Doptelet, Doptelet Sprinkle for pediatric ITP win FDA approval
OK based on findings from Phase 3b clinical study AVA-PED-301
Sobi’s Doptelet (avatrombopag), which is available as a tablet and an oral granule called Doptelet Sprinkle, is now approved in the U.S. for children ages 1 and older with persistent or chronic immune thrombocytopenia (ITP) who haven’t responded well to previous treatments.
With the U.S. Food and Drug Administration’s (FDA) approval, Doptelet becomes one of the few thrombopoietin receptor agonists (TPO-RAs) for pediatric patients and a noninvasive alternative to injectable treatments.
“This approval not only reinforces our commitment to innovation, but also allows us to expand the treatment experience for patients and their families by offering Doptelet in two formulations,” Duane Barnes, president of Sobi North America, said in a company press release.
Doptelet Sprinkle, approved for children younger than 6, are capsules that should be opened so their contents can be mixed with soft food or liquid. Children ages 6 and older are approved for Doptelet tablets.
The decision follows Sobi’s submission of a supplemental new drug application to expand Doptelet’s use beyond adults with chronic ITP who’ve had an inadequate response to previous treatments.
In ITP, the immune system mistakenly attacks and destroys cell fragments, called platelets, that help blood clot, which results in symptoms such as easy bruising and prolonged bleeding. While it’s often manageable in adults, persistent or chronic ITP in children can be more difficult to treat and distressing for families.
What does Doptelet do in ITP?
Doptelet stimulates the thrombopoietin receptor on precursor cells in the bone marrow, prompting more platelets to be produced. Unlike treatments that suppress the immune system, it leverages the body’s own mechanisms to increase platelets.
Its approval was based on positive findings from AVA-PED-301, a Phase 3b clinical study (NCT04516967) involving 75 children, ages 1 to 17, with primary ITP that had lasted for at least six months and who’d received one or more previous treatments. The patients were randomly assigned to either Doptelet once daily or a placebo for 12 weeks, or about three months.
The study met its main goal, with 28% of patients treated with Doptelet achieving a durable response — where a set threshold of at least 50 billion platelets per liter was met for at least six of the last eight weeks of treatment — compared with none of those on a placebo.
The alternative main goal was also met, with 81.5% of patients on Doptelet achieving platelet counts of at least 50 billion platelets per liter at least twice, in the absence of rescue treatment, compared with none on a placebo. More than half the patients on Doptelet (55.6%) achieved that threshold within eight days.
“Doptelet represents a significant advancement in the treatment of children and adolescents with persistent or chronic ITP,” said Rachael Grace, MD, who led the AVA-PED-301 study. It “offers simple, flexible administration because it is oral, available as a tablet and now as a new pediatric sprinkle formulation and has no food restrictions.”
For Grace, a pediatric hematologist and director of hematology clinical research at Dana-Farber/Boston Children’s Cancer and Blood Disorders Center, Doptelet’s approval for “pediatric ITP offers families a new treatment option that can help address challenges in managing ITP in pediatric patients.”
Those who completed the randomized part of the study, or who didn’t respond to the highest Doptelet dose, could enroll in an ongoing open-label extension where all can receive Doptelet for up to two years.
The most common side effects reported with Doptelet were viral infection, symptoms of the common cold, cough, fever, and a sore throat. The company continues to test how safe Doptelet is and how well it works in the open-label extension.
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