Ruxolitinib may provide alternative treatment for patients with transfusion-dependent thalassemia
SAN DIEGO — Ruxolitinib demonstrated an improvement in transfused red blood cell volume during a 24-week treatment period compared with baseline in patients with transfusion-dependent thalassemia and splenomegaly, according to phase 2a results from the TRUTH study presented at the ASH Annual Meeting and Exposition.
Ruxolitinib also demonstrated a reduction of spleen volume in almost all study participants, according to the findings.
Splenomegaly tends to worsen anemia in patients with transfusion-dependent thalassemia, which can then lead to an increase in the need for transfusions.
“The consistent reduction in spleen size from baseline over time observed in the study patients echoes similar results reported in phase 3 trials recruiting patients with myelofibrosis and polycythemia vera,” Ali Taher, MD, deputy director for academic and research affairs at the Naef K. Basile Cancer Institute at the American University of Beirut Medical Center, told HemOnc Today.
Taher and colleagues conducted a single-arm, multicenter study of 30 adults (median age, 24 years) with thalassemia and splenomegaly who received transfusions every 4 weeks.
The primary endpoint, as Taher noted, was to determine if there was a reduction in transfusion burden with the use of ruxolitinib (Jakafi, Incyte) compared with baseline – which was defined as the period between 24 weeks before the start of treatment and week 0.
The researchers also sought to determine if there was any degree of spleen volume reduction from baseline.
Patients received a starting dose of 10 mg twice-daily and were required to receive iron chelation for at least 4 weeks prior to screening and throughout the study.
Twenty-six patients completed the core phase at week 30 and 20 of those patients continued to receive ruxolitinib beyond the core study period via other mechanisms.
Mean hematocrit adjusted volume of transfused red blood cells per 4 weeks was 605 mL during the baseline period. The adjusted volume of transfused red blood cells decreased to 560 mL between weeks 6 and 30 after treatment with ruxolitinib. Mean percent change of transfusion rate was –5.9%.
The most common adverse events that occurred during the study were upper respiratory tract infection (27%), nausea (20%), upper abdominal pain (17%), anemia (17%), diarrhea (17%) and weight gain (17%).
Eleven patients reported experiencing grade 3 or 4 adverse events that were not believed to be associated with the use of ruxolitinib.
Thirteen patients experienced adverse events that were believed to be associated with the study drug. Three of those patients reported serious adverse events.
“The overall safety-related tolerability of ruxolitinib in transfusion-dependent thalassemia patients remains to be fairly acceptable,” Taher said. “Yet a watchful eye must be kept on all patients taking the drug in anticipation of their development of drug-related complications, which might call for dose reduction in the afflicted patients.”
The mean spleen volume reduction from baseline at week 12 (N = 26) and week 30 (N = 25) was –19.7% and –26.8%, respectively.
“The sustained decrease in spleen size signifies that ruxolitinib might be promising for patients with transfusion-dependent thalassemia who are potential candidates for splenectomy, especially in light of the adverse complications of the latter, such as life-threatening infections, pulmonary hypertension, and thromboembolic complications,” Taher said. “The theoretical utility of ruxolitinib in non-transfusion-dependent thalassemia patients with splenomegaly remains an open question worthy of potential investigation in the future.” – by Ryan McDonald
Aydinok Y, et al. Abstract 852. Presented at: ASH Annual Meeting and Exposition; Dec. 3-6, 2016; San Diego.
Disclosure: Taher reports receiving research funding from Celgene and Novartis, as well as honoraria from Novartis. Please see the full study for a list of all other relevant financial disclosures.