In a recent press release, biopharmaceutical company Swedish Orphan Biovitrum AB (“Sobi”) shared that the first patient was dosed in a Phase 3 clinical trial evaluating avatrombopag for pediatric patients with immune thrombocytopenia (ITP). Immune thrombocytopenia is also known as idiopathic thrombocytopenic purpura. During the course of the trial, researchers will analyze avatrombopag’s safety, efficacy, tolerability, and pharmacokinetic properties.
Idiopathic Thrombocytopenic Purpura (ITP)
Immune thrombocytopenia, or idiopathic thrombocytopenic purpura (ITP), is a bleeding disorder with an unknown (“idiopathic”) cause. ITP happens after the immune system develops antibodies against platelets, usually used for normal blood clotting. In some cases, researchers believe it could develop in children following a viral infection. 80% of pediatric patients usually experience spontaneous remission. However, the other 20% (an estimation) will develop chronic ITP.
Although ITP may cause anxiety and sporadic bleeds, it has a low mortality rate and patients are able to maintain normal bone marrow. Patients with ITP may or may not show symptoms. If symptoms do appear, they may include:
- Red or purple spots under the skin that appear following superficial bleeding
- Easy or excessive bruising
- Bloody urine or stool (caused by gastrointestinal bleeding)
- Severe mouth or nose bleeds
- Excessively heavy menstrual flow (for females)
In rare cases, ITP may cause intracranial bleeding. If someone is experiencing stroke-like symptoms, please see your doctor immediately.
Also known as Doptelet, avatrombopag is a thrombopoietin receptor agonist (TPO-RA). According to ScienceDirect, thrombopoietin (TPO):
plays several important roles in the formation of the megakaryocyte, including increasing the production of megakaryocyte precursors, inhibiting megakaryocyte apoptosis, and promoting megakaryocyte maturation
Megakaryocytes are a large bone marrow cell that helps produce platelets. Currently, avatrombopag is FDA- and EMA-approved for adult patients with thrombocytopenia and chronic liver disease who are set to undergo some sort of invasive surgical procedure. It is also approved for adult patients with ITP whose condition is treatment-averse.
In the Phase 3 AVA-PED-301 clinical trial, researchers will evaluate avatrombopag for pediatric patients with ITP. The initial double-blind period will last for approximately 12-weeks, with an open-label extension for up to 2 years. 72 patients will enroll. Throughout the trial, researchers will evaluate the impact of avatrombopag as compared to a placebo.