Exclusive: Astellas’ Xospata Provides Strong OS Benefits in Phase III Trial
Astellas’ blood cancer drug Xospata continues to demonstrate impressive results in the acute myeloid leukemia setting. During a presentation at the American Association for Cancer Research meeting over the weekend, Astellas touted new overall survival data for Xospata.
Japan-based Astellas said the Phase III ADMIRAL trial comparing Xospata (gilteritinib) to salvage chemotherapy in adult patients with relapsed or refractory AML with an FLT3 mutation showed that patients treated with Xospata had “significantly longer” overall survival data than those who only received standard salvage chemotherapy. The Phase III ADMIRAL trial was an open-label, multicenter, randomized study of gilteritinib versus salvage chemotherapy in adult patients with FLT3 mutations who are refractory to or have relapsed after first-line AML therapy. The 371-patient trial randomized the subjects in a 2:1 ratio to receive Xospata or salvage chemotherapy. Results from the ADMIRAL trial show the median OS for patients who received Xospata was 9.3 months compared to 5.6 months for patients who received salvage chemotherapy. One-year survival rates were 37 percent for patients who received Xospata compared to 17 percent for patients who received salvage chemotherapy.
“Overall survival is a benchmark clinicians often rely upon to select treatments for patients with life-threatening diseases,” Andrew Krivoshik, senior vice president and Oncology Therapeutic Area Head at Astellas Pharma told BioSpace over the weekend. “The positive data presented at AACR underscore the important role that Xospata may play in the treatment of patients with relapsed/refractory FLT3mut+ AML.”
The U.S. Food and Drug Administration approved Xospata in November for this AML indication, a rare and life-threatening disease mutation. It was the first FLT3-targeting therapy to be approved for these patients. Of the 19,000 people in the United States who are estimated to be diagnosed with AML this year, nearly 40 percent will have an FLT3 mutation. The Astellas drug has shown itself to be effective against two FLT3 mutations, FLT3 internal tandem duplication (ITD) and FLT3 tyrosine kinase domain (TKD).
Alexander Perl, an associate professor of Hematology-Oncology in Penn’s Perelman School of Medicine and an Astellas trial researcher, said the findings of the Phase III ADMIRAL trial are encouraging for this patient population. Perl said patients with relapsed/refractory FLT3 mutation-positive AML generally have a poor prognosis and short survival.
“Until just recently, they had few treatment options. These findings change the treatment paradigm for this patient population,” Perl said in a statement.
The most common treatment-emergent adverse events that occurred in more than 10 percent of patients included anemia, increased alanine aminotransferase, increased aspartate aminotransferase, febrile neutropenia, thrombocytopenia, constipation, fatigue, nausea, cough, headache and diarrhea.
Astellas is currently investigating Xospata in various FLT3 mutation-positive AML patient populations through several Phase III trials. In addition to its approval in the United States, Xospata has also been cleared for use in Japan. A Marketing Authorization Application was submitted in Europe in February.