ORLANDO – For the first time, there is a maintenance therapy for patients with acute myeloid leukemia (AML) in remission that can improve overall survival – a new oral formulation of an old drug, azacitidine, known as CC-486 (Celgene).
“Oral azacitidine represents a new therapeutic standard for patients with AML in remission,” said lead author Andrew H. Wei, MBBS, PhD, from the Alfred Hospital in Melbourne.
“It’s not too hard to get these patients into remission,” commented another expert. “The problem comes in keeping them in remission.”
Dr. Wei noted that standard treatment with intensive induction chemotherapy for AML induces complete remission (CR) in 60%-80% of patients aged 60 years or younger and in 40%-60% of patients aged 60 years or older.
However, the majority of patients who attain complete remission (CR) will eventually relapse, and relapse is the primary obstacle to long-term survival, he said.
Despite various attempts, there has been no success over the past 30 years in defining maintenance treatment for these patients, Dr. Wei said.
The new results suggest that oral azacitidine could be an effective maintenance therapy.
Dr. Wei presented the results at the 2019 annual meeting of the American Society of Hematology. They come from the QUAZAR AML-001 study, conducted in 472 patients with poor-risk AML in first remission.
The results show that CC-486 significantly improved outcomes, compared with placebo plus best supportive care, in terms of median overall survival (24.7 vs. 14.8 months) and median relapse-free survival (10.2 vs. 4.8 months).
The trial was funded by Celgene, which said it will be submitting the data for regulatory approval for the new oral formulation of azacitidine, CC-486.
Experts predict new standard of care
Experts approached for comment agreed that maintenance oral azacitidine will become the new standard of care for patients with AML in first remission.
“Unlike therapy for acute lymphoblastic leukemia, maintenance therapy has not been part of the treatment algorithm for AML patients in first remission,” Harry P. Erba, MD, PhD, director of the leukemia program at the Duke Cancer Institute, Durham, N.C., told Medscape Medical News.
He explained that trials for maintenance after first remission in AML have failed. Recently, Dr. Erba noted, the HOVON97 trial with injectable azacitidine demonstrated improvement in relapse-free survival, compared with observation for older AML patients achieving remission after induction therapy. “However, there was no improvement in overall survival,” he said.
“Remission in AML is short lived,” Dr. Erba said. Oral azacitidine represents the first maintenance therapy in AML that has shown both significant and clinically meaningful improvements in overall and relapse-free survival and will represent a new standard of care for patients with AML in remission, Dr. Erba said. “Maintenance oral azacitidine will be practice changing,” he predicted.
HOVON97 was a small study of injectable azacitidine used as maintenance therapy for 12 months, but it was slow to accrue and did not meet its accrual target.
“In HOVON97, at 12 months, only one third of patients received less than the 12 cycles of therapy,” Dr. Wei said. He explained that, with injectable azacitidine, patients have to come into the hospital/clinic for 7 days a month, 84 days a year. Oral azacitidine is more convenient as patients do not have to come into the clinic, he said.
Dr. Wei pointed out that about 40 patients in the QUAZAR study, which started in 2013, are still on maintenance therapy, with one patient now having received 80 cycles of therapy (approximately 7 years). “Long-term maintenance therapy with azacitidine is possible,” he said.
Another expert was also impressed by the new results. “This is an important clinical trial that addresses an unmet need in AML care,” said John Mascarenhas, MD, director of the Adult Leukemia Program and leader of clinical investigation within the myeloproliferative disorders program at the Tisch Cancer Institute at the Icahn School of Medicine at Mount Sinai, New York.
“Older patients can often receive induction chemotherapy but frequently do not ultimately do well, as the disease relapses and survival is limited,” he explained.
“This large, randomized, double-blind, controlled study of intermediate- or poor-risk AML patients over the age of 55 years supports the use of maintenance oral azacitidine after initial remission to extend overall and relapse-free survival in older AML patients not eligible for transplant,” Dr. Mascarenhas said.
“This is still not a curative approach,” Dr. Wei said, but added that it prolongs relapse-free survival for older patients while maintaining a quality of life for as long as possible.