A phase 3b study of venetoclax and azacitidine or decitabine in an outpatient setting in patients with acute myeloid leukemia.

Venetoclax, a highly selective BCL-2 inhibitor, combined with hypomethylating agents (HMAs) azacitidine or decitabine, is approved for the treatment of newly diagnosed acute myeloid leukemia (ND AML) in patients who are ineligible to receive intensive chemotherapy. Previous clinical studies initiated venetoclax plus HMA in an inpatient setting owing to concerns of tumor lysis syndrome (TLS). This study (NCT03941964) evaluated the efficacy and safety of venetoclax plus HMA in a United States community-based outpatient setting in patients with ND AML (N = 60) who were treatment naïve for AML, ineligible to receive intensive chemotherapy, had no evidence of spontaneous TLS at screening, and were deemed as appropriate candidates for outpatient initiation of venetoclax plus HMA by the investigator. Patients received venetoclax in combination with azacitidine (75 mg/m2) or decitabine (20 mg/m2) for up to 6 cycles during the study. With a median time on study of 18.3 weeks, the best response rate of composite complete remission was 66.7%, and the overall post-baseline red blood cell (RBC) and platelet transfusion independence rate was 55.0%, consistent with results of studies in which treatment was initiated in an inpatient setting. Key adverse events included nausea, anemia, thrombocytopenia, neutropenia, and white blood cell count decrease of any grade (≥50% of patients). The observed safety profile was generally consistent with that of venetoclax plus HMA observed in inpatient AML studies. With close monitoring, 2 cases of TLS were identified, appropriately managed, and the patients were able to continue study treatment. CLINICAL TRIALS REGISTRATION: This study is registered at ClinicalTrials.gov. The registration identification number is NCT03941964.

Long-term follow-up of VIALE-A: Venetoclax and azacitidine in chemotherapy-ineligible untreated acute myeloid leukemia.

Venetoclax-azacitidine is approved for treatment of patients with newly diagnosed acute myeloid leukemia (AML) ineligible for intensive chemotherapy based on the interim overall survival (OS) analysis of the VIALE-A study (NCT02993523). Here, long-term follow-up is presented to address survival benefit and long-term outcomes with venetoclax-azacitidine. Patients with newly diagnosed AML who were ineligible for intensive chemotherapy were randomized 2:1 to receive venetoclax-azacitidine or placebo-azacitidine. OS was the primary endpoint; complete remission with/without blood count recovery (CR/CRi) was a key secondary endpoint. This final analysis was conducted when 100% of the predefined 360 OS events occurred. In VIALE-A, 431 patients were enrolled to venetoclax-azacitidine (n = 286) or placebo-azacitidine (n = 145). At 43.2 months median follow-up, median OS was 14.7 months (95% confidence interval [CI], 12.1-18.7) with venetoclax-azacitidine, and 9.6 months (95% CI, 7.4-12.7) with placebo-azacitidine (hazard ratio, 0.58 [95% CI, 0.47-0.72], p < .001); the estimated 24-month OS rate was 37.5% and 16.9%, respectively. Median OS for patients with IDH1/2 mutations and those with measurable residual disease responses was reached in this final analysis. CR/CRi rate was similar to interim analysis. Any-grade hematologic and gastrointestinal adverse events were most common in venetoclax-azacitidine and placebo-azacitidine arms, including thrombocytopenia (47% and 42%) and neutropenia (43% and 29%). No new safety signals were identified. Long-term efficacy and safety confirm venetoclax-azacitidine is an improvement in standard-of-care for patients with AML who are not eligible for intensive chemotherapy because of advanced age or comorbidities.

Azacitidine and Venetoclax in Previously Untreated Acute Myeloid Leukemia.

BACKGROUND: Older patients with acute myeloid leukemia (AML) have a dismal prognosis, even after treatment with a hypomethylating agent. Azacitidine added to venetoclax had promising efficacy in a previous phase 1b study. METHODS: We randomly assigned previously untreated patients with confirmed AML who were ineligible for standard induction therapy because of coexisting conditions, because they were 75 years of age or older, or both to azacitidine plus either venetoclax or placebo. All patients received a standard dose of azacitidine (75 mg per square meter of body-surface area subcutaneously or intravenously on days 1 through 7 every 28-day cycle); venetoclax (target dose, 400 mg) or matching placebo was administered orally, once daily, in 28-day cycles. The primary end point was overall survival. RESULTS: The intention-to-treat population included 431 patients (286 in the azacitidine-venetoclax group and 145 in the azacitidine-placebo [control] group). The median age was 76 years in both groups (range, 49 to 91). At a median follow-up of 20.5 months, the median overall survival was 14.7 months in the azacitidine-venetoclax group and 9.6 months in the control group (hazard ratio for death, 0.66; 95% confidence interval, 0.52 to 0.85; P<0.001). The incidence of complete remission was higher with azacitidine-venetoclax than with the control regimen (36.7% vs. 17.9%; P<0.001), as was the composite complete remission (complete remission or complete remission with incomplete hematologic recovery) (66.4% vs. 28.3%; P<0.001). Key adverse events included nausea of any grade (in 44% of the patients in the azacitidine-venetoclax group and 35% of those in the control group) and grade 3 or higher thrombocytopenia (in 45% and 38%, respectively), neutropenia (in 42% and 28%), and febrile neutropenia (in 42% and 19%). Infections of any grade occurred in 85% of the patients in the azacitidine-venetoclax group and 67% of those in the control group, and serious adverse events occurred in 83% and 73%, respectively. CONCLUSIONS: In previously untreated patients who were ineligible for intensive chemotherapy, overall survival was longer and the incidence of remission was higher among patients who received azacitidine plus venetoclax than among those who received azacitidine alone. The incidence of febrile neutropenia was higher in the venetoclax-azacitidine group than in the control group. (Funded by AbbVie and Genentech; VIALE-A ClinicalTrials.gov number, NCT02993523.).

A phase 1b study of venetoclax and azacitidine combination in patients with relapsed or refractory myelodysplastic syndromes.

Patients with relapsed/refractory (R/R) higher-risk myelodysplastic syndromes (MDS) have a dismal median overall survival (OS) after failing hypomethylating agent (HMA) treatment. There is no standard of care for patients after HMA therapy failure; hence, there is a critical need for effective therapeutic strategies. Herein, we present the safety and efficacy of venetoclax + azacitidine in patients with R/R MDS. This phase 1b, open-label, multicenter study enrolled patients ≥18 years. Patients were treated with escalating doses of oral venetoclax: 100, 200, or 400 mg daily for 14 days every 28-day cycle. Azacitidine was administered on Days 1-7 every cycle at 75 mg/m2 /day intravenously/subcutaneously. Responses were assessed per modified 2006 International Working Group (IWG) criteria. Forty-four patients (male 86%, median age 74 years) received venetoclax + azacitidine treatment. Median follow-up was 21.2 months. Hematological adverse events of Grade ≥ 3 included febrile neutropenia (34%), thrombocytopenia (32%), neutropenia (27%), and anemia (18%). Pneumonia (23%) was the most common Grade ≥ 3 infection. Marrow responses were seen including complete remission (CR, n = 3, 7%) and marrow CR (mCR, n = 14, 32%); 36% (16/44) achieved transfusion independence (TI) for RBCs and/or platelets, and 43% (6/14) with mCR achieved hematological improvement (HI). The median time to CR/mCR was 1.2 months, and the median duration of response for CR + mCR was 8.6 months. Median OS was 12.6 months. Venetoclax + azacitidine shows activity in patients with R/R MDS following prior HMA therapy failure and provides clinically meaningful benefits, including HI and TI, and encouraging OS.

Venetoclax exposure-efficacy and exposure-safety relationships in patients with treatment-naïve acute myeloid leukemia who are ineligible for intensive chemotherapy.

This study evaluated venetoclax population pharmacokinetics (popPK) in patients with treatment-naïve acute myeloid leukemia and assessed the relationship between venetoclax exposure and clinical response for venetoclax in combination with either a hypomethylating agent (HMA) or low-dose cytarabine (LDAC). A total of 771 patients who received venetoclax from 5 Phase 1-3 studies were included in the popPK model. Exposure-response analyses included data from 575 patients for venetoclax/placebo plus HMA and 279 patients for venetoclax/placebo plus LDAC. The popPK model successfully characterized venetoclax plasma concentrations over time and confirmed venetoclax exposure did not vary significantly with age, weight, sex, mild to moderate hepatic impairment, or mild to severe renal impairment. Asian patients had 67% higher mean relative bioavailability than non-Asian patients, however the range of exposures in Asian patients was similar to non-Asian patients. For all efficacy endpoints with both treatment combinations, efficacy was higher in the venetoclax treatment groups compared with the respective control arm of placebo plus azacitidine or LDAC. Within patients who received venetoclax, no significant exposure-efficacy relationships were identified for either treatment combination, indicating that the beneficial effects of venetoclax were already maximized in the dose ranges studied. There was no apparent effect of venetoclax exposure on treatment-emergent Grade ≥3 thrombocytopenia or infections for either combination. Rates of treatment-emergent Grade ≥3 neutropenia were higher in the venetoclax treatment arms compared with the respective control arms; however, within patients who received venetoclax, there was only a shallow relationship or no apparent relationship with venetoclax exposure for venetoclax plus HMA or LDAC, respectively. Along with the efficacy and safety data previously published, the exposure-response analyses support the venetoclax dose regimens of 400 mg once daily (QD) plus HMA and 600 mg QD plus LDAC in treatment-naïve AML patients who are ineligible for intensive chemotherapy.

Venetoclax plus azacitidine in Japanese patients with untreated acute myeloid leukemia ineligible for intensive chemotherapy.

BACKGROUND: The phase 3 VIALE-A trial (NCT02993523) reported that venetoclax-azacitidine significantly prolonged overall survival compared with placebo-azacitidine in patients with newly diagnosed acute myeloid leukemia ineligible for intensive chemotherapy. Herein, efficacy and safety of venetoclax-azacitidine are analyzed in the Japanese subgroup of VIALE-A patients. METHODS: Eligible Japanese patients were randomized 2:1 to venetoclax-azacitidine (N = 24) or placebo-azacitidine (N = 13). Primary endpoints for Japan were overall survival and complete response (CR) + CR with incomplete hematologic recovery (CRi). Venetoclax (target dose 400 mg) was given orally once daily. Azacitidine (75 mg/m2) was administered subcutaneously or intravenously on Days 1-7 of each 28-day cycle. RESULTS: Median follow-up was 16.3 months (range, 1.0-20.3). Median overall survival was not reached with venetoclax-azacitidine (hazard ratio 0.409 and 95% confidence interval: 0.151, 1.109); overall survival estimate was higher with venetoclax-azacitidine than placebo-azacitidine at 12 (67 and 46%) and 18 months (57 and 31%), respectively. CR and CRi rates were 67% with venetoclax-azacitidine and 15% with placebo-azacitidine. Most common any-grade adverse events were febrile neutropenia (79 and 39%), thrombocytopenia (54 and 77%), constipation (54 and 54%) and decreased appetite (54 and 38%) in the venetoclax-azacitidine and placebo-azacitidine arms, respectively. Only 1 patient in the venetoclax-azacitidine arm, and no patients in the placebo-azacitidine arm, had grade 4 febrile neutropenia that led to treatment discontinuation. CONCLUSIONS: This Japanese subgroup analysis of VIALE-A demonstrates comparable safety and efficacy outcomes compared with the global study and supports venetoclax-azacitidine as first-line standard-of-care for Japanese treatment-naive patients with acute myeloid leukemia who are ineligible for intensive chemotherapy.

Venetoclax combined with decitabine or azacitidine in treatment-naive, elderly patients with acute myeloid leukemia.

Older patients with acute myeloid leukemia (AML) respond poorly to standard induction therapy. B-cell lymphoma 2 (BCL-2) overexpression is implicated in survival of AML cells and treatment resistance. We report safety and efficacy of venetoclax with decitabine or azacitidine from a large, multicenter, phase 1b dose-escalation and expansion study. Patients (N = 145) were at least 65 years old with treatment-naive AML and were ineligible for intensive chemotherapy. During dose escalation, oral venetoclax was administered at 400, 800, or 1200 mg daily in combination with either decitabine (20 mg/m2, days 1-5, intravenously [IV]) or azacitidine (75 mg/m2, days 1-7, IV or subcutaneously). In the expansion, 400 or 800 mg venetoclax with either hypomethylating agent (HMA) was given. Median age was 74 years, with poor-risk cytogenetics in 49% of patients. Common adverse events (>30%) included nausea, diarrhea, constipation, febrile neutropenia, fatigue, hypokalemia, decreased appetite, and decreased white blood cell count. No tumor lysis syndrome was observed. With a median time on study of 8.9 months, 67% of patients (all doses) achieved complete remission (CR) + CR with incomplete count recovery (CRi), with a CR + CRi rate of 73% in the venetoclax 400 mg + HMA cohort. Patients with poor-risk cytogenetics and those at least 75 years old had CR + CRi rates of 60% and 65%, respectively. The median duration of CR + CRi (all patients) was 11.3 months, and median overall survival (mOS) was 17.5 months; mOS has not been reached for the 400-mg venetoclax cohort. The novel combination of venetoclax with decitabine or azacitidine was effective and well tolerated in elderly patients with AML (This trial was registered at www.clinicaltrials.gov as #NCT02203773).

Efficacy of venetoclax in relapsed chronic lymphocytic leukemia is influenced by disease and response variables.

To define the efficacy of venetoclax with extended follow-up and identify clinical or biological treatment effect modifiers, updated data for previously treated patients with chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) enrolled in 4 early-phase trials were pooled. Rates of response, complete remission (CR/CRi), and undetectable minimal residual disease (U-MRD) were analyzed for all patients (n = 436) and for those patients who were planned to receive 400 mg/day monotherapy (n = 347). Univariate and multiple regression analyses were performed to identify the pretreatment factors associated with response rates and duration of response (DoR). Objective responses were documented in 75% of all patients, including 22% CR/CRi. Overall, 27% and 16% of the patients achieved U-MRD in blood and marrow, respectively. Estimated median progression-free survival (PFS), DoR, and time to progression were 30.2, 38.4, and 36.9 months, respectively. Similar efficacy outcomes were observed within the 400 mg/day monotherapy subset. For those who achieved CR/CRi, the 3-year PFS estimate was 83%. DoR was superior for patients achieving CR/CRi or U-MRD in landmark analyses. In multiple regression analyses, bulky lymphadenopathy (≥5 cm) and refractoriness to B-cell receptor inhibitor (BCRi) therapy were significantly associated with lower CR rate and shorter DoR. Fewer prior therapies were associated with higher CR rate, but not DoR. Chromosome 17p deletion and/or TP53 mutation and NOTCH1 mutation were consistently associated with shorter DoR, but not probability of response. Thus, both pretreatment factors and depth of response correlated with DoR with venetoclax. Patients without bulky lymphadenopathy, BCRi-refractory CLL, or an adverse mutation profile had the most durable benefit.

Venetoclax with azacitidine or decitabine in patients with newly diagnosed acute myeloid leukemia: Long term follow-up from a phase 1b study.

This analysis represents the longest-term follow-up for patients with acute myeloid leukemia (AML) treated with 400 mg of venetoclax plus azacitidine or decitabine. Adults with newly diagnosed AML ineligible for intensive chemotherapy were enrolled in an open-label, non-randomized, multicenter phase 1b trial of venetoclax with azacitidine (AZA; 75 mg/m2 ; days 1-7) or decitabine (DEC; 20 mg/m2 ; days 1-5). Endpoints included safety, response rates (complete remission [CR], CR with incomplete blood count recovery [CRi]), response duration and overall survival (OS). The median follow-up time was 29 and 40 months for patients treated with venetoclax plus AZA and DEC combinations, respectively. Key Grade ≥ 3 AEs (AZA and DEC) were febrile neutropenia (39% and 65%), anemia (30% and 26%), thrombocytopenia (25% and 23%), and neutropenia (20% and 10%). The CR/CRi rate was 71% for venetoclax plus AZA and 74% for venetoclax plus DEC. The median duration of CR/CRi was 21.9 months and 15.0 months, and the median OS was 16.4 months and 16.2 months, for venetoclax plus AZA and DEC, respectively. These results support venetoclax plus hypomethylating agents as highly effective frontline AML therapies for patients unfit for intensive chemotherapy.

Venetoclax in combination with azacitidine in Japanese patients with acute myeloid leukaemia: phase 1 trial findings.

BACKGROUND: Venetoclax plus azacitidine is indicated in the USA for the treatment of newly diagnosed acute myeloid leukaemia in older patients (≥75 years) or those ineligible for induction chemotherapy due to co-morbidities. METHODS: In this phase 1/2 study (NCT02265731), Japanese patients (≥60 years) with untreated (ineligible for induction chemotherapy) or relapsed/refractory acute myeloid leukaemia received oral venetoclax 400 mg/day (3-day ramp up in cycle 1) plus subcutaneous or intravenous azacitidine 75 mg/m2 on days 1-7 per 28-day cycle until disease progression or unacceptable toxicity. RESULTS: As of 10 December 2019, six patients were enrolled (median age: 75 years; untreated: n = 5; relapsed/refractory: n = 1); median treatment duration: 10.3 months (range, 0.7-29.4). Most common grade ≥ 3 adverse events were lymphopaenia and febrile neutropaenia (n = 4 each). Four patients reported serious adverse events; only an event of grade 3 fungal pneumonia was considered possibly related to both study drugs, requiring dose interruption of venetoclax and delay of azacitidine. Five (83%) patients had responses (complete remission: n = 3). Median time to first response of complete remission/complete remission with incomplete count recovery was 1.0 month (range, 0.8-5.5); median overall survival: 15.7 months (95% confidence interval: 6.2, not reached). CONCLUSIONS: Venetoclax plus azacitidine was well tolerated and showed high response rates in Japanese patients with acute myeloid leukaemia.

Venetoclax for patients with chronic lymphocytic leukemia who progressed during or after idelalisib therapy.

B-cell receptor pathway inhibitors (BCRis) have transformed treatment of chronic lymphocytic leukemia (CLL); however, the efficacy of therapies for patients whose disease is refractory to/relapses after (R/R) BCRis is unknown. Venetoclax is a selective, orally bioavailable BCL-2 inhibitor with activity in patients with CLL, including those who are heavily pretreated or have 17p deletion. This phase 2 study prospectively evaluated venetoclax in patients with R/R CLL after ibrutinib or idelalisib; here we report on patients who received idelalisib as the last BCRi before enrollment. Venetoclax was initiated at 20 mg daily, followed by intrapatient ramp-up to 400 mg daily. Primary objectives included efficacy (objective response rate [ORR]) and safety of venetoclax. The study enrolled 36 patients who previously received idelalisib (ORR, 67% [24/36]); 2 patients achieved complete remission, and 1 had complete remission with incomplete bone marrow recovery. Median progression-free survival (PFS) has not yet been reached; estimated 12-month PFS was 79%. The most common adverse events (AEs; all grades) were neutropenia (56%), diarrhea (42%), upper respiratory tract infection (39%), thrombocytopenia (36%), nausea (31%), fatigue (28%), cough (22%), rash (22%), and anemia (22%). Grade 3 or 4 AEs were primarily hematologic (neutropenia [50%], thrombocytopenia [25%], and anemia [17%]). No patients experienced tumor lysis syndrome. Venetoclax demonstrated promising clinical activity and favorable tolerability in patients with CLL whose disease progressed during or after idelalisib therapy. This trial was registered at www.clinicaltrials.gov as #NCT02141282.

Utility of positron emission tomography-computed tomography in patients with chronic lymphocytic leukemia following B-cell receptor pathway inhibitor therapy.

The utility of positron emission tomography-computed tomography (PET-CT) in distinguishing Richter's transformation versus chronic lymphocytic leukemia (CLL) progression after ibrutinib and/or idelalisib was assessed in a post hoc analysis of a phase II study of venetoclax. Patients underwent PET-CT at screening and were not enrolled/treated if Richter's transformation was confirmed pathologically. Of 167 patients screened, 57 met criteria for biopsy after PET-CT. Of 35 patients who underwent biopsy, eight had Richter's transformation, two had another malignancy, and 25 had CLL. A PET-CT maximum standardized uptake value (SUVmax) ≥10 had 71% sensitivity and 50% specificity for detecting Richter's transformation [Odds Ratio (OR): 2.5, 95%CI: 0.4-15; P=0.318]. Response rate to venetoclax was similar for screening SUVmax <10 versus ≥10 (65% vs. 62%) (n=127 enrolled), though median progression-free survival was longer at <10 months (24.7 vs. 15.4 months; P=0.0335). Six patients developed Richter's transformation on venetoclax, of whom two had screening biopsy demonstrating CLL (others did not have a biopsy) and five had screening SUVmax <10. We have defined the test characteristics for PET-CT to distinguish progression of CLL as compared to Richter's transformation when biopsied in patients treated with B-cell receptor signaling pathway inhibitors. Overall diminished sensitivity and specificity as compared to prior reports of patients treated with chemotherapy/chemoimmunotherapy suggest it has diminished ability to discriminate these two diagnoses using a SUVmax ≥10 cutoff. This cutoff did not identify venetoclax-treated patients with an inferior response but may be predictive of inferior progression-free survival. (Registered at clinicaltrials.gov identifier: 02141282).

Optimizing venetoclax dose in combination with low intensive therapies in elderly patients with newly diagnosed acute myeloid leukemia: An exposure-response analysis.

The objective of this research was to characterize the venetoclax exposure-efficacy and exposure-safety relationships and determine its optimal dose in elderly patients with newly diagnosed acute myeloid leukemia (AML) receiving venetoclax in combination with low intensity therapies (hypomethylating agent [HMA; azacitidine or decitabine] or low-dose cytarabine [LDAC]). A total of 212 patients from the HMA study and 92 patients from the LDAC study were included in the exposure-safety analyses. Those who received at least one dose of venetoclax and had at least one measurable response (201 and 83 in the HMA and LDAC studies, respectively) were included in the exposure-efficacy analyses. The probability of response based on International Working Group (IWG) for AML response criteria, adverse events of grade 3 or worse neutropenia or infection or a serious adverse event was modeled using logistic regression analyses to characterize the venetoclax exposure-response relationships. In combination with an HMA, increasing concentrations of venetoclax, up to those associated with a less than or equal to 400-mg once daily (QD) dose, were associated with a higher probability of response, with a trend for flat or decreasing probabilities of response thereafter. In combination with LDAC, increasing concentrations of venetoclax were associated with higher probabilities of response, with no plateau observed. Increasing concentrations of venetoclax were not associated with increasing probability of any safety event except for a slight increase in grade 3 or worse infections with HMAs; however, tolerability issues were observed at doses of greater than or equal to 800 mg QD in each study. Exposure-response analyses support the use of venetoclax 400 mg QD in combination with an HMA and 600 mg QD in combination with LDAC (ie, the next highest dose evaluated below 800 mg in each combination) to safely maximize the probability of response in elderly patients with newly diagnosed AML.

Safety and preliminary efficacy of venetoclax with decitabine or azacitidine in elderly patients with previously untreated acute myeloid leukaemia: a non-randomised, open-label, phase 1b study.

BACKGROUND: Elderly patients (aged ≥65 years) with acute myeloid leukaemia have poor outcomes and no effective standard-of-care therapy exists. Treatment with hypomethylating agents such as azacitidine and decitabine is common, but responses are modest and typically short-lived. The oral anti-apoptotic B-cell lymphoma 2 protein inhibitor, venetoclax, has shown promising single-agent activity in patients with relapsed or refractory acute myeloid leukaemia and preclinical data suggested synergy between hypomethylating agents and venetoclax, which led to this combination phase 1b study. METHODS: Previously untreated patients aged 65 years and over with acute myeloid leukaemia who were ineligible for standard induction therapy were enrolled into this non-randomised, open-label, phase 1b study. Patients were required to have an Eastern Cooperative Oncology Group performance status of 0-2 and either intermediate-risk or poor-risk cytogenetics. Patients were enrolled into one of three groups for the dose-escalation phase of this study: group A (venetoclax and intravenous decitabine 20 mg/m2 [days 1-5 of each 28-day cycle]), group B (venetoclax and subcutaneous or intravenous azacitidine 75 mg/m2 [days 1-7 of each 28-day cycle]), and group C (a venetoclax and decitabine substudy with the oral CYP3A inhibitor posaconazole, 300 mg twice on cycle 1, day 21, and 300 mg once daily from cycle 1, days 22-28, to assess its effect on venetoclax pharmacokinetics). Dose escalation followed a standard 3 + 3 design with at least three evaluable patients enrolled per cohort; daily target doses of venetoclax for groups A and B were 400 mg (cohort 1), 800 mg (cohorts 2 and 3), and 1200 mg (cohort 4), and 400 mg for group C. The primary endpoints were the safety and pharmacokinetics of venetoclax plus decitabine or azacitidine, and to determine the maximum tolerated dose and recommended phase 2 dose. Secondary endpoints included the preliminary anti-leukaemic activity of venetoclax with decitabine or azacitidine through the analysis of overall response, duration of response, and overall survival. We analysed safety, pharmacokinetics, and anti-leukaemic activity in all patients who received one or more venetoclax doses. The expansion phase of the study is ongoing but is closed to accrual. This trial is registered with ClinicalTrials.gov, number NCT02203773. FINDINGS: 57 patients were enrolled in the study. 23 patients in group A and 22 patients in group B were enrolled between Nov 19, 2014, and Dec 15, 2015, and 12 patients in group C were enrolled between June 14, 2015, and Jan 16, 2016. As of data cutoff on June 15, 2016, the most common grade 3-4 treatment-emergent adverse events were thrombocytopenia (27 [47%] of 57 patients; nine in group A, 13 in group B, and five in group C), febrile neutropenia (24 [42%] of 57; 11 in group A, ten in group B, and three in group C), and neutropenia (23 [40%] of 57; 12 in group A, eight in group B, and three in group C). The most common serious treatment-emergent adverse event in groups A and B was febrile neutropenia (seven [30%] of 23 patients vs seven [32%] of 22), whereas in group C it was lung infection (four [33%] of 12 patients). 49 (86%) of 57 patients had treatment-related adverse events; the most common in groups A and B included nausea (12 [52%] patients vs seven [32%] patients), fatigue (six [26%] patients vs seven [32%]), and decreased neutrophil count (six [26%] patients vs six [27%]), whereas in group C the most common were nausea (seven [58%] of 12 patients), leucopenia (six [50%]), vomiting (five [42%]), and decreased platelet count (five [42%]). The maximum tolerated dose was not reached. The recommended phase 2 dose was 400 mg once a day or 800 mg with an interrupted dosing schedule (safety expansion). In total, four (7%) of 57 patients had died within 30 days of the first venetoclax dose caused by sepsis (group B), bacteraemia (group A), lung infection (group C), and respiratory failure (group A). Tumour lysis syndrome was not observed. Decitabine and azacitidine did not substantially affect venetoclax exposures. Overall, 35 (61%; 95% CI 47·6-74·0) of 57 patients achieved complete remission or complete remission with incomplete marrow recovery. In groups A and B, 27 (60%; 95% CI 44·3-74·3) of 45 patients had complete remission or complete remission with incomplete marrow recovery. INTERPRETATION: Venetoclax plus hypomethylating agent therapy seems to be a novel, well-tolerated regimen with promising activity in this underserved patient population. Evaluation of expansion cohorts is ongoing at 400 mg and 800 mg doses using both hypomethylating agent combinations. FUNDING: AbbVie and Genentech.

Venetoclax for chronic lymphocytic leukaemia progressing after ibrutinib: an interim analysis of a multicentre, open-label, phase 2 trial.

BACKGROUND: Therapy targeting Bruton's tyrosine kinase (BTK) with ibrutinib has transformed the treatment of chronic lymphocytic leukaemia. However, patients who are refractory to or relapse after ibrutinib therapy have poor outcomes. Venetoclax is a selective, orally bioavailable inhibitor of BCL-2 active in previously treated patients with relapsed or refractory chronic lymphocytic leukaemia. In this study, we assessed the activity and safety of venetoclax in patients with chronic lymphocytic leukaemia who are refractory to or relapse during or after ibrutinib therapy. METHODS: In this interim analysis of a multicentre, open-label, non-randomised, phase 2 trial, we enrolled patients aged 18 years or older with a documented diagnosis of chronic lymphocytic leukaemia according to the 2008 International Workshop on Chronic Lymphocytic Leukemia (IWCLL) criteria and an Eastern Cooperative Oncology Group performance score of 2 or lower. All patients had relapsed or refractory disease after previous treatment with a BCR signalling pathway inhibitor. All patients were screened for Richter's transformation and cases confirmed by biopsy were excluded. Eligible patients received oral venetoclax, starting at 20 mg per day with stepwise dose ramp-up over 5 weeks to 400 mg per day. Patients with rapidly progressing disease received an accelerated dosing schedule (to 400 mg per day by week 3). The primary endpoint was overall response, defined as the proportion of patients with an overall response per investigator's assessment according to IWCLL criteria. All patients who received at least one dose of venetoclax were included in the activity and safety analyses. This study is ongoing; data for this interim analysis were collected per regulatory agencies' request as of June 30, 2017. This trial is registered with ClinicalTrials.gov, number NCT02141282. FINDINGS: Between September, 2014, and November, 2016, 127 previously treated patients with relapsed or refractory chronic lymphocytic leukaemia were enrolled from 15 sites across the USA. 91 patients had received ibrutinib as the last BCR inhibitor therapy before enrolment, 43 of whom were enrolled in the main cohort and 48 in the expansion cohort recruited later after a protocol amendment. At the time of analysis, the median follow-up was 14 months (IQR 8-18) for all 91 patients, 19 months (9-27) for the main cohort, and 12 months (8-15) for the expansion cohort. 59 (65%, 95% CI 53-74) of 91 patients had an overall response, including 30 (70%, 54-83) of 43 patients in the main cohort and 29 (60%, 43-72) of 48 patients in the expansion cohort. The most common treatment-emergent grade 3 or 4 adverse events were neutropenia (46 [51%] of 91 patients), thrombocytopenia (26 [29%]), anaemia (26 [29%]), decreased white blood cell count (17 [19%]), and decreased lymphocyte count (14 [15%]). 17 (19%) of 91 patients died, including seven because of disease progression. No treatment-related deaths occurred. INTERPRETATION: The results of this interim analysis show that venetoclax has durable clinical activity and favourable tolerability in patients with relapsed or refractory chronic lymphocytic leukaemia whose disease progressed during or after discontinutation of ibrutinib therapy. The durability of response to venetoclax will be assessed in the final analysis in 2019. FUNDING: AbbVie, Genentech.

Tumor Lysis Syndrome in Chronic Lymphocytic Leukemia with Novel Targeted Agents.

Tumor lysis syndrome (TLS) is an uncommon but potentially life-threatening complication associated with the treatment of some cancers. If left untreated, TLS may result in acute renal failure, cardiac dysrhythmia, neurologic complications, seizures, or death. Tumor lysis syndrome is most commonly observed in patients with hematologic malignancies with a high proliferation rate undergoing treatment with very effective therapies. In chronic lymphocytic leukemia (CLL), historically, TLS has been observed less often, owing to a low proliferation rate and slow response to chemotherapy. New targeted therapies have recently been approved in the treatment of CLL, including the oral kinase inhibitors, idelalisib and ibrutinib, and the B-cell lymphoma-2 protein inhibitor, venetoclax. Several others are also under development, and combination strategies of these agents are being explored. This review examines the diagnosis, prevention, and management of TLS and summarizes the TLS experience in CLL clinical trials with newer targeted agents. Overall, the risk of TLS is small, but the consequences may be fatal; therefore, patients should be monitored carefully. Therapies capable of eliciting rapid response and combination regimens are increasingly being evaluated for treatment of CLL, which may pose a higher risk of TLS. For optimal management, patients at risk for TLS require prophylaxis and close monitoring with appropriate tests and appropriate management to correct laboratory abnormalities, which allows for safe and effective disease control. IMPLICATIONS FOR PRACTICE: Tumor lysis syndrome (TLS) is a potentially fatal condition observed with hematologic malignancies, caused by release of cellular components in the bloodstream from rapidly dying tumor cells. The frequency and severity of TLS is partly dependent upon the biology of the disease and type of therapy administered. Novel targeted agents highly effective at inducing rapid cell death in chronic lymphocytic leukemia (CLL) may pose a risk for TLS in patients with tumors characterized by rapid growth, high tumor burden, and/or high sensitivity to treatment. In this review, prevention strategies and management of patients with CLL who develop TLS are described.