrombopag, researchers in China retrospectively analyzed safety and efficacy data from 50 patients with ITP treated at either a starting dose of 2.5 or 5 mg once daily. The patients were a median age of 47 and most (74%) were women. Most had chronic ITP, with a median disease duration of 20 months, and all had previously received at least one other treatment.
Response to hetrombopag treatment
The main goal was to see how many patients were able to reach a safe platelet count (at least 50 billion platelets per liter) after 4, 8, and 12 weeks. Before treatment, the mean platelet count was very low, at 16 billion platelets per liter.
The patients responded to treatment within a median of seven days. By week 12, their mean platelet count had increased to 104 billion platelets per liter and most patients (71%) had a successful response.
Those starting at 5 mg daily had better results than those who began with 2.5 mg. In fact, 11 who didn’t respond at 2.5 mg were switched to 5 mg, and more than half responded after that, suggesting a higher starting dose may be more effective for many patients.
Hetrombopag worked well even in those who’d tried multiple previous treatments. About a quarter of the patients used it as a second-line treatment and it was a third-line or later for the rest. While the patients responded slightly better when hetrombopag was used earlier, the differences weren’t statistically significant.
Some patients had previously been on eltrombopag, another TPO-RA with a structure similar to hetrombopag that’s approved for ITP in the U.S. where it’s sold as Promacta and Alvaiz. Of the eight patients who didn’t respond to eltrombopag, seven responded after switching to hetrombopag, with their platelet count improving steadily over 12 weeks.
Hetrombopag was generally safe. Two patients reported mild headaches and one had a small increase in liver enzymes, a sign of liver damage. No severe side effects were reported.
The researchers also looked at whether certain factors affected how well hetrombopag worked. The patients with a normal body mass index (BMI), a measure of body fat that takes weight and height into account, responded better than those with an abnormal BMI. Those with more megakaryocytes before treatment also had better outcomes.
“Hetrombopag was effective and safe in the real-world treatment of ITP. An initial dosage of hetrombopag 5 mg [daily] and a higher megakaryocyte count in bone marrow may predict better therapeutic efficacy,” the researchers wrote.
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