Eric Bleickardt

Dasatinib versus Imatinib in Newly Diagnosed Chronic-Phase Chronic Myeloid Leukemia

BACKGROUND Treatment with dasatinib, a highly potent BCR-ABL kinase inhibitor, has resulted in high rates of complete cytogenetic response and progression-free survival among patients with chronic myeloid leukemia (CML) in the chronic phase, after failure of imatinib treatment. We assessed the efficacy and safety of dasatinib, as compared with imatinib, for the first-line treatment of chronic-phase CML. METHODS In a multinational study, 519 patients with newly diagnosed chronic-phase CML were randomly assigned to receive dasatinib at a dose of 100 mg once daily (259 patients) or imatinib at a dose of 400 mg once daily (260 patients). The primary end point was complete cytogenetic response by 12 months, confirmed on two consecutive assessments at least 28 days apart. Secondary end points, including major molecular response, were tested at a significance level of 0.0001 to adjust for multiple comparisons. RESULTS After a minimum follow-up of 12 months, the rate of confirmed complete cytogenetic response was higher with dasatinib than with imatinib (77% vs. 66%, P=0.007), as was the rate of complete cytogenetic response observed on at least one assessment (83% vs. 72%, P=0.001). The rate of major molecular response was higher with dasatinib than with imatinib (46% vs. 28%, P<0.0001), and responses were achieved in a shorter time with dasatinib (P<0.0001). Progression to the accelerated or blastic phase of CML occurred in 5 patients who were receiving dasatinib (1.9%) and in 9 patients who were receiving imatinib (3.5%). The safety profiles of the two treatments were similar. CONCLUSIONS Dasatinib, administered once daily, as compared with imatinib, administered once daily, induced significantly higher and faster rates of complete cytogenetic response and major molecular response. Since achieving complete cytogenetic response within 12 months has been associated with better long-term, progression-free survival, dasatinib may improve the long-term outcomes among patients with newly diagnosed chronic-phase CML. (ClinicalTrials.gov number, NCT00481247.)

Elotuzumab Therapy for Relapsed or Refractory Multiple Myeloma

BACKGROUND Elotuzumab, an immunostimulatory monoclonal antibody targeting signaling lymphocytic activation molecule F7 (SLAMF7), showed activity in combination with lenalidomide and dexamethasone in a phase 1b-2 study in patients with relapsed or refractory multiple myeloma. METHODS In this phase 3 study, we randomly assigned patients to receive either elotuzumab plus lenalidomide and dexamethasone (elotuzumab group) or lenalidomide and dexamethasone alone (control group). Coprimary end points were progression-free survival and the overall response rate. Final results for the coprimary end points are reported on the basis of a planned interim analysis of progression-free survival. RESULTS Overall, 321 patients were assigned to the elotuzumab group and 325 to the control group. After a median follow-up of 24.5 months, the rate of progression-free survival at 1 year in the elotuzumab group was 68%, as compared with 57% in the control group; at 2 years, the rates were 41% and 27%, respectively. Median progression-free survival in the elotuzumab group was 19.4 months, versus 14.9 months in the control group (hazard ratio for progression or death in the elotuzumab group, 0.70; 95% confidence interval, 0.57 to 0.85; P<0.001). The overall response rate in the elotuzumab group was 79%, versus 66% in the control group (P<0.001). Common grade 3 or 4 adverse events in the two groups were lymphocytopenia, neutropenia, fatigue, and pneumonia. Infusion reactions occurred in 33 patients (10%) in the elotuzumab group and were grade 1 or 2 in 29 patients. CONCLUSIONS Patients with relapsed or refractory multiple myeloma who received a combination of elotuzumab, lenalidomide, and dexamethasone had a significant relative reduction of 30% in the risk of disease progression or death. (Funded by Bristol-Myers Squibb and AbbVie Biotherapeutics; ELOQUENT-2 ClinicalTrials.gov number, NCT01239797.).

Intermittent Target Inhibition With Dasatinib 100 mg Once Daily Preserves Efficacy and Improves Tolerability in Imatinib-Resistant and -Intolerant Chronic-Phase Chronic Myeloid Leukemia

PURPOSE Dasatinib is a BCR-ABL inhibitor, 325-fold more potent than imatinib against unmutated BCR-ABL in vitro. Phase II studies have demonstrated efficacy and safety with dasatinib 70 mg twice daily in chronic-phase (CP) chronic myelogenous leukemia (CML) after imatinib treatment failure. In phase I, responses occurred with once-daily administration despite only intermittent BCR-ABL inhibition. Once-daily treatment resulted in less toxicity, suggesting that toxicity results from continuous inhibition of unintended targets. Here, a dose- and schedule-optimization study is reported. PATIENTS AND METHODS In this open-label phase III trial, 670 patients with imatinib-resistant or -intolerant CP-CML were randomly assigned 1:1:1:1 between four dasatinib treatment groups: 100 mg once daily, 50 mg twice daily, 140 mg once daily, or 70 mg twice daily. RESULTS With minimum follow-up of 6 months (median treatment duration, 8 months; range, < 1 to 15 months), marked and comparable hematologic (complete, 86% to 92%) and cytogenetic (major, 54% to 59%; complete, 41% to 45%) response rates were observed across the four groups. Time to and duration of cytogenetic response were similar, as was progression-free survival (8% to 11% of patients experienced disease progression or died). Compared with the approved 70-mg twice-daily regimen, dasatinib 100 mg once daily resulted in significantly lower rates of pleural effusion (all grades, 7% v 16%; P = .024) and grade 3 to 4 thrombocytopenia (22% v 37%; P = .004), and fewer patients required dose interruption (51% v 68%), reduction (30% v 55%), or discontinuation (16% v 23%). CONCLUSION Dasatinib 100 mg once daily retains the efficacy of 70 mg twice daily with less toxicity. Intermittent target inhibition with tyrosine kinase inhibitors may preserve efficacy and reduce adverse events.

Transient potent BCR-ABL inhibition is sufficient to commit chronic myeloid leukemia cells irreversibly to apoptosis

The BCR-ABL inhibitor dasatinib achieves clinical remissions in chronic myeloid leukemia (CML) patients using a dosing schedule that achieves potent but transient BCR-ABL inhibition. In vitro, transient potent BCR-ABL inhibition with either dasatinib or imatinib is cytotoxic to CML cell lines, as is transient potent EGFR inhibition with erlotinib in a lung cancer cell line. Cytotoxicity correlates with the magnitude as well as the duration of kinase inhibition. Moreover, cytotoxicity with transient potent target inhibition is equivalent to prolonged target inhibition and in both cases is associated with BIM activation and rescued by BCL-2 overexpression. In CML patients receiving dasatinib once daily, response correlates with the magnitude of BCR-ABL kinase inhibition, thereby demonstrating the potential clinical utility of intermittent potent kinase inhibitor therapy.

Dasatinib or high-dose imatinib for chronic-phase chronic myeloid leukemia resistant to imatinib at a dose of 400 to 600 milligrams daily: two-year follow-up of a randomized phase 2 study (START-R).

In patients with chronic‐phase chronic myeloid leukemia (CP‐CML), imatinib resistance is of increasing importance. Imatinib dose escalation was the main treatment option before dasatinib, which has 325‐fold more potent inhibition than imatinib against unmutated Bcr‐Abl in vitro. Data with a minimum of 2 years of follow‐up were available for the current study of dasatinib and high‐dose imatinib in CP‐CML resistant to imatinib at daily doses from 400 mg to 600 mg.

Randomized phase 2 study: elotuzumab plus bortezomib/dexamethasone vs bortezomib/dexamethasone for relapsed/refractory MM.

In this proof-of-concept, open-label, phase 2 study, patients with relapsed/refractory multiple myeloma (RRMM) received elotuzumab with bortezomib and dexamethasone (EBd) or bortezomib and dexamethasone (Bd) until disease progression/unacceptable toxicity. Primary endpoint was progression-free survival (PFS); secondary/exploratory endpoints included overall response rate (ORR) and overall survival (OS). Two-sided 0.30 significance level was specified (80% power, 103 events) to detect hazard ratio (HR) of 0.69. Efficacy and safety analyses were performed on all randomized patients and all treated patients, respectively. Of 152 randomized patients (77 EBd, 75 Bd), 150 were treated (75 EBd, 75 Bd). PFS was greater with EBd vs Bd (HR, 0.72; 70% confidence interval [CI], 0.59-0.88; stratified log-rank P = .09); median PFS was longer with EBd (9.7 months) vs Bd (6.9 months). In an updated analysis, EBd-treated patients homozygous for the high-affinity FcγRIIIa allele had median PFS of 22.3 months vs 9.8 months in EBd-treated patients homozygous for the low-affinity allele. ORR was 66% (EBd) vs 63% (Bd). Very good partial response or better occurred in 36% of patients (EBd) vs 27% (Bd). Early OS results, based on 40 deaths, revealed an HR of 0.61 (70% CI, 0.43-0.85). To date, 60 deaths have occurred (28 EBd, 32 Bd). No additional clinically significant adverse events occurred with EBd vs Bd. Grade 1/2 infusion reaction rate was low (5% EBd) and mitigated with premedication. In patients with RRMM, elotuzumab, an immunostimulatory antibody, appears to provide clinical benefit without added clinically significant toxicity when combined with Bd vs Bd alone. Registered to ClinicalTrials.gov as NCT01478048.

Elotuzumab in combination with lenalidomide and dexamethasone in patients with relapsed multiple myeloma: final phase 2 results from the randomised, open-label, phase 1b–2 dose-escalation study

BACKGROUND Elotuzumab, an immunostimulatory monoclonal antibody targeting signalling lymphocytic activation molecule (SLAM) family member 7 (SLAMF7), selectively kills SLAMF7-expressing myeloma cells through direct activation and engagement of the innate immune system, and thus might have clinical benefit in the treatment of myeloma. In phase 1 of this phase 1b-2 study, 82% of patients with relapsed multiple myeloma who were given elotuzumab plus lenalidomide and dexamethasone achieved an overall response. Here we report the final phase 2 results. METHODS We did this randomised, multicentre, open-label, dose-escalation study (1703) at 17 hospitals in the USA, Canada, France, and Germany. Patients aged at least 18 years with confirmed, relapsed multiple myeloma, Eastern Cooperative Oncology Group performance status 0-2, and one to three previous therapies but no previous lenalidomide were eligible for phase 2. We randomly assigned patients (1:1) to either 10 mg/kg or 20 mg/kg intravenous elotuzumab plus oral lenalidomide (25 mg) and dexamethasone (40 mg). We stratified patients on the basis of the number of previous therapies (one versus two or three), and status of previous treatment with immunomodulatory drugs (yes or no), and used permuted block randomisation with a block size of four. Treatment was given in 28-day cycles until disease progression or unacceptable toxic effects occurred (elotuzumab was given on days 1, 8, 15, and 22 for cycles 1 to 2 and days 1 and 15 for subsequent cycles; lenalidomide was given on days 1-21 and dexamethasone once per week). The primary endpoint was the proportion of patients who achieved an objective response according to International Myeloma Working Group criteria. Primary analyses were done in the intention-to-treat population, and safety was analysed in all patients who received at least one dose of study drugs. This study is registered with ClinicalTrials.gov, number NCT00742560. FINDINGS Between Jan 4, 2010, and Dec 21, 2010, we recruited and randomly assigned 73 patients to elotuzumab (36 to 10 mg/kg, 37 to 20 mg/kg). At data cutoff (Jan 16, 2014), 13 patients remained on treatment (six on 10 mg/kg, seven on 20 mg/kg). 61 (84%) patients achieved an objective response (33 [92%] with 10 mg/kg, 28 [76%] with 20 mg/kg); 31 (42%) a very good partial response (17 [47%] with 10 mg/kg, 14 [38%] with 20 mg/kg); and 20 (27%) a partial response (10 [28%] with 10 mg/kg, 10 [27%] with 20 mg/kg). The most common treatment-emergent adverse events of any grade were diarrhoea (48 [66%]), muscle spasms (45 [62%]), and fatigue (41 [56%]). 57 (78%) patients had grade 3-4 events, the most common of which were lymphopenia (15 [21%]) and neutropenia (14 [19%]). Three deaths occurred, none related to the study drugs. INTERPRETATION Elotuzumab combined with lenalidomide and dexamethasone in patients with relapsed multiple myeloma showed acceptable safety and efficacy that seems better than that previously noted with lenalidomide and dexamethasone only. Phase 3 trials are in progress. FUNDING Bristol-Myers Squibb, AbbVie Biotherapeutics.

Dasatinib Early Intervention After Cytogenetic or Hematologic Resistance to Imatinib in Patients With Chronic Myeloid Leukemia

Although many patients with chronic myeloid leukemia (CML) respond well to imatinib therapy, a significant proportion loses their initial response. Loss of response on imatinib is often because of BCR‐ABL mutations. Dasatinib is a 325‐fold more potent inhibitor of Bcr‐Abl than imatinib and has been associated with high rates of durable responses in patients with CML in chronic phase (CP) after imatinib failure.

Dasatinib-associated major molecular responses in patients with chronic myeloid leukemia in chronic phase following imatinib failure: response dynamics and predictive value.

Dasatinib is a highly potent BCR–ABL inhibitor that has shown durable efficacy in patients with chronic phase (CP) chronic myeloid leukemia (CML) after resistance, suboptimal response, or intolerance to prior imatinib. In patients with CML, BCR–ABL transcript measurement is the most sensitive method for assessing minimal residual disease. Here, molecular responses were analyzed in 1067 patients with CML-CP treated with dasatinib during phase II/III trials. After 3, 6, 12, and 24 months of follow-up, a major molecular response (MMR) was achieved by 12, 22, 35, and 40% of patients, respectively. The 24-month MMR rate was 34% in patients with resistance or suboptimal response to imatinib (n=829) and 63% in imatinib-intolerant patients (n=238). Among patients who had achieved a complete cytogenetic response (CCyR), 72% also achieved MMR. Responses with dasatinib 100 mg once daily were similar to other doses. In landmark analyses, 24-month progression-free survival was higher in patients who had achieved MMR or CCyR at 12 months than in those without MMR or CCyR at 12 months. MMR at 12 months was associated with a longer duration of CCyR. Overall, this analysis shows that dasatinib treatment results in high MMR rates in patients with CML-CP after imatinib failure.

Pharmacokinetics and Safety of Elotuzumab Combined With Lenalidomide and Dexamethasone in Patients With Multiple Myeloma and Various Levels of Renal Impairment: Results of a Phase Ib Study

Renal impairment is associated with a poor prognosis in patients with multiple myeloma (MM), and more treatment options are needed. The pharmacokinetics of elotuzumab, a humanized IgG1 monoclonal antibody, combined with lenalidomide and dexamethasone, is not significantly different between patients with MM with and without renal impairment, suggesting that elotuzumab might be administered without dose adjustment for renal function. Introduction: The present study evaluated the pharmacokinetics and safety of elotuzumab, a humanized IgG1 monoclonal antibody against signaling lymphocyte activation molecule-F7, combined with lenalidomide and dexamethasone, in patients with multiple myeloma (MM) and renal impairment. Patients and Methods: Patients with MM and normal renal function (NRF) (creatinine clearance [CrCl] ≥ 90 mL/min), severe renal impairment (SRI) (CrCl < 30 mL/min, not requiring dialysis), or end-stage renal disease (ESRD) (requiring dialysis) were enrolled in this open-label, phase Ib study. Elotuzumab (10 mg/kg), lenalidomide (5–25 mg), and dexamethasone (40 mg) were administered in 28-day cycles until disease progression or unacceptable toxicity developed. The primary endpoint was single-dose elotuzumab pharmacokinetics. Results: A total of 26 patients (median age, 63 years) were treated (NRF, n = 8; SRI, n = 9; ESRD, n = 9). The median baseline CrCl was 105 mL/min (range, 84–146 mL/min) for those with NRF and 26 mL/min (range, 15–33 mL/min) for those with SRI. Twenty-three patients (89%) had received previous therapy (median, 2 regimens; range, 1–7). Treatment was discontinued in 6 patients with NRF, 4 with SRI, and 5 with ESRD, primarily because of disease progression. The mean elotuzumab serum concentrations were comparable across groups (n = 23). No statistically significant differences were observed in the maximum observed serum concentration, area under the concentration–time curve from time 0 to the last quantifiable serum concentration, or area under the concentration–time curve from time 0 to infinity when the SRI and ESRD groups were compared with the NRF group (P >.05). All patients had > 1 adverse event (AE). Of the 8 patients with NRF, 9 with SRI, and 9 with ESRD, 7,8, and 7 experienced grade 3 to 4 AEs. The overall response rates were 75% in the NRF, 67% in the SRI, and 56% in the ESRD groups. Conclusion: The results of the present study support the use of elotuzumab for the treatment of patients with MM and renal dysfunction without dose adjustment.