Nilotinib (Tasigna®) and Low Intensity Chemotherapy for First-Line Treatment of Elderly Patients with BCR-ABL1-Positive Acute Lymphoblastic Leukemia: Final Results of a Prospective Multicenter Trial (EWALL-PH02)

Abstract

Background. Tyrosine kinase inhibitors (TKI) are standard front-line therapy for patients with BCR-ABL1/Philadelphia positive ALL (Ph+ ALL), but the relative merits of available TKIs remain uncertain. Nilotinib is a potent inhibitor of BCR-ABL1 with broader activity against ABL kinase domain mutations than imatinib and greater selectivity than dasatinib or ponatinib. As there is a paucity of data on nilotinib as first-line therapy for Ph+ ALL, the EWALL (European Working Group for Adult ALL) conducted an international clinical trial to evaluate efficacy and safety of the combination of nilotinib with low intensity chemotherapy.Patients and Methods. After a prephase with dexamethasone (DEX) and cyclophosphamide, nilotinib (400 mg BID) was given concurrently with the same chemotherapy backbone employed in the EWALL-PH01 assessing the combination with dasatinib (Rousselot et al, Blood 2016;128:774-82). Induction consisted of nilotinib combined with weekly vincristine (VCR, 1mg iv) and oral dexamethasone 40mg 2 days (20 mg over 70y). Nilotinib was continued throughout six consolidation cycles, followed by 24 months maintenance therapy with nilotinib, 6-MP, MTX and DEX/VCR boosts. Stem cell transplantation (SCT) was permitted as considered appropriate. BCR-ABL1 RTQ-PCR and kinase domain resistance mutations were centrally monitored. Primary endpoint was event-free survival (EFS) at 12 months, secondary endpoints included rates of CR, major and complete molecular response, relapse free survival (RFS), EFS and overall survival (OS).Results. 72/79 enrolled pts. were evaluable for response, 3 withdrew consent, 4 did not meet eligibility criteria. Median age was 65.5 (55-85) years, male/female ratio 0.85, ECOG status 0 or 1 in 89% of pts., median CIRS comorbidity score 5(0-19). Baseline vascular risk factors including high blood pressure (grade ≥2) were present in 36% of pts.. Sixty-eight of 72 pts. (94.4%) achieved CR, one died during induction and one was refractory, 2 pts. discontinued study therapy. Non-hematologic adverse events (AE) grades 3/4 during induction (in ≥ 5% of pts. irrespective of causality) included infections (n=20), elevated transaminases or bilirubin (n=18) and gastrointestinal AEs (n=12). The spectrum of AEs was similar during consolidation, without concerns related to cardiovascular events. 24 pts. (61y; 55-69y) underwent allogeneic (9 MUD, 12 SIB, 3 Haplo) and 3 autologous SCT. 21 pts. received reduced intensity conditioning (including 8Gy TBI, n=11) regimens. Among all pts., relapse was the main cause of treatment failure (n=23; 17 BM, 2 CNS, 3 other sites, 1 na), 11 pts. died in CR (6 after HSCT), 34 are in ongoing CR. Based on Kaplan Meier analysis, EFS (events being resistant disease, relapse or death) at 12 months was 74%, with median follow-up of 39 (24-66) months for surviving pts., EFS and OS at 4 years was 42%, and 47%, respectively. By landmark analyses using median time to HSCT as cutoff, cumulative incidence of relapse in transplanted vs. non-transplanted pts. was 32% and 47%, OS at 4 years was 61% and 39%, median OS was not reached versus 3.6 years, respectively (p=ns). The proportion of pts. with a BCR-ABL1/ABL1 ratio ≤0.1% increased from 41% after induction to 86% after consolidation 2; that of pts. with undetectable or non-quantifiable BCR-ABL1 transcripts (sensitivity ≥10-4) increased from 14% to 58%.Conclusions. Nilotinib combined with low-intensity chemotherapy is well tolerated and highly effective in elderly pts. with Ph-positive ALL. OS and EFS compare favorably with previous similar studies testing imatinib or dasatinib. With 32% of pts. undergoing allogeneic HSCT and 61% survival at 4 years, transplantation is a viable option in this elderly cohort of pts.. DisclosuresOttmann:Celgene: Consultancy, Research Funding; Novartis: Consultancy; Incyte: Consultancy, Research Funding; Takeda: Consultancy; Amgen: Consultancy; Pfizer: Consultancy; Fusion Pharma: Consultancy, Research Funding. Pfeifer:Novartis: Research Funding. Cayuela:Cepheid: Other: financial sponsor to attend John Goldman Conference 2017. Viardot:Roche: Consultancy, Honoraria; Amgen: Consultancy; Gilead Kite: Consultancy, Honoraria; BMS: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria. Sanhes:Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Goekbuget:Pfizer: Consultancy, Other: Travel support, Research Funding; Novartis: Consultancy, Other: Travel support, Research Funding; Celgene: Consultancy; Kite / Gilead: Consultancy; Amgen: Consultancy, Other: Travel support, Research Funding. Dombret:Jazz Pharma: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria; Astellas: Consultancy, Honoraria; Menarini: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria; Sunesis: Consultancy, Honoraria; Ambit (Daiichi Sankyo): Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Research Funding; Agios: Consultancy, Honoraria; Kite Pharma: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding, Speakers Bureau; Abbvie: Consultancy, Honoraria; Roche/Genentech: Consultancy, Honoraria; Servier: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Ariad (Incyte): Consultancy, Honoraria, Other: Travel expenses, Research Funding, Speakers Bureau; Shire-Baxalta: Consultancy, Honoraria; Immunogen: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Other: Travel expenses, Speakers Bureau; Cellectis: Consultancy, Honoraria, Other: Travel expenses; Otsuka: Consultancy, Honoraria; Amgen: Consultancy, Honoraria, Other: Travel expenses, Research Funding, Speakers Bureau.