Novartis has announced long-term study results supporting the positive safety and efficacy of Revolade (eltrombopag) in adults with chronic/persistent (enrolling patients that were 6 or more months from diagnosis) immune (idiopathic) thrombocytopenia (ITP) were published online in Blood. The EXTEND study found that a majority of patients maintained a substantial clinical response and many no longer needed concomitant ITP medications. The research evaluated patients for up to 8 years of continuous treatment (median exposure of 2.4 years).
ITP is a rare and potentially serious blood disorder where the blood doesn’t clot as it should due to a low number of platelets. As a result, patients with ITP experience bruising, bleeding and, in rare cases, serious hemorrhaging that can be fatal. The goal of treatment in chronic/persistent ITP is to maintain a safe platelet count that reduces the risk of bleeding.
EXTEND, an open-label extension study of four trials (TRA100773A, TRA100773B, TRA102537/RAISE and TRA108057/REPEAT) of Revolade, enrolled 302 adults with chronic/persistent ITP (6 or more months from diagnosis) who had received prior therapy for their ITP, and is the largest study of its kind. To qualify for the prior trials, patients must have had thrombocytopenia for at least 6 months (chronic ITP was previously defined as thrombocytopenia for 6 or more months).The objectives were to assess the safety and efficacy of long-term treatment with Revolade, including the proportion of patients achieving stable platelet counts during treatment with Revolade; maximum duration of platelet count elevation >=50×109/L or >=30×109/L during treatment with Revolade, and the effect of Revolade on reducing and/or sparing concomitant ITP therapies, while maintaining a platelet count >=50×109/L.
The study allowed each patient to achieve an individualized dose and schedule of eltrombopag based upon their platelet counts in the desired range between 50 to 200 Gi/L. Therefore, patients who were enrolled in EXTEND must have completed the treatment and follow-up periods as defined in previous protocol and must have not experienced eltrombopag-related toxicity or other drug intolerance on prior eltrombopag study even if resolved. In addition, patients who discontinued from a previous study due to toxicity were not eligible unless they received placebo.
Revolade was started at a dose of 50 mg/day and titrated to 25-75 mg/day or less often based on platelet counts. Maintenance dosing continued after minimization of concomitant ITP medication and optimization of Revolade dosing. The overall median duration of exposure was 2.37 years (range, 2 days to 8.76 years) and mean average daily dose was 50.2 (range, 1-75) mg/day. One hundred thirty five adult patients (45%) completed the study and 75 adult patients (25%) were treated for four or more years. Most patients were aged <65 years, female, and had platelet counts <30×109/L at baseline. About one-third were using concomitant medications at baseline, and 53% had received three or more prior ITP therapies. In addition, 91% (276/302) of patients achieved platelet counts >=30×109/L without rescue treatment, and 86% (259/302) achieved platelet counts >=50×109/L without rescue treatment.
Grade 3 and 4 adverse events (AEs) occurred in 26% and 6% of patients, respectively. Grade 3 cataracts occurred in four (1%) patients and Grade 3 pain in extremity in six (2%) patients. Grade 3 AEs occurring in three (<1%) patients each included diarrhea, headache, migraine, dyspnea, decreased platelet count, and menorrhagia; those occurring in five (2%) patients each included pneumonia, fatigue, back pain, increased alanine aminotransferase, increased aspartate aminotransferase, anemia, and hypertension. Grade 4 anemia and thrombocytopenia occurred in three (<1%) and four (1%) patients, respectively. All other Grade 4 events occurred in one patient each.