Introduction:

Outcome of patients (pts) with CD20-positive B-cell acute lymphoblastic leukemia (B-ALL) has significantly improved with hyper-CVAD (HCVAD) in combination with rituximab with 3-year OS 65% (Thomas et al Blood 2009). Ofatumumab is an anti-CD20 monoclonal antibody with higher capacity of promoting complement-dependent cytotoxicity compared to rituximab. The aim of this study is to compare the outcome of pts with CD20-positive B-ALL who received HCVAD plus ofatumumab (HCVAD-O) or HCVAD plus rituximab (HCVAD-R) therapy.

Methods:

We reviewed 69 adult pts with newly diagnosed, Philadelphia chromosome (Ph)-negative, CD20-positive B-ALL who were treated with HCVAD-O at our institution between 8/2011 and 5/2017. HCVAD therapy consisted of 4 alternating cycles of hyper-fractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone, plus high-dose methotrexate (MTX) / cytarabine (AraC) with 8 intrathecal injections of MTX/AraC. Ofatumumab was administered at 300mg IV as first dose, and 2000mg IV subsequently. The maintenance phase consisted of 30 cycles of 6-MP, MTX, vincristine, and prednisone (POMP) with 4 intensification courses (high-dose MTX plus L-asparaginase and HCVAD+O) on courses 6-7 and 18-19. Overall survival (OS) was calculated from the start date of treatment to the date of death, or last follow-up. We performed a comparison of survival between pts treated with HCVAD-O and a cohort of 153 historical-control pts treated with HCVAD with or without rituximab between 11/2002 and 7/2012. Historical-control pts were treated with HCVAD alone (N=58) if CD20 expression was 1-19% or HCVAD-R (N=95) if CD20 expression was ≥20%. To adjust for baseline differences of pts characteristics between the cohorts, we performed inverse probability of treatment weighing (IPTW) using propensity scores calculated from pts baseline characteristics. Covariates for the calculation of propensity scores included age, performance status, white blood cell count at diagnosis, the positivity of CD20 expression and adverse-risk cytogenetics (KMT2A-rearrangement, complex karyotype or low-hypodiploidy / near triploidy).

Results:

The median follow-up for HCVAD-O cohort and historical-control cohort was 44 months (95% CI: 41-53) and 133 months (95% CI: 115-141), respectively. There was no difference in baseline characteristics between HCVAD-O cohort and historical-control cohort (Table 1). The 5-year OS rates were 65% and 51% in HCVAD-O cohort and historical-control cohort, respectively. With the IPTW analysis, the HCVAD-O regimen was associated with better outcome compared with the historical HCVAD/HCVAD-R regimen (HR, 0.74; 95% CI, 0.55-0.99, p = 0.047) (Figure 1). The treatment effect was similar regardless of the level of CD20 positivity, although not statistically significant among each subgroup (CD20 ≥20%, HR 0.73, 95% CI, 0.52-1.04, p = 0.09; CD20 1-19%, HR, 0.68; 95% CI, 0.39-1.20, p = 0.18).

Conclusions:

The combination of HCVAD plus ofatumumab is highly effective and seems to have offered better outcome than did HCVAD plus rituximab therapy in pts with Ph-negative CD20-positive B-ALL. Additional novel monoclonal/bispecific antibody constructs targeting CD19 and CD22 are expected to further improve the outcome.

Disclosures

Sasaki:Otsuka: Honoraria; Daiichi Sankyo: Consultancy; Pfizer Japan: Consultancy; Novartis: Consultancy, Research Funding. Konopleva:F. Hoffmann La-Roche: Consultancy, Research Funding; Reata Pharmaceutical Inc.;: Patents & Royalties: patents and royalties with patent US 7,795,305 B2 on CDDO-compounds and combination therapies, licensed to Reata Pharmaceutical; Rafael Pharmaceutical: Research Funding; Amgen: Consultancy; Forty-Seven: Consultancy, Research Funding; AstraZeneca: Research Funding; AbbVie: Consultancy, Research Funding; Agios: Research Funding; Ablynx: Research Funding; Cellectis: Research Funding; Genentech: Consultancy, Research Funding; Ascentage: Research Funding; Sanofi: Research Funding; Stemline Therapeutics: Consultancy, Research Funding; Eli Lilly: Research Funding; Kisoji: Consultancy; Calithera: Research Funding. Short:Takeda Oncology: Consultancy, Honoraria, Research Funding; Amgen: Honoraria; Astellas: Research Funding; AstraZeneca: Consultancy. Jain:Pfizer: Research Funding; Cellectis: Research Funding; Aprea Therapeutics: Research Funding; Servier: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BeiGene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Verastem: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; ADC Therapeutics: Research Funding; Adaptive Biotechnologies: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Research Funding; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Precision Bioscienes: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Incyte: Research Funding; Fate Therapeutics: Research Funding; TG Therapeutics: Honoraria, Membership on an entity's Board of Directors or advisory committees. Ravandi:Macrogenics: Research Funding; Astellas: Consultancy, Honoraria, Research Funding; Jazz Pharmaceuticals: Consultancy, Honoraria, Research Funding; AstraZeneca: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Amgen: Consultancy, Honoraria, Research Funding; Xencor: Consultancy, Honoraria, Research Funding; Orsenix: Consultancy, Honoraria, Research Funding; BMS: Consultancy, Honoraria, Research Funding; Abbvie: Consultancy, Honoraria, Research Funding. Daver:Daiichi Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Karyopharm: Research Funding; Servier: Research Funding; Genentech: Research Funding; AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Astellas: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novimmune: Research Funding; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Trovagene: Research Funding; Fate Therapeutics: Research Funding; ImmunoGen: Research Funding; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Jazz: Consultancy, Membership on an entity's Board of Directors or advisory committees; Trillium: Consultancy, Membership on an entity's Board of Directors or advisory committees; Syndax: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees; KITE: Consultancy, Membership on an entity's Board of Directors or advisory committees; Agios: Consultancy, Membership on an entity's Board of Directors or advisory committees. Kadia:Genentech: Honoraria, Research Funding; Cyclacel: Research Funding; Pulmotec: Research Funding; Astellas: Research Funding; Novartis: Honoraria; Celgene: Research Funding; JAZZ: Honoraria, Research Funding; Amgen: Research Funding; BMS: Honoraria, Research Funding; Abbvie: Honoraria, Research Funding; Incyte: Research Funding; Ascentage: Research Funding; Cellenkos: Research Funding; Pfizer: Honoraria, Research Funding; Astra Zeneca: Research Funding. Alvarado:FibroGen: Research Funding; Daiichi-Sankyo: Research Funding; Jazz Pharmaceuticals: Research Funding; Sun Pharma: Research Funding; BerGenBio ASA: Research Funding; MEI Pharma: Research Funding; Tolero Pharmaceuticals: Research Funding; Astex Pharmaceuticals: Research Funding. DiNardo:Agios: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Research Funding; Syros: Honoraria; Calithera: Research Funding; ImmuneOnc: Honoraria; Daiichi Sankyo: Consultancy, Honoraria, Research Funding; Novartis: Consultancy; Takeda: Honoraria; Notable Labs: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Research Funding; MedImmune: Honoraria; Jazz: Honoraria. Issa:Novartis: Membership on an entity's Board of Directors or advisory committees; Syndax: Research Funding; Celegene: Research Funding. Pemmaraju:MustangBio: Honoraria; AbbVie: Honoraria, Research Funding; Pacylex Pharmaceuticals: Consultancy; LFB Biotechnologies: Honoraria; Daiichi Sankyo: Research Funding; Incyte Corporation: Honoraria; Stemline Therapeutics: Honoraria, Research Funding; SagerStrong Foundation: Other: Grant Support; Novartis: Honoraria, Research Funding; Affymetrix: Other: Grant Support, Research Funding; Plexxikon: Research Funding; Celgene: Honoraria; DAVA Oncology: Honoraria; Roche Diagnostics: Honoraria; Cellectis: Research Funding; Blueprint Medicines: Honoraria; Samus Therapeutics: Research Funding. Garcia-Manero:Astex Pharmaceuticals: Consultancy, Honoraria, Research Funding; Amphivena Therapeutics: Research Funding; Onconova: Research Funding; H3 Biomedicine: Research Funding; AbbVie: Honoraria, Research Funding; Novartis: Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Acceleron Pharmaceuticals: Consultancy, Honoraria; Merck: Research Funding; Helsinn Therapeutics: Consultancy, Honoraria, Research Funding; Jazz Pharmaceuticals: Consultancy. Verstovsek:Incyte Corporation: Consultancy, Research Funding; Roche: Research Funding; NS Pharma: Research Funding; Gilead: Research Funding; Genentech: Research Funding; Novartis: Consultancy, Research Funding; ItalPharma: Research Funding; AstraZeneca: Research Funding; PharmaEssentia: Research Funding; CTI Biopharma Corp: Research Funding; Sierra Oncology: Consultancy, Research Funding; Promedior: Research Funding; Blueprint Medicines Corp: Research Funding; Protagonist Therapeutics: Research Funding; Celgene: Consultancy, Research Funding. Champlin:Johnson and Johnson: Consultancy; Actinium: Consultancy; DKMS America: Membership on an entity's Board of Directors or advisory committees; Genzyme: Speakers Bureau; Omeros: Consultancy; Takeda: Patents & Royalties; Cytonus: Consultancy. Khouri:Bristol Myers Squibb: Research Funding; Pfizer: Research Funding. Kebriaei:Novartis: Other: Served on advisory board; Pfizer: Other: Served on advisory board; Amgen: Other: Research Support; Ziopharm: Other: Research Support; Kite: Other: Served on advisory board; Jazz: Consultancy. O'Brien:Kite, Regeneron, Acerta: Research Funding; Gilead, Pharmacyclics, TG Therapeutics, Pfizer, Sunesis: Consultancy, Research Funding; Amgen, Astellas, Celgene, GlaxoSmithKline, Janssen Oncology, Aptose Biosciences Inc. Vaniam Group, AbbVie, Alexion, Verastem, Eisai, Juno Therapeutics, Vida Ventures: Consultancy. Kantarjian:Daiichi-Sankyo: Research Funding; Immunogen: Research Funding; Ariad: Research Funding; Novartis: Research Funding; BMS: Research Funding; Cyclacel: Research Funding; Agios: Honoraria, Research Funding; Jazz Pharma: Research Funding; Takeda: Honoraria; AbbVie: Honoraria, Research Funding; Actinium: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Research Funding; Astex: Research Funding; Pfizer: Honoraria, Research Funding. Jabbour:Pfizer: Other: Advisory role, Research Funding; Adaptive Biotechnologies: Other: Advisory role, Research Funding; BMS: Other: Advisory role, Research Funding; Genentech: Other: Advisory role, Research Funding; Takeda: Other: Advisory role, Research Funding; Amgen: Other: Advisory role, Research Funding; AbbVie: Other: Advisory role, Research Funding.

Author notes

*

Asterisk with author names denotes non-ASH members.