Project description:PurposeAlthough Bruton tyrosine kinase (BTK) inhibitors have demonstrated promising efficacy in patients with Waldenström macroglobulinemia (WM), data in Asian populations are scarce. This trial is the first to investigate the effect of a BTK inhibitor in Chinese patients with relapsed/refractory (R/R) WM.Patients and methodsPatients with R/R WM with at least one prior regimen were enrolled into this single-arm, multicenter, phase II study (NCT03332173) and received zanubrutinib 160 mg twice daily until disease progression or unacceptable toxicity. The primary endpoint was major response rate (MRR), as assessed by an independent review committee. Secondary endpoints included progression-free survival, overall response rate, duration of major response, and safety.ResultsForty-four patients were enrolled. After a median follow-up of 33.0 (range, 3.2-36.5) months, MRR in all patients was 69.8%, with very good partial response or better in 32.6% of patients. All mutation groups benefited from zanubrutinib treatment (MRR in patients with MYD88 L265P mutation, 73%; MRR in patients with MYD88 wild type mutation, 50%). A higher response rate was seen in the MYD88 L265P/CXCR4 WT population, compared with the other populations. Median progression-free survival and median duration of major response were not reached. The most frequently reported grade ≥3 treatment-emergent adverse events (AEs) were neutrophil count decreased (31.8%), and platelet count decreased and pneumonia (20.5% each). No case of atrial fibrillation/flutter occurred.ConclusionsZanubrutinib achieved a high rate of response that was durable and deep in patients with R/R WM across all subgroups, and potentially confers a positive benefit-risk profile for WM.
Project description:The understanding of the B cell receptor (BCR) pathway and its contribution to chronic lymphocytic leukemia (CLL) pathogenesis have led to the development of targeted BCR inhibitors which have transformed the treatment paradigm of CLL. Ibrutinib is a first-in-class oral Bruton's tyrosine kinase (BTK) inhibitor which has demonstrated improvements in both progression free (PFS) and overall survival (OS) in both the treatment naïve and relapsed/refractory setting as compared to traditional chemoimmunotherapy. Despite its clinical efficacy, many patients discontinue treatment due to adverse events, which are thought to be mediated through off-target kinase inhibition. Zanubrutinib is a second-generation non-covalent BTK inhibitor with higher potency, allowing for inhibition of BTK with fewer off target effects. Early phase clinical trials have demonstrated excellent efficacy and a well-tolerated safety profile. Long-term follow-up is needed, but zanubrutinib holds promise to be an effective therapy for CLL with a manageable side effect profile and will be an exciting addition to our treatment paradigm.
Project description:Chronic myeloid leukemia (CML) is currently a disease in which patients can enjoy a near normal life-expectancy. However, since the majority of patients will need to remain on treatment indefinitely, physicians in care of CML patients need be familiar with the indications and toxicities of all approved tyrosine kinase inhibitors (TKI). In clinical practice, there are five TKI (imatinib, nilotinib, dasatinib, bosutinib, and ponatinib) that are available in different scenarios and have distinct safety profiles. Decisions regarding first line treatment must be based on CML risk, comorbidities, and patients expectations. Despite the excellent outcome, half of the patients will eventually fail (due to intolerance or resistance) to first line treatment, with many of them requiring a third or even further lines of therapy. When selecting for such patients, it is essential to distinguish between failure and intolerance to previous TKIs. In the present review, we will address all these issues from a practical point of view.
Project description:PurposeZanubrutinib (BGB-3111) is a potent Bruton's tyrosine kinase inhibitor with promising clinical activity in B-cell malignancies. Zanubrutinib was shown to be mainly metabolized through cytochrome P450 3A (CYP3A) in vitro. We evaluated the effect of steady-state rifampin (a strong CYP3A inducer) and steady-state itraconazole (a strong CYP3A inhibitor) on the pharmacokinetics (PK), safety, and tolerability of zanubrutinib in healthy Asian and non-Asian subjects.MethodsIn this open-label, two-part clinical study, 20 participants received a single oral dose of zanubrutinib (320 mg) and oral rifampin (600 mg) in Part A, and 18 participants received a single oral dose of zanubrutinib (20 mg) and oral itraconazole (200 mg) in Part B. Serial blood samples were collected after administration of zanubrutinib alone and zanubrutinib in combination with rifampin or itraconazole for the measurement of PK parameters.ResultsCoadministration with rifampin decreased AUC0-∞ of zanubrutinib by 13.5-fold and Cmax by 12.6-fold. Coadministration with itraconazole increased the AUC0-∞ of zanubrutinib by 3.8-fold and Cmax by 2.6-fold. The PK of zanubrutinib was consistent between Asian and non-Asian subjects, and zanubrutinib was well tolerated in this study.ConclusionsThese results confirm that zanubrutinib is primarily metabolized by CYP3A in humans. The PK of zanubrutinib was comparable between Asian and non-Asian subjects and, therefore, no dose modifications are necessary for zanubrutinib in these ethnic populations.
Project description:IntroductionThis network meta-analysis aims to deliver an up-to-date, comprehensive efficacy and toxicity comparison of the approved first-line tyrosine kinase inhibitors (TKIs) for metastatic renal cell carcinoma (mRCC) in order to provide support for evidence-based treatment decisions. Previous NMAs of first-line mRCC treatments either predate the approval of all the first-line TKIs currently available or do not include evaluation of safety data for all treatments.MethodsWe performed a systematic literature review and network meta-analysis of phase II/III randomised controlled trials (RCTs) assessing approved first-line TKI therapies for mRCC. A random effects model with a frequentist approach was computed for progression-free survival (PFS) data and for the proportion of patients experiencing a maximum of grade 3 or 4 adverse events (AEs).ResultsThe network meta-analysis of PFS demonstrated no significant differences between cabozantinib and either sunitinib (50 mg 4/2), pazopanib or tivozanib. The network meta-analysis indicated that in terms of grade 3 and 4 AEs, tivozanib had the most favourable safety profile and was associated with significantly less risk of toxicity than the other TKIs.ConclusionThese network meta-analysis data demonstrate that cabozantinib, sunitinib, pazopanib and tivozanib do not significantly differ in their efficacy, but tivozanib is associated with a more favourable safety profile in terms of grade 3 or 4 toxicities. Consequently, the relative toxicity of these first-line TKIs may play a more significant role than efficacy comparisons in treatment decisions and in planning future RCTs.
Project description:Zanubrutinib is a potent and highly selective inhibitor of Bruton tyrosine kinase (BTK). In this first-in-human, open-label, multicenter, phase 1 study, patients in part 1 (3 + 3 dose escalation) had relapsed/refractory B-cell malignancies and received zanubrutinib 40, 80, 160, or 320 mg once daily or 160 mg twice daily. Part 2 (expansion) consisted of disease-specific cohorts, including treatment-naive or relapsed/refractory chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). The primary end points were safety and tolerability, and definition of the maximum tolerated dose (part 1). Additional end points included pharmacokinetics/pharmacodynamics and preliminary efficacy. Reported herein are results from 144 patients enrolled in the dose-finding and CLL/SLL cohorts. No dose-limiting toxicities occurred in dose escalation. Median BTK occupancy in peripheral blood mononuclear cells was >95% at all doses. Sustained complete (>95%) BTK occupancy in lymph node biopsy specimens was more frequent with 160 mg twice daily than 320 mg once daily (89% vs 50%; P = .0342). Consequently, 160 mg twice daily was selected for further investigation. With median follow-up of 13.7 months (range, 0.4-30.5 months), 89 CLL/SLL patients (94.7%) remain on study. Most toxicities were grade 1/2; neutropenia was the only grade 3/4 toxicity observed in >2 patients. One patient experienced a grade 3 subcutaneous hemorrhage. Among 78 efficacy-evaluable CLL/SLL patients, the overall response rate was 96.2% (95% confidence interval, 89.2-99.2). Estimated progression-free survival at 12 months was 100%. Zanubrutinib demonstrated encouraging activity in CLL/SLL patients, with a low incidence of major toxicities. This trial was registered at www.clinicaltrials.gov as #NCT02343120.