Survival and progression of mature B-cell malignancies depend on signals from the B-cell antigen receptor, and Bruton tyrosine kinase (BTK) is a critical signaling kinase in this pathway. We ...evaluated ibrutinib (PCI-32765), a small-molecule irreversible inhibitor of BTK, in patients with B-cell malignancies.
Patients with relapsed or refractory B-cell lymphoma and chronic lymphocytic leukemia received escalating oral doses of ibrutinib. Two schedules were evaluated: one, 28 days on, 7 days off; and two, once-daily continuous dosing. Occupancy of BTK by ibrutinib in peripheral blood was monitored using a fluorescent affinity probe. Dose escalation proceeded until either the maximum-tolerated dose (MTD) was achieved or, in the absence of MTD, until three dose levels above full BTK occupancy by ibrutinib. Response was evaluated every two cycles.
Fifty-six patients with a variety of B-cell malignancies were treated over seven cohorts. Most adverse events were grade 1 and 2 in severity and self-limited. Dose-limiting events were not observed, even with prolonged dosing. Full occupancy of the BTK active site occurred at 2.5 mg/kg per day, and dose escalation continued to 12.5 mg/kg per day without reaching MTD. Pharmacokinetic data indicated rapid absorption and elimination, yet BTK occupancy was maintained for at least 24 hours, consistent with the irreversible mechanism. Objective response rate in 50 evaluable patients was 60%, including complete response of 16%. Median progression-free survival in all patients was 13.6 months.
Ibrutinib, a novel BTK-targeting inhibitor, is well tolerated, with substantial activity across B-cell histologies.
This randomized, noninferiority (NI), global, phase 3 study evaluated the efficacy and safety of bendamustine plus rituximab (BR) vs a standard rituximab-chemotherapy regimen (rituximab plus ...cyclophosphamide, doxorubicin, vincristine, and prednisone R-CHOP or rituximab plus cyclophosphamide, vincristine, and prednisone R-CVP) for treatment-naive patients with indolent non-Hodgkin's lymphoma or mantle cell lymphoma. Investigators preassigned the standard treatment regimen they considered most appropriate for each patient; patients were randomized to receive BR (n = 224) or standard therapy (R-CHOP/R-CVP, n = 223) for 6 cycles; 2 additional cycles were permitted at investigator discretion. Response was assessed by a blinded independent review committee. BR was noninferior to R-CHOP/R-CVP, as assessed by the primary end point of complete response rate (31% vs 25%, respectively; P = .0225 for NI 0.88 margin). The overall response rates for BR and R-CHOP/R-CVP were 97% and 91%, respectively (P = .0102). Incidences of vomiting and drug-hypersensitivity reactions were significantly higher in patients treated with BR (P < .05), and incidences of peripheral neuropathy/paresthesia and alopecia were significantly higher in patients treated with standard-therapy regimens (P < .05). These data indicate BR is noninferior to standard therapy with regard to clinical response with an acceptable safety profile. This trial was registered at www.clinicaltrials.gov as #NCT00877006.
•The complete response rate for first-line bendamustine/rituximab was statistically noninferior to R-CHOP or R-CVP in indolent NHL or MCL.•The safety profile of bendamustine/rituximab is distinct from that of R-CHOP/R-CVP.
Purpose To evaluate the impact of the addition of bortezomib to rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) on outcomes in previously untreated patients with ...non-germinal center B-cell-like (non-GCB) diffuse large B-cell lymphoma (DLBCL). Patients and Methods After real-time determination of non-GCB DLBCL using the Hans immunohistochemistry algorithm, 206 patients were randomly assigned (1:1; stratified by International Prognostic Index IPI score) to six 21-day cycles of standard R-CHOP alone or R-CHOP plus bortezomib 1.3 mg/m
intravenously on days 1 and 4 (VR-CHOP). The primary end point, progression-free survival (PFS), was evaluated in 183 patients with centrally confirmed non-GCB DLBCL who received one or more doses of study drug (91 R-CHOP, 92 VR-CHOP). Results After a median follow-up of 34 months, with 25% (R-CHOP) and 18% (VR-CHOP) of patients having had PFS events, the hazard ratio (HR) for PFS was 0.73 (90% CI, 0.43 to 1.24) with VR-CHOP ( P = .611). Two-year PFS rates were 77.6% with R-CHOP and 82.0% with VR-CHOP; they were 65.1% versus 72.4% in patients with high-intermediate/high IPI (HR, 0.67; 90% CI, 0.34 to 1.29), and 90.0% versus 88.9% (HR, 0.85; 90% CI, 0.35 to 2.10) in patients with low/low-intermediate IPI. Overall response rate with R-CHOP and VR-CHOP was 98% and 96%, respectively. The overall survival HR was 0.75 (90% CI, 0.38 to 1.45); 2-year survival rates were 88.4% and 93.0%, respectively. In the safety population (100 R-CHOP and 101 VR-CHOP patients), grade ≥ 3 adverse events included neutropenia (53% v 49%), thrombocytopenia (13% v 29%), anemia (7% v 15%), leukopenia (26% v 25%), and neuropathy (1% v 5%). Conclusion Outcomes for newly diagnosed, prospectively enrolled patients with non-GCB DLBCL were more favorable than expected with R-CHOP and were not significantly improved by adding bortezomib.
Obinutuzumab is a glycoengineered, type 2 anti-CD20 humanized antibody with single-agent activity in relapsed chronic lymphocytic leukemia (CLL). With other CD20 antibodies, a dose-response ...relationship has been shown. We therefore performed a randomized phase 2 study in symptomatic, untreated CLL patients to evaluate if an obinutuzumab dose response exists. Obinutuzumab was given at a dose of 1000 mg (100 mg IV day 1, 900 mg day 2, 1000 mg day 8 and day 15 of cycle 1; 1000 mg day 1 of cycles 2-8) or 2000 mg (100 mg IV day 1, 900 mg day 2, 1000 mg day 3, 2000 mg day 8 and day 15 of cycle 1; 2000 mg day 1 of cycles 2-8). The primary end point was overall response rate (ORR). Eighty patients were enrolled with similar demographics: median age 67 years, 41% high-risk Rai disease, and 10% del(17p)(13.1). ORR (67% vs 49%, P = .08) and complete response (CR) or CR with incomplete cytopenia response (20% vs 5%) favored 2000 mg obinutuzumab. Overall, therapy was well tolerated, and infusion events were manageable. This study demonstrates significant efficacy of obinutuzumab monotherapy, for 1000 mg as well as for 2000 mg, in untreated CLL patients with acceptable toxicity. Although exploratory, a dose-response relationship may exist, but its relevance to improving progression-free survival is uncertain and will require further follow-up. This trial was registered at www.clinicaltrials.gov as #NCT01414205.
•Obinutuzumab monotherapy demonstrates an increased ORR with 2000 mg over 1000 mg, but no difference in progression-free survival.•No meaningful difference was observed in the overall safety profile across the 2 treatment arms.
Alvocidib is a cyclin-dependent kinase 9 inhibitor leading to downregulation of the antiapoptotic BCL-2 family member, MCL-1. Alvocidib has shown clinical activity in a timed sequential regimen with ...cytarabine and mitoxantrone in relapsed/refractory and newly diagnosed acute myeloid leukemia (AML) but has not been studied in combination with traditional 7+3 induction therapy.
A multiinstitutional phase I dose-escalation study of alvocidib on days 1-3 followed by 7+3 (cytarabine 100 mg/m
/day i.v. infusion days 5-12 and daunorubicin 60 mg/m
i.v. days 5-7) was performed in newly diagnosed AML ≤65 years. Core-binding factor AML was excluded.
There was no MTD on this study; the recommended phase II dose of alvocidib was 30 mg/m
i.v. over 30 minutes followed by 60 mg/m
i.v. infusion over 4 hours. There was one dose-limiting toxicity of cytokine release syndrome. The most common grade ≥3 nonhematologic toxicities were diarrhea (44%) and tumor lysis syndrome (34%). Overall, 69% (22/32) of patients achieved complete remission (CR). In an exploratory cohort, eight of nine (89%) patients in complete remission had no measurable residual disease, as determined by a centralized flow cytometric assay. Clinical activity was seen in patients with secondary AML, AML with myelodysplastic syndrome-related changes, and a genomic signature of secondary AML (50%, 50%, and 92% CR rates, respectively).
Alvocidib can be safely administered prior to 7+3 induction with encouraging clinical activity. These findings warrant further investigation of alvocidib combinations in newly diagnosed AML. This study was registered at clinicaltrials.gov identifier NCT03298984.
Summary
Spleen tyrosine kinase (Syk) mediates B‐cell receptor signalling in normal and malignant B cells. Entospletinib is an oral, selective Syk inhibitor. Entospletinib monotherapy was evaluated in ...a multicentre, phase 2 study of patients with relapsed or refractory indolent non‐Hodgkin lymphoma or mantle cell lymphoma (MCL). Subjects received 800 mg entospletinib twice daily. Forty‐one follicular lymphoma (FL), 17 lymphoplasmacytoid lymphoma/Waldenström macroglobulinaemia (LPL/WM), 17 marginal zone lymphoma (MZL) and 39 MCL patients were evaluated. The primary endpoint was a progression‐free survival (PFS) rate (defined as not experiencing progression or death) at 16 weeks for patients with MCL and at 24 weeks for patients with FL, LPL/WM and MZL. The most common treatment‐emergent adverse events were fatigue, nausea, diarrhoea, vomiting, headache and cough. Common laboratory abnormalities were anaemia, neutropenia and thrombocytopenia; aspartate transaminase, alanine transaminase, total bilirubin and serum creatinine were all increased. PFS at 16 weeks in the MCL cohort was 63·9% 95% confidence interval (CI) 45–77·8%; PFS at 24 weeks in the FL, LPL/WM, MCL and MZL cohorts was 51·5% (95% CI 32·8–67·4%), 69·8% (95% CI 31·8–89·4%), 56·6% (95% CI 37·5–71·8%) and 46·2% (95% CI 18·5–70·2%), respectively. Entospletinib had limited single‐agent activity with manageable toxicity in these patient populations.
Summary
Ibrutinib is effective in patients with chronic lymphocytic leukaemia (CLL); however, treatment resistance remains a problem. Ublituximab is a novel, glycoengineered anti‐CD20 monoclonal ...antibody with single‐agent activity in relapsed CLL. We report the results of a phase 2 study evaluating combination therapy with ibrutinib and ublituximab in patients with relapsed or refractory CLL. Patients received ibrutinib 420 mg once daily. Ublituximab was administered on days 1, 8 and 15 of cycle 1 followed by day 1 of cycles 2–6. Response assessments were completed at cycles 3 and 6; patients then continued on ibrutinib monotherapy per standard of care. Forty‐one of 45 enrolled patients were evaluable for efficacy. Safety was consistent with prior experience for each drug, with infusion reactions the most prevalent adverse event. Combination therapy resulted in an overall response rate (ORR) of 88% at 6 months. In the 20 patients with high‐risk features (17p or 11q deletions or TP53 mutation) and evaluable for efficacy, the ORR was 95%, with three patients (15%) achieving negative minimal residual disease. Median time to response was 8 weeks. Ublituximab in combination with ibrutinib resulted in rapid and high response rates. The long‐term clinical benefit of ublituximab will be defined by an ongoing phase 3 trial (NCT 02301156).
Patients with chronic lymphocytic leukaemia and high-risk features have poorer outcomes on ibrutinib than those without high-risk features. The aim of this study was to assess the benefit of adding ...ublituximab, an anti-CD20 monoclonal antibody, to ibrutinib therapy in this population.
We did a randomised, phase 3, multicentre study (GENUINE) of patients aged 18 years or older with relapsed or refractory chronic lymphocytic leukaemia with at least one of 17p deletion, 11q deletion, or TP53 mutation, at 119 clinics in the USA and Israel. Eligible patients had received at least one previous chronic lymphocytic leukaemia therapy and had an Eastern Cooperative Oncology Group performance status of 2 or lower. We randomised patients (1:1) using permuted block randomisation with a block size of four and stratified by previous lines of therapy (one vs two or more) to receive ibrutinib alone or ibrutinib in combination with ublituximab. Treatment allocation was not masked to patients or investigators. Ibrutinib was given orally daily at 420 mg for all cycles. Ublituximab was given intravenously in 28-day cycles, with increasing doses during cycle 1 (≤150 mg on day 1, 750 mg on day 2, and 900 mg on days 8 and 15) and continuing at 900 mg on day 1 of cycles 2-6. After cycle 6, ublituximab was given at 900 mg every three cycles. The study was initially designed with co-primary endpoints of progression-free survival and overall response rate but due to protracted patient accrual, the protocol was amended to have a single primary endpoint of independent review committee-assessed overall response rate (defined as the proportion of patients who had a partial response, complete response, or complete response with incomplete marrow recovery according to the 2008 International Workshop on CLL criteria) in the intention-to-treat population. Safety was evaluated in the population of patients who received at least one dose of study treatment. This trial is registered with ClinicalTrials.gov, NCT02301156, and the final analysis is presented.
224 patients were assessed for eligibility, of whom 126 patients were enrolled and randomly assigned to receive ublituximab plus ibrutinib (n=64) or ibrutinib alone (n=62) between Feb 6, 2015, and Dec 19, 2016. After a median follow-up of 41·6 months (IQR 36·7-47·3), the overall response rate was 53 (83%) of 64 patients in the ublituximab plus ibrutinib group and 40 (65%) of 62 patients in the ibrutinib group (p=0·020). 117 patients, including 59 in the ublituximab plus ibrutinib group and 58 in the ibrutinib group, received at least one dose of treatment and were included in safety analyses. Most adverse events were grade 1 or 2. The most common grade 3 and 4 adverse events were neutropenia (11 19% patients in the ublituximab plus ibrutinib group and seven 12% in the ibrutinib group), anaemia (five 8% and five 9%), and diarrhoea (six 10% and three 5%). The most common serious adverse events were pneumonia (six 10% in the ublituximab plus ibrutinib group and four 7% in the ibrutinib group), atrial fibrillation (four 7% and one 2%), sepsis (four 7% and one 2%), and febrile neutropenia (three 5% and one 2%). Two patients in the ublituximab plus ibrutinib group died due to adverse events (one cardiac arrest and one failure to thrive), neither of which were treatment-related. Five patients in the ibrutinib group died due to adverse events, including one cardiac arrest, one cerebral infarction, one intracranial haemorrhage, one Pneumocystis jirovecii pneumonia infection, and one unexplained death; the death due to cardiac arrest was considered to be treatment-related.
The addition of ublituximab to ibrutinib resulted in a statistically higher overall response rate without affecting the safety profile of ibrutinib monotherapy in patients with relapsed or refractory high-risk chronic lymphocytic leukaemia. These findings provide support for the addition of ublituximab to Bruton tyrosine kinase inhibitors for the treatment of these patients.
TG Therapeutics.
Protein tyrosine kinases and cancer Kolibaba, Kathryn S; Druker, Brian J
Biochimica et biophysica acta,
12/1997, Letnik:
1333, Številka:
3
Journal Article
The BRIGHT study ( ClinicalTrials.gov identifier: NCT00877006) was initiated to compare the efficacy and safety of bendamustine plus rituximab (BR) with either rituximab plus cyclophosphamide, ...doxorubicin, vincristine, and prednisone (R-CHOP) or rituximab plus cyclophosphamide, vincristine, and prednisone (R-CVP) for treatment-naive patients with indolent non-Hodgkin lymphoma or mantle-cell lymphoma. This publication provides long-term follow-up data.
Patients were monitored for a minimum of 5 years after completion of study treatment for the time-to-event end points of progression-free survival (PFS), event-free survival, duration of response, and overall survival per investigator assessment. Data on the number of patients who received second-line anticancer treatment and the occurrence of other malignancies were also collected.
The medians were not reached for any of the time-to event end points for either the BR or R-CHOP/R-CVP study treatment groups by study completion. PFS rates at 5 years were 65.5% in the BR treatment group and 55.8% in the R-CHOP/R-CVP group. The difference in PFS was considered significant with a hazard ratio of 0.61 (95% CI, 0.45 to 0.85;
= .0025). The hazard ratio for event-free survival and duration of response (
= .0020 and .0134, respectively) also favored the BR regimen over R-CHOP/R-CVP. However, no significant difference in overall survival was observed. The overall safety profiles of BR, R-CHOP, and R-CVP were as expected; no new safety data were collected during long-term follow-up. A higher number of secondary malignancies was noted in the BR treatment group.
Overall, BR demonstrated better long-term disease control than R-CHOP/R-CVP and should be considered as a first-line treatment option for patients with indolent and mantle-cell lymphoma.
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