MEETING NEWS
Updates from recent hematology/oncology meetings
RADIUS: Midostaurin Reduces Post-Transplant Relapse
Risk in FLT3-Mutated AML
Post-transplant maintenance therapy with midostaurin was
safe and reduced relapse risk in patients with FLT3-mutated
acute myeloid leukemia (AML), according to findings from the
phase II RADIUS trial presented at the 2019 Transplantation
& Cellular Therapy (TCT) Meetings of the American Society for
Blood and Marrow Transplantation (ASBMT) and the Center for
International Blood & Marrow Transplant Research (CIBMTR),
formerly known as the BMT Tandem Meetings. The results also
demonstrated that midostaurin-treated patients who experi-
enced greater inhibition of phosphorylated FLT3 (pFLT3) had a
greater likelihood of remaining disease-free.
“Some institutional [experience] and small phase II randomized
studies have suggested that post-transplant [tyrosine kinase
inhibition] might actually improve and enhance the outcomes of
patients,” said lead study author Richard T. Maziarz, MD, from
Oregon Health & Science University, during his presentation.
In the randomized, open-label, phase II RADIUS trial, inves-
tigators evaluated whether adding the tyrosine kinase inhibitor
midostaurin to standard of care (SOC) extended relapse-free
survival (RFS), compared with SOC alone. SOC included anti-
infective and graft-versus-host disease (GVHD) prophylaxis and
treatment; midostaurin 50 mg was administered twice daily in
18
Focus on Myeloid Malignancies
28-day treatment cycles.
As of a data cutoff of April 30, 2018, a total of 60 patients were
randomized: 30 in the midostaurin arm and 30 in the SOC arm.
One patient in each arm did not receive treatment, leaving 29
evaluable patients in each arm. All participants had undergone
allogeneic hematopoietic cell transplantation (alloHCT) and start-
ed maintenance treatment within 60 days post-transplant. Patient
characteristics were “relatively well matched” between both
groups, Dr. Maziarz noted, although patients in the midostaurin
group tended to be younger than in the SOC group (median ages:
48 years and 56 years, respectively).
Half of the RADIUS participants completed all 12 treatment
cycles, with a median duration of exposure of 10.5 months
(range = 0.2-11.5 months) and a median dose intensity of 93
mg/day (range = 15-100 mg/day).
During 24 months of follow-up, 13 patients in the midostaurin
arm and 15 in the SOC arm discontinued treatment, mostly due
to adverse events (AEs) in the midostaurin arm and to consent
withdrawal in the SOC arm.
Dr. Maziarz reported that there was a higher incidence of
low-grade gastrointestinal AEs in the midostaurin arm, in-
cluding vomiting, nausea, and diarrhea. However, there was no
significant difference between incidence of grade 3/4 AEs. The