Outcomes in children with first-relapsed acute lymphoblastic leukemia in Japan: Results from JCCG Study JPLSG-ALL-R08

• Published in: Pediatric blood & cancer p. e31319
• Main Authors: Yamanaka, Junko, Ogawa, Chitose, Arakawa, Ayumu, Deguchi, Takao, Hori, Toshinori, Kiyokawa, Nobutaka, Ueki, Hideaki, Nishi, Masanori, Mochizuki, Shinji, Nishikawa, Takuro, Kumamoto, Tadashi, Nishiuchi, Ritsuo, Kikuta, Atsushi, Yamamoto, Shohei, Koh, Katsuyoshi, Hasegawa, Daisuke, Ogawa, Atsushi, Watanabe, Kenichiro, Sato, Atsushi, Saito, Akiko M, Watanabe, Tomoyuki, Manabe, Atsushi, Horibe, Keizo, Goto, Hiroaki, Toyoda, Hidemi
• Format: Journal Article
• Language: English
• Published: United States 12.09.2024
• Subjects: minimal residual disease; risk stratification; prognosis; pediatric
• ISSN: 1545-5009; 1545-5017; 1545-5017
• DOI: 10.1002/pbc.31319

The Berlin-Frankfurt-Münster (BFM)-S classification is a crucial prognostic indicator in children experiencing first-relapsed acute lymphoblastic leukemia (ALL). Early molecular response to therapy, evaluated by measurable/minimal residual disease (MRD), has a significant impact on the survival of patients with childhood ALL. Applying risk stratification based on the BFM-S classification and MRD response after induction, the first nationwide prospective multicenter study, ALL-R08, was conducted in children with first-relapsed ALL in Japan. The ALL-R08 study comprised two parts: ALL-R08-I, an observational study aimed at obtaining an overall picture of outcomes in first-relapsed childhood ALL, and ALL-R08-II, a clinical trial for the non-T-ALL S2 risk group. In ALL-R08-II, patients with an MRD level of ≥10 at the end of induction therapy were assigned to undergo allogeneic hematopoietic stem cell transplantation (allo-HCT), whereas those with an MRD level less than 10 and isolated extramedullary relapse continued to receive chemotherapy. In total, 163 patients were enrolled in the ALL-R08 study, and 82 and 81 patients were enrolled in the ALL-R08-I and the ALL-R08-II, respectively. In ALL-R08-I, the probability of 3-year event-free survival (EFS) for patients with S1, S2, S3, S4, and post-HCT groups was 83% ± 15%, 37% ± 11%, 28% ± 8%, 14% ± 7%, and 0%, respectively. In the ALL-R08-II trial, 3-year EFS in patients with post-induction MRD less than 10 and ≥10 was 70% ± 9% (n = 27) and 68% ± 8% (n = 31) (p = .591), respectively. ALL-REZ BFM-type treatment is equally effective for children with first-relapsed ALL treated according to the Japanese frontline protocols and for children with first-relapsed ALL treated according to the BFM-type frontline protocols.