Entospletinib (ENTO) and Decitabine (DEC) Combination Therapy in Older Newly Diagnosed (ND) Acute Myeloid Leukemia (AML) Patients with Mutant TP53 or Complex Karyotype Is Associated with Poor Response and Survival: A Phase 2 Sub-Study of the Beat AML Master Trial
Authors: Duong Vu H. , Ruppert Amy S. , Mims Alice S. , Borate Uma , Stein Eytan M. , Baer Maria R. , Stock Wendy , Kovacsovics Tibor , Blum William G. , Arellano Martha L. , Schiller Gary J. , Olin Rebecca L. , Foran James M. , Litzow Mark R. , Lin Tara L. , Patel Prapti A. , Foster Matthew C. , Redner Robert L. , Al-Mansour Zeina , Cogle Christopher R. , Swords Ronan T. , Collins Robert H. , Vergilio Jo-Anne , Heerema Nyla A. , Rosenberg Leonard , Yocum Ashley O. , Marcus Sonja , Chen Timothy , Druggan Franchesca , Stefanos Mona , Gana Theophilus J , Shoben Abigail B. , Druker Brian J. , Burd Amy , Byrd John C. , Levine Ross L. , Boyiadzis Michael M. 
Published: November 2021

Abstract
Background: In vitro studies and emerging clinical data suggest that inhibition of spleen tyrosine kinase may have an antileukemic effect in human AML. Pts with AML and TP53 mutations (TP53m) are commonly associated with older age (≥60 years) and complex karyotype (CK) and respond poorly to standard 7 + 3 induction (IND) chemotherapy with &lt;10% 1-year overall survival (OS). DEC has been reported to improve response in TP53m AML. Here, we report the results of a Phase 2 sub-study of the Beat AML Master Trial that assessed the efficacy of ENTO + DEC combination treatment (Tx) in ND AML patients (pts) with TP53m or CK aged ≥60 years. [ClinicalTrials.gov: NCT03013998]
Methods: This multicenter (13 sites), open-label, Phase 2 combination Tx study utilized Simon's 2-stage Phase 2 design and enrolled AML pts with TP53m (identified molecularly) ± CK (Cohort A) or CK (≥3 metaphase abnormalities) without TP53m (Cohort B). Pts initially received 5 days of ENTO lead-in (which was later discontinued), followed by ENTO + DEC and those who achieved CR/CRh/CRi/MLFS with up to 3 cycles of IND proceeded to consolidation (CON) Tx for up to 11 cycles (Figure 1). Pts with CRi/MLFS after IND were allowed up to 6 cycles (IND + CON) to achieve CR/CRh or stayed on Tx if they got clinical benefit or went off Tx. CON was followed by maintenance (MTN) Tx for up to 2 years from start of study Tx. Pts were eligible if aged ≥60 years, ND, and had ECOG performance status 0 - 2. Pts received ENTO 400 mg orally twice daily for 5 days during ENTO lead-in, and then every 28 days during IND, CON, and MTN + DEC 20 mg/m 2 IV days 1-10 (IND) or days 1-5 (CON) every 28 days. Response was assessed using modified 2017 ELN AML criteria. The primary endpoint was composite complete remission (CCR) rate (CR + CRh) with up to 3 cycles of IND, and CRi/MLFS that achieved CR/CRh by up to 6 cycles (IND + CON). Beyond stage 1, pt accrual to Cohort A was allowed based on pts with CRi and to Cohort B was stopped early for futility.
Results: Between Oct 2017 and Feb 2020, of the 63 pts enrolled (Cohort A = 48; Cohort B = 15), pts with confirmed eligibility who started study Tx were included in the analyses (Cohort A = 45; Cohort B = 13). During lead-in, 27 pts in Cohort A and 6 pts in Cohort B received ENTOm for 5 days. All pts received ENTO + DEC except 1 pt in Cohort A who withdrew consent (WOC). Median ages of the pts were 70 years (range 60 - 84) in Cohort A and 74 years (range 65 - 86) in Cohort B. Median time (range) on Tx was 2.2 mos and 4.8 mos in Cohort A and B, respectively. Most common reasons for Tx discontinuation were adverse event (AE; 27%), Tx failure (TF; 27%) and WOC (18%) in Cohort A; TF (31%), disease progression and relapse (each 15%) in Cohort B. In each cohort, 1 pt discontinued Tx due to death from leukemia and 1 pt in Cohort A in CRh due to development of an additional genetic abnormality. Four pts (9%) in Cohort A and 1 pt (8%) in Cohort B proceeded to transplant.
The CCR (CR + CRh) rates with up to 6 cycles of Tx for Cohort A and B were 13.3% and 30.8%, respectively; overall CR + CRh rates were 17.8% and 38.5% (Table 1). In Cohort A, with a median follow-up of 11.5 months, 0% were 1-year disease-free and median OS (mOS) was 6.5 months. In Cohort B, with a median follow-up of 15.1 months, 25% were 1-year disease-free and mOS was 11.5 months. Deaths within 7-, 30-, and 60-days of Tx were 0, 3 and 11 in Cohort A and 0, 0 and 2 in Cohort B.
Most common treatment-related Grade ≥3 AEs in Cohort A and B were febrile neutropenia (31% and 39%) and anemia (22% and 31%) (Table 2). Overall, 83 serious AEs (SAEs) were reported in 33 pts in Cohort A and 12 SAEs in 6 pts in Cohort B; most common SAEs in Cohort A were pneumonia (18%) and respiratory failure (11%), and in Cohort B sepsis, dehydration and acute kidney injury (each 15%). Most common treatment-related grade ≥3 laboratory abnormalities in Cohort A and B were neutrophils decreased (27% and 31%), WBC count decreased (20% and 23%), and lymphocyte count decreased (18% and 15%).
Conclusions: ENTO + DEC demonstrated activity in ND AML pts aged ≥60 years with TP53m ± CK and CK without TP53 but induced low CR/CRh rates and short OS consistent with previously published poor CR rates and OS in these pts. Our results differ from the high remission rate and longer OS previously reported for DEC monotherapy in AML pts with TP53m. ENTO + DEC was safe and acceptably tolerated. Novel Tx strategies that can benefit AML pts with these most adverse risk factors are urgently needed.
Figure 1 Figure 1.

Disclosures
Ruppert: Telios Pharma: Consultancy. Mims: Leukemia and Lymphoma Society's Beat AML clinical study: Consultancy, Research Funding; Aptevo: Research Funding; Daiichi Sankyo: Consultancy, Research Funding; Glycomemetics: Research Funding; Kartos Pharmaceuticals: Research Funding; Xencor: Research Funding; Genentech: Consultancy; Abbvie: Consultancy; BMS: Consultancy; Kura Oncology: Consultancy; Syndax Pharmaceuticals: Consultancy; BMS: Consultancy; Jazz Pharmaceuticals: Consultancy; Aptevo: Research Funding. Borate: Jazz Pharma: Research Funding; Daiichi-Sankyo: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; Blueprint Medicine: Membership on an entity's Board of Directors or advisory committees; Genentech: Membership on an entity's Board of Directors or advisory committees, Other: Advisory Board; Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Astellas: Membership on an entity's Board of Directors or advisory committees; incyte: Membership on an entity's Board of Directors or advisory committees, Research Funding; Rampal: Membership on an entity's Board of Directors or advisory committees; Galecto, Inc.: Consultancy; Promedior: Consultancy. Stein: Abbvie: Consultancy; Janssen Pharmaceuticals: Consultancy; Gilead Sciences, Inc.: Consultancy; Foghorn Therapeutics: Consultancy; Syros Pharmaceuticals, Inc.: Consultancy; Daiichi Sankyo: Consultancy; Blueprint Medicines: Consultancy; PinotBio: Consultancy; Genentech: Consultancy; Jazz Pharmaceuticals: Consultancy; Bristol Myers Squibb: Consultancy; Celgene: Consultancy; Agios Pharmaceuticals, Inc: Consultancy; Novartis: Consultancy; Astellas: Consultancy; Syndax Pharmaceuticals: Consultancy. Stock: Pfizer: Consultancy, Honoraria, Research Funding; amgen: Honoraria; agios: Honoraria; jazz: Honoraria; kura: Honoraria; kite: Honoraria; morphosys: Honoraria; servier: Honoraria; syndax: Consultancy, Honoraria; Pluristeem: Consultancy, Honoraria. Kovacsovics: AbbVie: Research Funding; Janssen Pharmaceuticals: Research Funding; Amgen Inc.: Research Funding; Novartis: Research Funding; Stemline: Honoraria; Jazz Pharmaceutials: Honoraria. Blum: Amerisource Bergen; Abbvie, Syndax: Honoraria; Forma Therapeutics, Xencor; Celyad: Research Funding. Arellano: KITE Pharma, Inc: Consultancy; Syndax Pharmaceuticals, Inc: Consultancy. Schiller: Actinium Pharmaceuticals, Inc: Research Funding; Gamida Cell Ltd.: Research Funding; Pfizer: Current equity holder in publicly-traded company, Research Funding; Forma: Research Funding; Agios: Consultancy, Research Funding, Speakers Bureau; Constellation Pharmaceuticals: Research Funding; MedImmune: Research Funding; Ambit: Research Funding; Karyopharm: Research Funding; Daiichi-Sankyo: Research Funding; Incyte: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Kaiser Permanente: Consultancy; Abbvie: Research Funding; AstraZeneca: Consultancy; Genentech-Roche: Research Funding; Delta-Fly: Research Funding; Cyclacel: Research Funding; Mateon: Research Funding; Actuate: Research Funding; Onconova: Research Funding; Geron: Research Funding; Sangamo: Research Funding; Arog: Research Funding; Ariad: Research Funding; Stemline Therapeutics, Inc.: Honoraria, Research Funding, Speakers Bureau; Takeda: Research Funding; Trovagene: Research Funding; Ono-UK: Consultancy, Research Funding; Tolero: Research Funding; BMS/Celgene: Consultancy, Current equity holder in publicly-traded company, Research Funding, Speakers Bureau; Celator: Research Funding; Kite/Gilead: Honoraria, Research Funding, Speakers Bureau; Astellas: Honoraria, Research Funding, Speakers Bureau; Incyte: Consultancy; Novartis: Consultancy, Research Funding; Deciphera: Research Funding; FujiFilm: Research Funding; Samus: Research Funding; Regimmune: Research Funding; PrECOG: Research Funding; Amgen: Consultancy, Current equity holder in publicly-traded company, Honoraria, Research Funding, Speakers Bureau; Bio: Research Funding; Elevate: Research Funding; Jazz: Consultancy, Honoraria, Research Funding, Speakers Bureau; Biomed Valley Discoveries: Research Funding; Ono: Consultancy; Eli Lilly: Research Funding; Sellas: Research Funding; ASH foundation: Other: Chair-unpaid; Leukemia & Lymphoma Society: Research Funding; Bluebird Bio: Research Funding; Sanofi: Honoraria, Research Funding, Speakers Bureau; Pharma: Consultancy; Johnson & Johnson: Current equity holder in publicly-traded company; Boehringer-Ingleheim: Research Funding; Cellerant: Research Funding; CTI Biopharma: Research Funding; Janssen: Research Funding; Kura Oncology: Research Funding; Pharmacyclics: Honoraria, Speakers Bureau; Millennium: Research Funding; National Marrow Donor Program: Research Funding; NIH: Research Funding; Onyx: Research Funding; Pharmamar: Research Funding; UC Davis: Research Funding; UCSD: Research Funding; Evidera: Consultancy; NCI: Consultancy; Novartis: Speakers Bureau. Olin: Astellas: Honoraria, Research Funding; Actinium: Honoraria; Amgen: Honoraria; Abbvie: Honoraria; Cellectis: Research Funding; Daiichi Sankyo: Research Funding; Genentech: Research Funding; Pfizer: Research Funding. Foran: certara: Honoraria; pfizer: Honoraria; syros: Honoraria; taiho: Honoraria; boehringer ingelheim: Research Funding; servier: Honoraria; revolution medicine: Honoraria; trillium: Research Funding; takeda: Research Funding; abbvie: Research Funding; novartis: Honoraria; bms: Honoraria; OncLive: Honoraria; gamida: Honoraria; sanofi aventis: Honoraria; aptose: Research Funding; actinium: Research Funding; kura: Research Funding; h3bioscience: Research Funding; aprea: Research Funding; sellas: Research Funding; stemline: Research Funding. Litzow: AbbVie: Research Funding; Omeros: Other: Advisory Board; Astellas: Research Funding; Pluristem: Research Funding; Jazz: Other: Advisory Board; Actinium: Research Funding; Amgen: Research Funding; Biosight: Other: Data monitoring committee. Lin: AbbVie, Aptevo Therapeutics, Astellas Pharma, Bio-Path Holdings, Celgene, Celyad, Genentech-Roche, Gilead Sciences, Incyte, Jazz Pharmaceuticals, Novartis, Ono Pharmaceutical, Pfizer, Prescient Therapeutics, Seattle Genetics, Tolero, Trovagene: Research Funding. Cogle: Aptevo therapeutics: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees. Vergilio: Foundation Medicine: Current Employment; Roche: Current equity holder in publicly-traded company. Gana: Bausch: Current holder of individual stocks in a privately-held company; The Leukemia & Lymphoma Society: Consultancy. Druker: The RUNX1 Research Program: Membership on an entity's Board of Directors or advisory committees; Aileron: Membership on an entity's Board of Directors or advisory committees; Novartis Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Patents & Royalties; Recludix Pharma, Inc.: Consultancy; Third Coast Therapeutics: Membership on an entity's Board of Directors or advisory committees; Vincerx Pharma: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; VB Therapeutics: Membership on an entity's Board of Directors or advisory committees; GRAIL: Current equity holder in publicly-traded company; Iterion Therapeutics: Membership on an entity's Board of Directors or advisory committees; ALLCRON: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Aptose Therapeutics: Consultancy, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Blueprint Medicines: Consultancy, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Research Funding; EnLiven: Consultancy, Research Funding; Merck & Co: Patents & Royalties; Pfizer: Research Funding; Nemucore Medical Innovations, Inc.: Consultancy; Cepheid: Consultancy, Membership on an entity's Board of Directors or advisory committees; Vivid Biosciences: Membership on an entity's Board of Directors or advisory committees. Byrd: Vincerx Pharmaceuticals: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Novartis, Trillium, Astellas, AstraZeneca, Pharmacyclics, Syndax: Consultancy, Honoraria; Newave: Membership on an entity's Board of Directors or advisory committees. Levine: Isoplexis: Membership on an entity's Board of Directors or advisory committees; Gilead: Honoraria; Zentalis: Membership on an entity's Board of Directors or advisory committees; Imago: Membership on an entity's Board of Directors or advisory committees; Ajax: Membership on an entity's Board of Directors or advisory committees; Lilly: Honoraria; Prelude: Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria; Janssen: Consultancy; Celgene: Research Funding; Roche: Honoraria, Research Funding; Auron: Membership on an entity's Board of Directors or advisory committees; C4 Therapeutics: Membership on an entity's Board of Directors or advisory committees; Incyte: Consultancy; Astellas: Consultancy; Morphosys: Consultancy; QIAGEN: Membership on an entity's Board of Directors or advisory committees; Mission Bio: Membership on an entity's Board of Directors or advisory committees.

OffLabel Disclosure:
Off-label use of entospletinib and decitabine.