Gilteritinib versus chemotherapy in Japanese patients with FLT3-mutated relapsed/refractory acute myeloid leukemia.

BACKGROUND: Until recently, no effective targeted therapies for FLT3-mutated (FLT3mut+) relapsed/refractory (R/R) acute myeloid leukemia (AML) were available in Japan. The FLT3 inhibitor, gilteritinib, was approved in Japan for patients with FLT3mut+ R/R AML based on the phase 3 ADMIRAL trial, which demonstrated the superiority of gilteritinib over salvage chemotherapy (SC) with respect to overall survival (OS; median OS, 9.3 vs 5.6 months, respectively; hazard ratio, 0.64 [95% confidence interval 0.49, 0.83]; P < 0.001). METHODS: We evaluated the Japanese subgroup (n = 48) of the ADMIRAL trial, which included 33 patients randomized to 120-mg/day gilteritinib and 15 randomized to SC. RESULTS: Median OS was 14.3 months in the gilteritinib arm and 9.6 months in the SC arm. The complete remission/complete remission with partial hematologic recovery rate was higher in the gilteritinib arm (48.5%) than in the SC arm (13.3%). After adjustment for drug exposure, fewer adverse events (AEs) occurred in the gilteritinib arm than in the SC arm. Common grade ≥ 3 AEs related to gilteritinib were febrile neutropenia (36%), decreased platelet count (27%), and anemia (24%). CONCLUSION: Findings in Japanese patients are consistent with those of the overall ADMIRAL study population.

Clinical profile of gilteritinib in Japanese patients with relapsed/refractory acute myeloid leukemia: An open-label phase 1 study.

Gilteritinib, a novel, highly specific, potent fms-like tyrosine kinase 3/AXL inhibitor, demonstrated antileukemic activity in patients with relapsed/refractory (R/R) acute myeloid leukemia (AML). In this open-label phase 1 study (NCT02181660), Japanese patients (aged ≥18 years) with R/R AML received once-daily gilteritinib, escalating from 20 to 300 mg/d. Primary endpoints were safety/tolerability, including the maximum tolerated dose (MTD) and the recommended dose (RD); secondary endpoints were antileukemic activity and pharmacokinetics (PK). Twenty-four Japanese patients with R/R AML received once-daily oral gilteritinib in 1 of 6 dose-escalation cohorts (20, 40, 80, 120, 200, and 300 mg/d). Gilteritinib was well tolerated. The MTD was 200 mg/d; dose-limiting toxicities were grade 3 tumor lysis syndrome (120 mg/d; n = 1); and grade 3 elevated blood lactate dehydrogenase, amylase, blood creatine phosphokinase levels, and syncope (all n = 2; 300 mg/d). The RD was 120 mg/d. The most common drug-related grade ≥3 adverse events were thrombocytopenia (n = 4 [16.7%]) and increased blood creatine phosphokinase (n = 3 [12.5%]). Gilteritinib had a dose-proportional PK profile. Among patients with mutated fms-like tyrosine kinase 3, the overall response rate (ORR) was 80% (n = 4 of 5; complete remission [CR] with incomplete platelet recovery, 1 [20%]; CR with incomplete hematologic recovery, 2 [40%]; partial remission (PR), 1 [20%]). Among patients with wild-type fms-like tyrosine kinase 3, ORR was 36.4%; (n = 4 of 11; CR, 1 [9.1%]; CR with incomplete platelet recovery, 2 [18.2%]; PR, 1 [9.1%]). In conclusion, gilteritinib was well tolerated and demonstrated antileukemic activity in a Japanese R/R AML population.

Characteristics of the Compassionate Use Program in Japan: An Analysis of Expanded Access Clinical Trials from 2016 to 2021.

Compassionate use is a system that provides patients with exceptional access to investigational new drugs to treat life-threatening diseases that have no effective conventional treatments. The purpose of this study was to characterize and assess the current status of the compassionate use program's application in Japan by evaluating expanded access clinical trials (EACTs) conducted between 2016 and 2021. In this study, a data set containing all EACTs, and pivotal clinical trials (PCTs) conducted in Japan between February 2016 and April 2021 was obtained from the Pharmaceutical and Medical Devices Agency, systemically reviewed, and analyzed. During the 5 years since EACTs began in Japan, out of 2,031 PCTs, 31 EACTs were conducted in Japan. Twenty-four trials (77.4%) of the 31 EACTs used anticancer drugs and 5 of those trials (16.1%) were conducted in children. Furthermore, we conducted an EACT survey for drugs with a high degree of social and patient demands as recommended in the EACT notification. Among the 2,031 PCTs, we found 152 trials with high degree of social and patient demands. Of these, EACT was implemented in 17 trials (11.2%). Days from the start of the EACT to the submission of new drug applications and the approval were 9.0 (67.0-56.5) and 208.0 (172.8-308.8) days, respectively. Of the 31 EACTs conducted, 24 (77.4%) drugs have been approved as of August 2021. This first comprehensive study on EACTs clarified the current status and issues of Japan's compassionate use system and the 5 years since the program initiated.