Eltrombopag plus immunosuppressive therapy improves response in severe aplastic anemia
Eltrombopag increased response rates when added to standard immunosuppressive therapy among patients with transplant-ineligible severe aplastic anemia, according to phase 3 study results published in The New England Journal of Medicine.
The combination of eltrombopag (Promacta, Novartis), an oral thrombopoietin-receptor agonist, and standard therapy also appeared safe, researchers wrote.
“A previous single-group, phase 2 study indicated that eltrombopag improved the efficacy of standard immunosuppressive therapy that entailed horse antithymocyte globulin plus cyclosporine in patients with severe aplastic anemia,” Régis Peffault de Latour, MD, PhD, professor of hematology in the department of hematology and bone marrow transplant at Saint-Louis Hospital in Paris, told Healio. “We needed a phase 3 randomized trial to confirm the findings.”
In the international, open-label RACE trial, Peffault de Latour and colleagues randomly assigned 197 patients with acquired severe aplastic anemia who had not received prior immunosuppressive therapy to either standard immunosuppression (n = 101; median age, 52 years), which consisted of 40 mg/kg horse antithymocyte globulin (Atgam, Pfizer) four times daily plus 5 mg/kg daily cyclosporine A, or standard immunosuppressive therapy plus 150 mg daily eltrombopag (n = 96; median age, 55 years) from day 14 through 6 months or 3 months for patients who had early disease progression.
Hematologic complete response at 3 months served as the primary endpoint.
As Healio previously reported, researchers observed 3-month complete response rates of 22% with the eltrombopag combination and 10% with standard treatment (pooled OR = 3.2; 95% CI, 1.3-7.8).
Results reported in The New England Journal of Medicine also showed overall response rates at 6 months of 68% with the eltrombopag combination vs. 41% with standard treatment.
The eltrombopag group also had a shorter median time to first response (3 months vs. 8.8 months) and higher EFS rate (46% vs. 34%).
Eltrombopag appeared well-tolerated, with comparable adverse events between the two treatment groups. One patient in the standard treatment group and two patients in the eltrombopag combination group developed myelodysplastic syndrome.
Based on these findings, standard immunosuppressive therapy plus eltrombopag has become the reference treatment for untreated patients with severe or very severe aplastic anemia, Antonio M. Risitano, MD, PhD, head of the clinical unit of hematopoietic stem cell transplantation in the department of biochemistry and medical biotechnologies at University of Naples, told Healio.
“We will conduct long-term follow-up of the RACE-2 study and exchange with the European Medicines Agency to see how European patients may access the treatment, as approval was refused in October 2019,” Risitano said.
For more information:
Régis Peffault de Latour, MD, PhD, can be reached at French Reference Center for Aplastic Anemia and Paroxysmal Nocturnal Hemoglobinuria, Universite de Paris, Saint-Louis Hospital, 1 Ave. Claude Vellefaux, 75010 Paris, France; email: firstname.lastname@example.org.
Antonio M. Risitano, MD, PhD, can be reached at email@example.com.