ALBERT

Beschreibung: Activating mutations in FLT3 confer poor prognosis for individuals with acute myeloid leukemia (AML). Clinically active investigational FLT3 inhibitors can achieve complete remissions but their utility has been hampered by acquired resistance and myelosuppression attributed to a ‘synthetic lethal toxicity’ arising from simultaneous inhibition of FLT3 and KIT. We report a novel chemical strategy for selective FLT3 inhibition while avoiding KIT inhibition with the staurosporine analog, Star 27. Star 27 maintains potency against FLT3 in proliferation assays of FLT3-transformed cells compared with KIT-transformed cells, shows no toxicity towards normal human hematopoiesis at concentrations that inhibit primary FLT3-mutant AML blast growth, and is active against mutations that confer resistance to clinical inhibitors. As a more complete understanding of kinase networks emerges, it may be possible to define anti-targets such as KIT in the case of AML to allow improved kinase inhibitor design of clinical agents with enhanced efficacy and reduced toxicity.

Beschreibung: Background: Treatment of chronic myeloid leukemia (CML) with a tyrosine kinase inhibitor (TKI) offers significant improvements over previous treatments in terms of survival and toxicity yet has been associated with reduced health-related quality of life and very high cost. Discontinuing TKIs with regular monitoring is safe, but little is known about the impact of discontinuation on patient-reported outcomes (PROs). In the largest U.S. study to date, we evaluated molecular recurrence of CML and PROs after TKI discontinuation. Methods: The Life After Stopping TKIs (LAST) study was a prospective single-group longitudinal study. Key inclusion criteria were age 〉 18 years, patient on TKI therapy (imatinib, dasatinib, nilotinib, or bosutinib) for 〉 3 years with documented BCR-ABL 〈 0.01% by PCR for 〉 2 years, and no previous TKI resistance. We monitored disease outcome (PCRs by central lab) and PROs (PROMIS computerized adaptive tests via REDCap) monthly for the first 6 months, every 2 months until 24 months, then every 3 months until 36 months. Molecular recurrence was defined as 〉 0.1% BCR-ABL IS by central lab (loss of major molecular response [MMR]). We considered 3 points to be clinically meaningful and hypothesized that by 6 months after TKI discontinuation, fatigue, depression, sleep disturbance, and diarrhea would improve by at least 3 points each, corresponding to a standardized effect size of 0.3. Given reports of a withdrawal syndrome of musculoskeletal pain in some patients after discontinuation, pain was an additional outcome of particular interest. For each PRO domain, we estimated a polynomial piecewise linear mixed effects model that specified one nonlinear trajectory after TKI discontinuation and, for those with molecular recurrence, another trajectory after TKI restart. The models included patient-level random effects for the intercepts and linear slopes. Results: From 12/2014 to 12/2016, 172 patients enrolled from 14 U.S. sites. Median age was 60 years (range 21-86) and 89 (52%) were female. The median time on TKI prior to enrollment was 81 months (IQR 54-123). With a minimum follow-up of 24 months, 107 (62%) patients remained in a treatment free remission (TFR). Reasons for restarting therapy were: loss of MMR by central (n=56) or local (n=2) lab, patient decision (n=4), and withdrawal syndrome (n=3). Missing PRO data was minimal (〈 5%) with 〉 2000 assessments completed. For patients in TFR at 6 months, the average estimated improvement in fatigue was 2.6 points (95% CI 2.5-2.7), depression was 1.9 points (95% CI 1.8-1.9), sleep disturbance was 0.9 points (95% CI 0.8-1.0), and diarrhea was 2.7 points (95% CI 2.6-2.7). The average estimated worsening in pain interference (i.e., the extent to which pain affects daily life) was 0.4 points (95% CI 0.3-0.5). The figure shows the distribution of estimated change for each domain at 6 months. All patients showed improvements in depression, diarrhea, and fatigue. About 1 in 6 patients (17%) experienced a clinically meaningful (i.e., at least 3 points) improvement in fatigue and/or diarrhea at 6 months. Conclusion: The LAST study is the largest US TKI discontinuation study to date, and the first to include comprehensive PRO measurement. For patients in TFR at 6 months, TKI discontinuation conferred modest benefits in fatigue and diarrhea on average, with a negligible increase in pain interference. Some patients experienced more notable improvements in fatigue and diarrhea. Planned secondary analyses will include change over time up to 3 years and evaluation of additional PRO domains, including anxiety, physical function, social function, and sexual function. Our results provide important new evidence to support shared patient-provider clinical decision making regarding TKI discontinuation for patients with CML. Figure. Disclosures Radich: Novartis: Other: RNA Sequencing; TwinStrand Biosciences: Research Funding. Mauro:Pfizer: Consultancy; Takeda: Consultancy; Novartis Oncology: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy. Pinilla Ibarz:Sanofi: Speakers Bureau; Abbvie: Consultancy, Speakers Bureau; Teva: Consultancy; Janssen: Consultancy, Speakers Bureau; Novartis: Consultancy; Takeda: Consultancy, Speakers Bureau; Bayer: Speakers Bureau; TG Therapeutics: Consultancy; Bristol-Myers Squibb: Consultancy. Larson:Celgene: Consultancy; Novartis: Honoraria, Other: Contracts for clinical trials; Agios: Consultancy. Oehler:Blueprint Medicines: Consultancy; NCCN: Consultancy; Pfizer Inc.: Research Funding. Deininger:Humana: Honoraria; Incyte: Honoraria; Blueprint: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Honoraria, Research Funding; Ascentage Pharma: Consultancy, Honoraria; TRM: Consultancy; Sangoma: Consultancy; Fusion Pharma: Consultancy; Adelphi: Consultancy; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria; Sangamo: Consultancy. Shah:Bristol-Myers Squibb: Research Funding. Ritchie:Tolero: Other: Advisory board; Celgene: Other: Advisory board; Celgene, Novartis: Other: travel support; Jazz Pharmaceuticals: Research Funding; Celgene, Incyte, Novartis, Pfizer: Consultancy; AStella, Bristol-Myers Squibb, Novartis, NS Pharma, Pfizer: Research Funding; Ariad, Celgene, Incyte, Novartis: Speakers Bureau; Genentech: Other: Advisory board; Pfizer: Other: Advisory board, travel support; agios: Other: Advisory board. Silver:PharmEssentia: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Cortes:Sun Pharma: Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; Forma Therapeutics: Consultancy, Honoraria, Research Funding; BiolineRx: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Daiichi Sankyo: Consultancy, Honoraria, Research Funding; Jazz Pharmaceuticals: Consultancy, Research Funding; Biopath Holdings: Consultancy, Honoraria; Immunogen: Consultancy, Honoraria, Research Funding; Merus: Consultancy, Honoraria, Research Funding; Astellas Pharma: Consultancy, Honoraria, Research Funding. Atallah:Jazz: Consultancy; Helsinn: Consultancy; Pfizer: Consultancy; Takeda: Consultancy, Research Funding; Jazz: Consultancy; Helsinn: Consultancy; Novartis: Consultancy.

Beschreibung: The optimal management of patients with chronic myeloid leukemia (CML) is increasingly reliant upon molecular studies. Loss of response to imatinib in CML is most commonly associated with selection for a limited number of BCR-ABL kinase domain mutations that impair the ability of imatinib to effectively bind to BCR-ABL Molecular understanding of imatinib resistance mechanisms has led to the development of effective “second generation” BCR-ABL kinase inhibitors, such as dasatinib and nilotinib, which have clinical activity against most, but not all, drug-resistant mutations. Analysis of the BCR-ABL kinase domain in patients who develop resistance to second-generation inhibitors has implicated further selection of drug-resistant BCR-ABL kinase domain mutants in nearly all cases reported to date. Encouragingly, the number of resistant mutations capable of conferring clinical resistance to the most clinically-advanced second-generation agents, dasatinib (approved by the US FDA and EMEA) and nilotinib (approved in Mexico and Switzerland), appears to be restricted to a relatively small number of amino acid substitutions. As clinical experience with dasatinib and nilotinib grows, an understanding of the relative sensitivities of dasatinib- and nilotinib-resistant BCR-ABL mutants to other kinase inhibitors, both approved and investigational, is critical to optimize clinical outcomes in patients with resistance to dasatinib or nilotinib. At the present time, kinase inhibitor therapy options for patients with resistance to one of these agents include the investigational options bosutinib and MK-0457 (VX-680), as well as dasatinib and nilotinib (for patients not yet exposed to one of these agents) and re-exposure imatinib. It is likely that the success of therapeutic intervention in these cases can be predicted based upon the preclinical sensitivity of the mutation(s) involved with the agent chosen. We have therefore conducted a thorough biochemical and biological cross-analysis of the activities of each of these clinically-useful kinase inhibitors against mutations that confer clinical resistance to dasatinib or nilotinib. These studies provide clinicians with a useful reference for choosing an appropriate kinase inhibitor based upon the identity of the resistant BCR-ABL kinase domain mutation(s) detected at the time of relapse when faced with a patient who has lost response to dasatinib or nilotinib. It is hoped that the application of such “personalized medicine” strategies to the clinical management of CML cases will further improve outcomes in patients treated with kinase inhibitor therapy.

Beschreibung: Background The efficacy and safety of subsequent TKIs in pts who have experienced failure of dasatinib is not fully known. Ponatinib, a pan-BCR-ABL inhibitor, was evaluated in a phase 2, international, open-label clinical trial (PACE). This post-hoc analysis explored the efficacy and safety of ponatinib following failure of dasatinib in CP-CML pts in the PACE trial. Methods The PACE trial enrolled 449 pts, including 270 with CP-CML. Pts had to be resistant or intolerant to dasatinib or nilotinib, or they had to have the T315I mutation at baseline. The primary endpoint in CP-CML was major cytogenetic response (MCyR) at any time within 12 months after treatment initiation. The trial is ongoing. Data as of 1 April 2013 are reported, with a minimum follow-up of 18 months for pts remaining on study. The efficacy and safety of ponatinib (45 mg QD) in 107 CP-CML pts following failure of dasatinib as the most recent prior therapy, irrespective of other TKI therapy, is presented (Group D). Eighteen pts who experienced failure of dasatinib but received ≥1 anticancer therapy, other than hydroxyurea or anagrelide, prior to ponatinib treatment were excluded from the analyses. Data are also presented for 2 subsets of Group D: 52 pts whose only TKI therapy was imatinib followed by dasatinib (Group I-D), and 46 pts whose only TKI therapy was imatinib, then nilotinib, and then dasatinib (Group I-N-D). An analysis of cross-intolerance was also conducted in 69 pts with prior dasatinib treatment at any time who discontinued dasatinib due to intolerance. Results Baseline characteristics are shown in the table. Group I-D tended to be younger, with less time since diagnosis versus Group I-N-D. At the time of analysis, 60%, 65%, and 54% of pts in Groups D, I-D, and I-N-D remained on study. The most common reasons for discontinuation were adverse events (AEs; 16%, 15%, 17%) and progressive disease (9%, 6%, 11%) in Groups D, I-D, and I-N-D. Efficacy end points are shown in the table. In Group D, MCyR was seen in pts with the following dasatinib-resistant mutations at baseline: V299L, 3/4 (75%); T315I, 17/23 (74%); F317L, 3/10 (30%). The most common treatment-related AEs were thrombocytopenia (44%, 37%, 57%), rash (39%, 39%, 39%), and dry skin (39%, 29%, 52%) in Groups D, I-D, and I-N-D. Serious cardiovascular, cerebrovascular, and peripheral vascular AEs occurred in 6%, 3%, and 3% of pts in Group D (treatment-related: 3%, 1%, 0%). Seventy-three of 217 pts receiving prior dasatinib at any time discontinued dasatinib due to intolerance. Of these 73 pts, 27 experienced the same AE(s) with ponatinib that led to dasatinib intolerance; 12 pts had grade 3/4 thrombocytopenia, 6 pts had other grade 3/4 AEs (3 with neutropenia, 1 each with pleural effusion, dyspnea, pulmonary hypertension), 8 pts had grade 1/2 AEs. Six of these 27 pts discontinued ponatinib due to the same AE that led to dasatinib intolerance. Thrombocytopenia was the primary AE involved in cross-intolerance (4 pts); congestive cardiac failure (grade 5) and pleural effusion each occurred once. Conclusions Ponatinib has substantial activity in pts with CP-CML following failure of dasatinib, with a safety profile reflective of this heavily pretreated population. Cross-intolerance between dasatinib and ponatinib was infrequent. Disclosures: Hochhaus: Ariad, Novartis, BMS, MSD, Pfizer: Research Funding; Novartis, BMS, Pfizer: Honoraria. Cortes:Ariad, Pfizer, Teva: Consultancy; Ariad, BMS, Novartis, Pfizer, Teva: Research Funding. Kim:BMS, Novartis,IL-Yang: Consultancy; BMS, Novartis, Pfizer,ARIAD,IL-Yang: Research Funding; BMS, Novartis,Pfizer,IL-Yang: Honoraria; BMS, Novartis,Pfizer: Speakers Bureau; BMS, Pfizer: Membership on an entity’s Board of Directors or advisory committees. Pinilla-Ibarz:Novartis, Ariad: Research Funding; Novartis, Ariad, BMS and Pfizer: Speakers Bureau. le Coutre:Novartis: Research Funding; Novatis, BMS, Pfizer: Honoraria. Paquette:ARIAD, BMS, Novartis: Consultancy, Honoraria, Speakers Bureau. Chuah:Novartis, Bristol-Myers Squibb: Honoraria. Nicolini:Novartis, Ariad and Teva: Consultancy; Novartis & Bristol Myers Squibb: Research Funding; Novartis, BMS, Teva, Pfizer, Ariad: Honoraria; Novartis, BMS, Teva: Speakers Bureau; Novartis, Ariad, Teva, Pfizer: Membership on an entity’s Board of Directors or advisory committees. Apperley:Novartis: Research Funding; Ariad, Bristol Myers Squibb, Novartis, Pfizer, Teva: Honoraria. Talpaz:Ariad, BMS, Sanofi, INCYTE: Research Funding; Ariad, Novartis: Speakers Bureau; Ariad, Sanofi, Novartis: Membership on an entity’s Board of Directors or advisory committees. DeAngelo:Araid, Novartis, BMS: Consultancy. Abruzzese:BMS, Novartis: Consultancy. Rea:BMS, Novartis, Pfizer, Ariad, Teva: Honoraria. Baccarani:Ariad, Novartis, BMS: Consultancy; Ariad, Novartis, BMS, Pfizer, Teva: Honoraria, Speakers Bureau. Müller:Novartis, BMS, Ariad: Consultancy, Honoraria; Novartis, BMS: Research Funding. Gambacorti-Passerini:Pfizer: Research Funding; Pfizer, BMS: Honoraria. Lustgarten:ARIAD: employees of and own stock/stock options in ARIAD Pharmaceuticals, Inc Other, Employment. Rivera:ARIAD: Employment. Clackson:ARIAD: employees of and own stock/stock options in ARIAD Pharmaceuticals, Inc Other, Employment. Turner:ARIAD: Employment. Haluska:ARIAD: employees of and own stock/stock options in ARIAD Pharmaceuticals, Inc Other, Employment. Deininger:BMS, ARIAD, NOVARTIS: Consultancy; BMS, NOVARTIS, CELGENE, GILEAD: Research Funding; ARIAD, NOVARTIS: Advisory Boards, Advisory Boards Other. Hughes:Novartis, BMS, ARIAD: Honoraria, Research Funding. Goldman:Ariad: Honoraria. Shah:Ariad, Bristol-Myers Squibb: Consultancy, Research Funding. Kantarjian:RIAD, Novartis, BMS, Pfizer: Research Funding.