Long-term evaluation of cardiac and vascular toxicity in patients with Philadelphia chromosome-positive leukemias treated with bosutinib.

Vascular and cardiac safety during tyrosine kinase inhibitor (TKI) therapy is an emerging issue. We evaluated vascular/cardiac toxicities associated with long-term bosutinib treatment for Philadelphia chromosome-positive (Ph+) leukemia based on treatment-emergent adverse events (TEAEs) and changes in QTc intervals and ejection fraction in two studies: a phase 1/2 study of second-/third-/fourth-line bosutinib for Ph+ leukemia resistant/intolerant to prior TKIs (N = 570) and a phase 3 study of first-line bosutinib (n = 248) versus imatinib (n = 251) in chronic phase chronic myeloid leukemia. Follow-up time was ≥48 months (both studies). Incidences of vascular/cardiac TEAEs in bosutinib-treated patients were 7%/10% overall with similar incidences observed with first-line bosutinib (5%/8%) and imatinib (4%/6%). Few patients had grade ≥3 vascular/cardiac events (4%/4%) and no individual TEAE occurred in >2% of bosutinib patients. Exposure-adjusted vascular/cardiac TEAE rates (patients with events/patient-year) were low for second-line or later bosutinib (0.037/0.050) and not significantly different between first-line bosutinib (0.015/0.024) and imatinib (0.011/0.017; P ≥ 0.267). Vascular/cardiac events were managed mainly with concomitant medications (39%/44%), bosutinib treatment interruptions (18%/21%), or dose reductions (4%/8%); discontinuations due to these events were rare (0.7%/1.0%). Based on logistic regression modelling, performance status >0 and history of vascular or cardiac disorders were prognostic of vascular/cardiac events in relapsed/refractory patients; hyperlipidemia/hypercholesterolemia and older age were prognostic of cardiac events. In newly diagnosed patients, older age was prognostic of vascular/cardiac events; history of diabetes was prognostic of vascular events. Incidences of vascular and cardiac events were low with bosutinib in the first-line and relapsed/refractory settings following long-term treatment in patients with Ph+ leukemia. Am. J. Hematol. 91:606-616, 2016. © 2016 Wiley Periodicals, Inc.

Long-term bosutinib for chronic phase chronic myeloid leukemia after failure of imatinib plus dasatinib and/or nilotinib.

Bosutinib is an Src/Abl tyrosine kinase inhibitor (TKI) indicated for adults with Ph+ chronic myeloid leukemia (CML) resistant/intolerant to prior TKIs. This long-term update of an ongoing phase 1/2 study evaluated the efficacy and safety of third-/fourth-line bosutinib in adults with chronic phase (CP) CML. Median durations of treatment and follow-up were 8.6 (range, 0.2-87.7) months and 32.7 (0.3-93.3) months, respectively. Cumulative confirmed complete hematologic response (cCHR) and major cytogenetic response (MCyR) rates were 74% (95% CI, 65-81%) and 40% (31-50%), respectively; Kaplan-Meier (K-M) probability of maintaining cCHR or MCyR at 4 years was 63% (95% CI, 50-73%) and 69% (52-81%). Cumulative incidence of on-treatment disease progression (PD)/death at 4 years was 24% (95% CI, 17-33%); K-M 4-year overall survival was 78% (68-85%). Baseline Ph+ cells ≤35 vs. ≥95% was prognostic of MCyR and CCyR by 3 and 6 months, increased baseline basophils was prognostic of PD/death, and no prior response to second-line TKI was prognostic of death. Common adverse events included diarrhea (83%), nausea (48%), vomiting (38%), and thrombocytopenia (39%). Bosutinib demonstrates durable efficacy and a toxicity profile similar to previous bosutinib studies in CP CML patients resistant/intolerant to multiple TKIs, representing an important treatment option for patients in this setting. This trial is registered at www.clinicaltrials.gov (NCT00261846). Am. J. Hematol. 91:1206-1214, 2016. © 2016 Wiley Periodicals, Inc.

Clinical outcomes of patients with advanced gastrointestinal stromal tumors: safety and efficacy in a worldwide treatment-use trial of sunitinib.

BACKGROUND: The objectives of this study were to provide sunitinib to patients with gastrointestinal stromal tumor (GIST) who were otherwise unable to obtain it and to collect broad safety and efficacy data from a large population of patients with advanced GIST after imatinib failure. (ClinicalTrials.gov identifier NCT00094029). METHODS: Imatinib-resistant/intolerant patients with advanced GIST received sunitinib on an initial dosing schedule of 50 mg daily in 6-week cycles (4 weeks on treatment, 2 weeks off treatment). Tumor assessment frequency was according to local practice, and response was assessed by investigators according to Response Evaluation Criteria in Solid Tumors version 1.0. Overall survival (OS) and safety were assessed regularly. Post hoc analyses evaluated different patterns of treatment management. RESULTS: At final data cutoff, 1124 patients comprised the intent-to-treat population, and 15% of these patients had a baseline Eastern Cooperative Oncology Group performance status ≥2. The median treatment duration was 7.0 months. The median time to tumor progression was 8.3 months (95% confidence interval [CI], 8.0-9.4 months), the median OS was 16.6 months (95% CI, 14.9-18.0 months), and 36% of patients were alive at the time of analysis. Patients for whom the initial dosing schedule was modified exhibited longer median OS (23.5 months) than those who were treated strictly according to the initial dosing schedule (11.1 months). The most common treatment-related grade 3 and 4 adverse events were hand-foot syndrome (11%), fatigue (9%), neutropenia (8%), hypertension (7%), and thrombocytopenia (6%). Treatment-related adverse events associated with cardiac function (eg, congestive heart failure and myocardial infarction) were reported at frequencies of ≤1% each. CONCLUSIONS: This treatment-use study confirms the long-term safety and efficacy of sunitinib in a large international population of patients with advanced GIST after imatinib failure.

Long-term efficacy and safety of bosutinib in patients with advanced leukemia following resistance/intolerance to imatinib and other tyrosine kinase inhibitors.

Long-term efficacy and safety of bosutinib (≥4 years follow-up from last enrolled patient) were evaluated in an ongoing phase 1/2 study in the advanced leukemia cohort with prior treatment failure (accelerated-phase [AP, n = 79] chronic myeloid leukemia [CML], blast-phase [BP, n = 64] CML, acute lymphoblastic leukemia [ALL, n = 24]). Fourteen AP, 2 BP, and 1 ALL patient remained on bosutinib at 4 years (vs. 38, 8, 1 at 1 year); median (range) treatment durations: 10.2 (0.1-88.6), 2.8 (0.03-55.9), 0.97 (0.3-89.2) months. Among AP and BP patients, 57% and 28% newly attained or maintained baseline overall hematologic response (OHR); 40% and 37% attained/maintained major cytogenetic response (MCyR) by 4 years (most by 12 months). In responders at 1 versus 4 years, Kaplan-Meier (KM) probabilities of maintaining OHR were 78% versus 49% (AP) and 28% versus 19% (BP); KM probabilities of maintaining MCyR were 65% versus 49% (AP) and 21% versus 21% (BP). Most common AEs (AP, BP) were gastrointestinal (96%; 83%), primarily diarrhea (85%; 64%), which was typically low grade (maximum grade 1/2: 81%; 59%) and transient; no patient discontinued due to diarrhea. Serious AEs occurred in 44 (56%) AP and 37 (58%) BP patients, most commonly pneumonia (n = 9) for AP and pyrexia (n = 6) for BP; 11 and 13 died within 30 days of last dose (2 considered bosutinib-related [AP] per investigator). Responses were durable in ∼50% AP responders at 4 years (∼25% BP patients responded at year 1, suggesting possible bridge-to-transplant role in BP patients); toxicity was manageable.

Characterizing fatigue associated with sunitinib and its impact on health-related quality of life in patients with metastatic renal cell carcinoma.

BACKGROUND: Using phase 3 trial data for sunitinib versus interferon (IFN)-α in treatment-naive patients with metastatic renal cell carcinoma, retrospective analyses characterized sunitinib-associated fatigue and its impact on patient-reported health-related quality of life (HRQoL). METHODS: Patients received sunitinib at a dose of 50 mg/day on a schedule of 4 weeks on/2 weeks off (375 patients) or IFN-α at a dose of 9 MU subcutaneously 3 times per week (360 patients). HRQoL was self-assessed using the Functional Assessment of Cancer Therapy-Kidney Symptom Index-15-item (FKSI-15) questionnaire, with fatigue assessed using its Disease-Related Symptoms subscale. Fatigue was also assessed by providers using Common Terminology Criteria for Adverse Events (CTCAE). A repeated-measures model (M1) and random intercept-slope model (M2) characterized sunitinib-associated fatigue over time. Another repeated-measures model examined the relationship between HRQoL scores and CTCAE fatigue grade. RESULTS: M1 demonstrated that the initial increase in patient-reported fatigue with sunitinib was worst during cycle 1, with mean values numerically better at subsequent cycles; most pairwise comparisons of consecutive CTCAE fatigue cycle means were not found to be statistically significant. M2 demonstrated that the overall trend (slope) for patient-reported and CTCAE fatigue with sunitinib was not statistically different from 0. The relationship between most HRQoL scores and CTCAE fatigue was close to linear regardless of treatment, with lower scores (worse HRQoL) corresponding to higher fatigue grade. The majority of HRQoL scores were better with sunitinib versus IFN-α for the same CTCAE fatigue grade. CONCLUSIONS: Patients reported worse fatigue during the first sunitinib cycle. However, in subsequent consecutive cycles, less fatigue was reported with no statistically significant worsening. CTCAE fatigue assessment may not fully capture patient treatment experience.

Tyrosine Kinase and Mammalian Target of Rapamycin Inhibitors in the Treatment of Advanced Renal Cell Carcinoma: Practical Clinical Implications of Pharmacologic Features.

The development of multiple vascular endothelial growth factor- and mammalian target of rapamycin-targeted therapies in advanced renal cell carcinoma has resulted in significant clinical benefit. However, the availability of multiple treatment options has led to a more complicated clinical decision-making process. Prognostic factors have been incorporated into the inclusion criteria for pivotal clinical trials and have thus provided some guidance regarding the selection and sequencing of therapy. Even within a given patient risk group and particular line of therapy, questions remain regarding the optimal choice of a targeted agent. The present review provides a practical, clinician-oriented assessment of pharmacologic factors that should be considered when a receptor tyrosine kinase or mammalian target of rapamycin kinase inhibitor is used to treat patients with advanced or metastatic renal cell carcinoma. Although these 2 classes of agents have different mechanisms of action, they are metabolized by similar pathways, resulting in broadly similar pharmacokinetic and drug-drug interaction profiles. To further individualize therapy and optimize clinical benefit, an enhanced understanding of the key pharmacologic features that differentiate these agents is important.

Heterogeneity of Patients With Intermediate-Prognosis Metastatic Renal Cell Carcinoma Treated With Sunitinib.

BACKGROUND: The Memorial Sloan Kettering Cancer Center (MSKCC) and International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) models categorize patients with 1 or 2 risk factors as intermediate prognosis (INTMP). This category encompasses 15 and 19 permutations of the MSKCC and IMDC risk factors, respectively. The purpose of the present retrospective analysis of data from INTMP patients in 6 clinical trials was to determine whether this heterogeneity influences the response to sunitinib. PATIENTS AND METHODS: Patients with INTMP metastatic renal cell carcinoma (mRCC) were identified using the MSKCC and IMDC classifications. The statistical data were analyzed using Cox regression analysis, Kaplan-Meier methods, and Pearson χ2 tests. RESULTS: The patient characteristics and risk factors were similar in the MSKCC (n = 548) and IMDC (n = 517) groups. Overall, 59% had 1 risk factor and 41% had 2 risk factors. The most common was low hemoglobin alone or with an interval of < 1 year since diagnosis. In both groups, patients with 1 risk factor had longer overall survival (OS) and progression-free survival (PFS) than did those with 2 risk factors (P < .001 for both outcomes). Patients in the IMDC group with 1 risk factor had a greater objective response rate (ORR; P = .023). In both groups, OS was longer for patients with Eastern Cooperative Oncology Group performance status (ECOG PS) 0 than for those with ECOG PS 1 or 2 (P < .001). An ECOG PS of 0 was also associated with superior PFS and ORR in the MSKCC group (P < .05). CONCLUSION: INTMP comprises a heterogeneous group of mRCC patients in whom the number of risk factors and ECOG PS might predict the outcome with sunitinib.

Effects of Bosutinib Treatment on Renal Function in Patients With Philadelphia Chromosome-Positive Leukemias.

BACKGROUND: The purpose of the study was to assess renal function in patients with Philadelphia chromosome-positive leukemias receiving bosutinib or imatinib. PATIENTS AND METHODS: Patients received first-line bosutinib (n = 248) or imatinib (n = 251; phase III trial), or second-line or later bosutinib (phase I/II trial; n = 570). Adverse events (AEs) and changes from baseline in estimated glomerular filtration rate (eGFR) and serum creatinine were assessed. RESULTS: Time from the last patient's first dose to data cutoff was ≥ 48 months. Renal AEs were reported in 73/570 patients (13%) receiving second-line or later bosutinib, and in 22/248 (9%) and 16/251 (6%) receiving first-line bosutinib and imatinib, respectively. eGFR in patients receiving bosutinib declined over time with more patients developing Grade ≥ 3b eGFR (< 45 mL/min/1.73 m2 according to the Modification of Diet in Renal Disease method) with second-line or later bosutinib (139/570, 24%) compared with first-line bosutinib (26/248, 10%) and imatinib (25/251, 10%); time to Grade ≥ 3b eGFR was shortest with second-line or later bosutinib. Similar proportions of patients receiving second-line or later bosutinib (74/139, 53%), first-line bosutinib (15/26, 58%), and first-line imatinib (15/25, 60%) improved to ≥ 45 mL/min/1.73 m2 eGFR as of the last follow-up. In a regression analysis, first-line treatment with bosutinib versus imatinib was not a significant predictor of Grade ≥ 3b eGFR. CONCLUSION: Long-term bosutinib treatment is associated with an apparently reversible decline in renal function with frequency and characteristics similar to renal decline observed with long-term imatinib treatment. Patients with risk factors for Grade ≥ 3b eGFR should be monitored closely.

The effect of information on preferences for treatments of metastatic renal cell carcinoma.

OBJECTIVE: Limited information exists regarding the effect of uncertainty in outcomes on patient preferences for metastatic renal cell carcinoma (mRCC) treatments. This study tested the effect on patients' preferences and willingness to tolerate toxicities when patients were provided with information about possible correlations between treatment-related toxicities and efficacy. RESEARCH DESIGN AND METHODS: Patients with self-reported RCC diagnosis completed an online survey. Respondents were randomly assigned to the information treatment (i.e. information about the possible correlation). Medicines were defined by progression-free survival (PFS), three toxicities potentially correlated with PFS, and one toxicity uncorrelated with PFS. Direct-elicitation questions measured willingness to tolerate the toxicities, preferences for medicines with higher toxicity but a higher chance of longer PFS, and preferences for medicines with higher toxicity during treatment and a 2 week dosing schedule break. A discrete-choice experiment (DCE) tested the effect of information on relative preferences for medication attributes. RESULTS: A total of 378 RCC patients completed the survey. Respondents who received the information reported greater willingness to accept more severe toxicities and preferred treatment with a higher chance of longer PFS but more severe toxicities. The DCE results were consistent with the hypothesis that the information increased willingness to tolerate toxicities; however, the results were only statistically significant for changes in fatigue (none to severe; p < 0.05) and hypertension (none to manageable; p < 0.05). LIMITATIONS: Online recruitment through patient support groups may limit generalizability to the population of patients with mRCC who would be candidates for the targeted therapies. CONCLUSIONS: The findings suggest that RCC patients have diverse preferences but may be willing to continue targeted therapies, even in the presence of severe toxicities, if there is a chance of improved clinical benefit. Physicians should provide patients with comprehensive information about medication features, including toxicities and efficacy (and their potential correlation), to improve compliance and optimize outcomes.