Advanced systemic mastocytosis comprises rare hematologic neoplasms that are associated with a poor prognosis and lack effective treatment options. The multikinase inhibitor midostaurin inhibits KIT ...D816V, a primary driver of disease pathogenesis.
We conducted an open-label study of oral midostaurin at a dose of 100 mg twice daily in 116 patients, of whom 89 with mastocytosis-related organ damage were eligible for inclusion in the primary efficacy population; 16 had aggressive systemic mastocytosis, 57 had systemic mastocytosis with an associated hematologic neoplasm, and 16 had mast-cell leukemia. The primary outcome was the best overall response.
The overall response rate was 60% (95% confidence interval CI, 49 to 70); 45% of the patients had a major response, which was defined as complete resolution of at least one type of mastocytosis-related organ damage. Response rates were similar regardless of the subtype of advanced systemic mastocytosis, KIT mutation status, or exposure to previous therapy. The median best percentage changes in bone marrow mast-cell burden and serum tryptase level were -59% and -58%, respectively. The median overall survival was 28.7 months, and the median progression-free survival was 14.1 months. Among the 16 patients with mast-cell leukemia, the median overall survival was 9.4 months (95% CI, 7.5 to not estimated). Dose reduction owing to toxic effects occurred in 56% of the patients; re-escalation to the starting dose was feasible in 32% of those patients. The most frequent adverse events were low-grade nausea, vomiting, and diarrhea. New or worsening grade 3 or 4 neutropenia, anemia, and thrombocytopenia occurred in 24%, 41%, and 29% of the patients, respectively, mostly in those with preexisting cytopenias.
In this open-label study, midostaurin showed efficacy in patients with advanced systemic mastocytosis, including the highly fatal variant mast-cell leukemia. (Funded by Novartis Pharmaceuticals and others; ClinicalTrials.gov number, NCT00782067.).
VA-associated symptoms included chest pain, palpitations, dizziness, syncope, heart failure (HF) symptoms, and sudden cardiac death. ...subgroup analysis among patients without baseline coronary ...artery disease (CAD) and/or left ventricular ejection fraction <50% (HF with reduced ejection fraction) was performed. In a multivariable model, only previous atrial fibrillation was associated with arrhythmic events. ...among those without baseline CAD and HF with reduced ejection fraction, 6 patients had an incident VA event, corresponding to an estimated 100,000 person-year incidence rate of 596 (Figure 1).
Ibrutinib is associated with dramatic efficacy against B-cell malignancies. Yet, it has been linked with potentially limiting cardiotoxicity, including emerging reports of profound hypertension ...(HTN). The long-term incidence, severity, and impact of HTN development with ibrutinib are unknown. Therefore, in 562 consecutive patients treated with ibrutinib for B-cell malignancies from 2009 through 2016, we assessed the new/incident or worsened HTN (systolic blood pressure BP cutoff, 130 mm Hg). Observed incident HTN rates were compared with Framingham-heart–predicted incident HTN rates. We also evaluated the relationship of HTN to the development of other major adverse cardiovascular events (MACEs), including arrhythmia, myocardial infarction, stroke, heart failure, and cardiovascular death. Further, we assessed the effects of different antihypertensive classes on ibrutinib-related HTN. Overall, 78.3% of ibrutinib users developed new or worsened HTN over a median of 30 months. New HTN developed in 71.6% of ibrutinib users, with a time to 50% cumulative incidence of 4.2 months. Among those without preceding HTN, 17.7% developed high-grade HTN (BP >160/100 mm Hg). In multivariate regression, new or worsened HTN was associated with increased MACEs (hazard ratio HR, 2.17; 95% confidence interval CI, 1.08-4.38). No single antihypertensive class was associated with prevention or control of ibrutinib-related HTN. However, antihypertensive initiation was associated with a lower risk of a MACE (HR, 0.40; 95% CI, 0.24-0.66). Collectively, these data suggest that ibrutinib is associated with a substantial increase in the incidence and severity of HTN, and that HTN development carries a higher risk of subsequent cardiotoxic events.
•Among lymphoid malignancy patients treated with ibrutinib, the subsequent incidence of new hypertension is nearly 72%.•Development of new or worsened HTN after ibrutinib initiation associates with a more than twofold increased risk of other cardiac events.
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Targeted therapies including the engineered afucosylated anti-CD20 monoclonal antibody obinutuzumab, Bruton's tyrosine kinase inhibitor ibrutinib, and B-cell lymphoma protein 2 inhibitor venetoclax ...have demonstrated significant clinical activity in chronic lymphocytic leukemia (CLL) and, based on their complementary mechanisms, are ideal for combination. However, combining venetoclax with other active agents raises safety concerns, as it may increase the risk for tumor lysis syndrome. To minimize this risk, we designed and implemented a fixed-duration regimen using sequentially administered obinutuzumab followed by ibrutinib (cycle 2) and venetoclax (cycle 3), for a total of fourteen 28-day cycles. This phase 1b study included 12 patients with relapsed or refractory CLL. We tested 3 dose levels of venetoclax and identified the doses of all 3 agents approved by the US Food and Drug Administration for use in the combination. Adverse events were consistent with known toxicities of the individual agents, with hematologic adverse events being most frequent. No clinically significant tumor lysis syndrome occurred. The overall response rate was 92% (95% confidence interval, 62%-100%), with 42% (5/12) achieving a complete remission or complete remission with incomplete marrow recovery. There were 6 patients with no detectable CLL in both the blood and bone marrow at the end of treatment. We found this regimen to be safe and tolerable in CLL, and capable of inducing deep responses, justifying future study in our ongoing phase 2 cohorts of relapsed or refractory and treatment-naive patients, as well as larger phase 3 trials currently in planning. This trial was registered at www.clinicaltrials.gov as #NCT02427451.
•Cytoreduction with obinutuzumab and ibrutinib followed by the addition of venetoclax has acceptable safety with no tumor lysis syndrome.•This combination has preliminary activity including complete remissions with undetectable residual disease in relapsed or refractory CLL.
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Therapeutic targeting of Bruton tyrosine kinase (BTK) has dramatically improved survival outcomes for patients with chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL). Acalabrutinib ...is an oral, highly selective BTK inhibitor that allows for twice-daily dosing due to its selectivity. In this phase 1b/2 study, 134 patients with relapsed/refractory CLL or SLL (median age, 66 years range, 42-85 years; median prior therapies, 2 range, 1-13) received acalabrutinib 100 mg twice daily for a median of 41 months (range, 0.2-58 months). Median trough BTK occupancy at steady state was 97%. Most adverse events (AEs) were mild or moderate, and were most commonly diarrhea (52%) and headache (51%). Grade ≥3 AEs (occurring in ≥5% of patients) were neutropenia (14%), pneumonia (11%), hypertension (7%), anemia (7%), and diarrhea (5%). Atrial fibrillation and major bleeding AEs (all grades) occurred in 7% and 5% of patients, respectively. Most patients (56%) remain on treatment; the primary reasons for discontinuation were progressive disease (21%) and AEs (11%). The overall response rate, including partial response with lymphocytosis, with acalabrutinib was 94%; responses were similar regardless of genomic features (presence of del(11)(q22.3), del(17)(p13.1), complex karyotype, or immunoglobulin variable region heavy chain mutation status). Median duration of response and progression-free survival (PFS) have not been reached; the estimated 45-month PFS was 62% (95% confidence interval, 51% to 71%). BTK mutation was detected in 6 of 9 patients (67%) at relapse. This updated and expanded study confirms the efficacy, durability of response, and long-term safety of acalabrutinib, justifying its further investigation in previously untreated and treated patients with CLL/SLL. This trial was registered at www.clinicaltrials.gov as #NCT02029443.
•At a median follow-up of 41 months, median PFS has not been reached in previously treated CLL patients on the BTK inhibitor acalabrutinib.•Patients with previously treated CLL or SLL had favorable safety, response, and durability of response with acalabrutinib.
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Over the past two decades, slow but deliberate progress has been made in understanding the genetics of chronic lymphocytic leukemia (CLL) and how the surrounding microenvironment influences leukemia ...cell survival. The complexity of CLL with respect to different chromosomal aberrations, lack of a common aberrant signaling pathway activation, and associated immune suppression of the disease has been seen a major stumbling block for developing a single targeted therapy similar to imatinib used in chronic myeloid leukemia. The upcoming therapeutic era we are entering with the B-cell receptor (BCR) tyrosine kinase inhibitors ibrutinib and idelalisib appears to be overcoming this obstacle. Indeed, for the large majority of patients, it appears that application of BCR kinase inhibitors can promote durable remissions without the need for chemotherapy. Where other very active targeted agents such as ABT-199, therapeutic antibodies, and chimeric antigen receptor-modified T-cells will be used in CLL also represents a major question that future clinical trials will answer.
The development of highly effective targeted agents for chronic lymphocytic leukemia offers the potential for fixed-duration combinations that achieve deep remissions without cytotoxic chemotherapy.
...This phase II study tested a combination regimen of obinutuzumab, ibrutinib, and venetoclax for a total of 14 cycles in both patients with treatment-naïve (n = 25) and relapsed or refractory (n = 25) chronic lymphocytic leukemia to determine the response to therapy and safety.
The primary end point was the rate of complete remission with undetectable minimal residual disease by flow cytometry in both the blood and bone marrow 2 months after completion of treatment, which was 28% in both groups. The overall response rate at that time was 84% in treatment-naïve patients and 88% in relapsed or refractory patients. At that time, 67% of treatment-naïve patients and 50% of relapsed or refractory patients had undetectable minimal residual disease in both the blood and marrow. At a median follow-up of 24.2 months in treatment-naïve patients and 21.5 months in relapsed or refractory patients, the median progression-free and overall survival times were not yet reached, with only 1 patient experiencing progression and 1 death. Neutropenia and thrombocytopenia were the most frequent adverse events, followed by hypertension. Grade 3 or 4 neutropenia was experienced by 66% of patients, with more events in the relapsed or refractory cohort. There was only 1 episode of neutropenic fever. A favorable impact on both perceived and objective cognitive performance during treatment was observed.
The combination regimen of obinutuzumab, ibrutinib, and venetoclax offers time-limited treatment that results in deep remissions and is now being studied in phase III cooperative group trials.
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