Safety and efficacy of zandelisib plus zanubrutinib in previously treated follicular and mantle cell lymphomas.

The combination of the phosphatidylinositol 3-kinase delta (PI3Kδ) inhibitor zandelisib with the Bruton's tyrosine kinase (BTK) inhibitor zanubrutinib was hypothesized to be synergistic and prevent resistance to single-agent therapy. This phase 1 study (NCT02914938) included a dose-finding stage in patients with relapsed/refractory (R/R) B-cell malignancies (n = 20) and disease-specific expansion cohorts in follicular lymphoma (FL; n = 31) or mantle cell lymphoma (MCL; n = 19). The recommended phase 2 dose was zandelisib 60 mg on Days 1-7 plus zanubrutinib 80 mg twice daily continuously in 28-day cycle. In the total population, the most common adverse events (AEs; all grades/grade 3-4) were neutropenia (35%/24%), diarrhoea (33%/2%), thrombocytopenia (32%/8%), anaemia (27%/8%), increased creatinine (25%/0%), contusion (21%/0%), fatigue (21%/2%), nausea (21%/2%) and increased aspartate aminotransferase (24%/6%). Three patients discontinued due to AEs. The overall response rate was 87% (complete response [CR] = 33%) for FL and 74% (CR = 47%) for MCL. The median duration of response and progression-free survival (PFS) were not reached in either group. The estimated 1-year PFS was 72.3% (95% confidence interval [CI], 51.9-85.1) for FL and 56.3% (95% CI, 28.9-76.7) for MCL (median follow-up: 16.5 and 10.9 months respectively). Zandelisib plus zanubrutinib was associated with high response rates and no increased toxicity compared to either agent alone.

Zanubrutinib in relapsed/refractory mantle cell lymphoma: long-term efficacy and safety results from a phase 2 study.

Bruton tyrosine kinase (BTK) inhibitor is an established treatment for relapsed/refractory (R/R) mantle cell lymphoma (MCL). Zanubrutinib, a highly selective BTK inhibitor, is approved for patients with MCL who have received ≥1 prior therapy. We report the long-term safety and efficacy results from the multicenter, open-label, phase 2 registration trial of zanubrutinib. Patients (n = 86) received oral zanubrutinib 160 mg twice daily. The primary endpoint was the overall response rate (ORR), assessed per Lugano 2014. After a median follow-up of 35.3 months, the ORR was 83.7%, with 77.9% achieving complete response (CR); the median duration of response was not reached. Median progression-free survival (PFS) was 33.0 months (95% confidence interval [CI], 19.4-NE). The 36-month PFS and overall survival (OS) rates were 47.6% (95% CI, 36.2-58.1) and 74.8% (95% CI, 63.7-83.0), respectively. The safety profile was largely unchanged with extended follow-up. Most common (≥20%) all-grade adverse events (AEs) were neutrophil count decreased (46.5%), upper respiratory tract infection (38.4%), rash (36.0%), white blood cell count decreased (33.7%), and platelet count decreased (32.6%); most were grade 1/2 events. Most common (≥10%) grade ≥3 AEs were neutrophil count decreased (18.6%) and pneumonia (12.8%). Rates of infection, neutropenia, and bleeding were highest in the first 6 months of therapy and decreased thereafter. No cases of atrial fibrillation/flutter, grade ≥3 cardiac AEs, second primary malignancies, or tumor lysis syndrome were reported. After extended follow-up, zanubrutinib demonstrated durable responses and a favorable safety profile in R/R MCL. The trial is registered at ClinicalTrials.gov as NCT03206970.

Effect of assessing velocity time integral at different locations across ventricular outflow tracts when calculating cardiac output in neonates.

This study aims to evaluate the effect of assessing velocity time integral at different locations across ventricular outflow tracts for calculating cardiac output (CO) in neonates. Velocity time integral (VTI) and CO were measured at 3 different locations across right and left ventricular outflow tracts using transthoracic echocardiography in healthy term neonates without any major congenital heart disease. ANOVA with Bonferroni correction was used to determine the differences between the VTI and CO sampled at these three locations. Forty-one neonates met inclusion criteria with mean gestational age of 38.6 ± 1 weeks and mean birth weight of 3155 ± 463 g. The median hours after birth when echocardiography was obtained was 23 h (range 11-68 h after birth). Left CO were 121 ± 30 mL/kg/min, 155 ± 38 mL/kg/min, and 176 ± 36 mL/kg/min measured below the valve, hinges of the valve, and tip of the valve, respectively. Right CO were 197 ± 73 mL/kg/min, 270 ± 83 mL/kg/min, and 329 ± 104 mL/kg/min measured below the valve, hinges of the valve, and tip of the valve, respectively. A statistically significant difference (P < 0.001) was found in the VTI and CO measured at the 3 different locations across both left and right ventricular outflow tracts.     Conclusions: There is a significant difference in measurements of VTI and CO depending on the location of Doppler gate sampling across the ventricular outflow tracts. Consistency and precision in Doppler gate location are essential for measuring VTI and calculating CO while assessing changes in hemodynamic status in critically ill infants. What is Known: • Targeted Neonatal Echocardiography is increasingly applied to measure cardiac output in critically ill neonates and serial assessments are performed to assess the trend in changes in cardiac output. • Noninvasive measurement using velocity time integral to calculate cardiac output is commonly performed. However, location of Doppler sample gate to measure ventricular outflow tract velocity time integral is not consistent. What is New: • Statistically significant changes in measured velocity time integral and cardiac output are noted based on the location of Doppler gate sampling. • To monitor the cardiac output for trending, it is important to be consistent with regards to the location of the Doppler sample gate to assess changes in cardiac output in critically ill newborns.

Zanubrutinib versus bendamustine and rituximab in untreated chronic lymphocytic leukaemia and small lymphocytic lymphoma (SEQUOIA): a randomised, controlled, phase 3 trial.

BACKGROUND: Zanubrutinib is a next-generation, selective Bruton tyrosine kinase inhibitor with efficacy in relapsed chronic lymphocytic leukemia (CLL) and small lymphocytic lymphoma (SLL). We compared zanubrutinib with bendamustine-rituximab to determine its effectiveness as frontline therapy in patients with CLL or SLL. METHODS: We conducted an open-label, multicentre, phase 3 study at 153 academic or community hospitals in 14 countries and regions. Eligible patients had untreated CLL or SLL requiring treatment as per International Workshop on CLL criteria; were aged 65 years or older, or 18 years or older and had comorbidities; and had an Eastern Cooperative Oncology Group performance status score of 0-2. A central interactive web response system randomly assigned patients without del(17)(p13·1) to zanubrutinib (group A) or bendamustine-rituximab (group B) by sequential block method (permutated blocks with a random block size of four). Patients with del(17)(p13·1) were enrolled in group C and received zanubrutinib. Zanubrutinib was administered orally at 160 mg twice per day (28-day cycles); bendamustine at 90 mg/m2 of body surface area on days 1 and 2 for six cycles plus rituximab at 375 mg/m2 of body surface area the day before or on day 1 of cycle 1, and 500 mg/m2 of body surface area on day 1 of cycles 2-6, were administered intravenously. The primary endpoint was progression-free survival per independent review committee in the intention-to-treat population in groups A and B, with minimum two-sided α of 0·05 for superiority. Safety was analysed in all patients who received at least one dose of study treatment. The study is registered with ClinicalTrials.gov, NCT03336333, and is closed to recruitment. FINDINGS: Between Oct 31, 2017, and July 22, 2019, 590 patients were enrolled; patients without del(17)(p13·1) were randomly assigned to zanubrutinib (group A; n=241) or bendamustine-rituximab (group B; n=238). At median follow-up of 26·2 months (IQR 23·7-29·6), median progression-free survival per independent review committee was not reached in either group (group A 95% CI not estimable [NE] to NE; group B 28·1 months to NE). Progression-free survival was significantly improved in group A versus group B (HR 0·42 [95% CI 0·28 to 0·63]; two-sided p<0·0001). The most common grade 3 or worse adverse event was neutropenia (27 [11%] of 240 patients in group A, 116 [51%] of 227 in group B, and 17 [15%] of 111 patients in group C). Serious adverse events occurred in 88 (37%) of 240 patients in group A, 113 (50%) of 227 patients in group B, and 45 (41%) of 111 patients in group C. Adverse events leading to death occurred in 11 (5%) of 240 patients in group A, 12 (5%) of 227 patients in group B, and three (3%) of 111 patients in group C, most commonly due to COVID-19 (four [2%] of 240 patients in group A), diarrhoea, and aspiration pneumonia (two each [1%] of 227 patients in group B). INTERPRETATION: Zanubrutinib significantly improved progression-free survival versus bendamustine-rituximab, with an acceptable safety profile consistent with previous studies. These data support zanubrutinib as a potential new treatment option for untreated CLL and SLL. FUNDING: BeiGene.

A two-part, single-arm, multicentre, phase I study of zanubrutinib, a selective Bruton tyrosine kinase inhibitor, in Chinese patients with relapsed/refractory B-cell malignancies.

This single-arm, multicentre, phase I study is the first study of zanubrutinib, a potent, specific, irreversible Bruton tyrosine kinase (BTK) inhibitor, in Chinese patients with relapsed/refractory B-cell malignancies. The objectives were to evaluate safety and preliminary anti-tumour activity. Forty-four patients received zanubrutinib 320 mg once daily (QD) (n = 10) or 160 mg twice daily (BID) (n = 34) until disease progression or unacceptable toxicity. 29.5% of patients received zanubrutinib for at least two years. The most common adverse event (AE) and the most common grade 3 or higher AE was neutrophil count decreased (54.5% and 25.0% respectively). Two patients (4.5%) discontinued treatment due to AEs and one treatment-emergent AE led to death. All haemorrhagic events were grade 1-2 (except for one non-serious grade 3 purpura). No second primary malignancies, tumour lysis syndrome, or atrial fibrillation/flutter occurred. The overall response rate was 52.3% (complete response rate, 18.2%). Patients with all cancer subtypes benefited from treatment. BTK C481S/R or L528W mutations were found in zanubrutinib-progressive patients. The safety/efficacy profiles of patients treated with 320 mg QD and 160 mg BID were comparable and similar daily area under the curve (AUC) was achieved. Overall, zanubrutinib was well tolerated and either of these two regimens is clinically practical. Registered at ClinicalTrials.gov (NCT03189524, on 16 June 2017, https://clinicaltrials.gov/ct2/show/NCT03189524).

Zanubrutinib for treatment-naïve and relapsed/refractory chronic lymphocytic leukaemia: long-term follow-up of the phase I/II AU-003 study.

The phase I/II AU-003 study in patients with treatment-naïve (TN) or relapsed/refractory (R/R) chronic lymphocytic leukaemia/small lymphocytic lymphoma demonstrated that zanubrutinib therapy results in clinically meaningful and durable responses with acceptable safety and tolerability. We report updated safety and efficacy data for 123 patients with a median follow-up of 47·2 months. Patients received zanubrutinib 160 mg twice daily (81 patients), 320 mg once daily (40), or 160 mg once daily (two). Discontinuations due to adverse events or disease progression were uncommon. The overall response rate (ORR) was 95·9% (TN, 100%; R/R, 95%) with 18·7% achieving complete response (CR). Ongoing response at 3 years was reported in 85·7%. The ORR in patients with del(17p)/tumour protein p53 mutation was 87·5% (CR 16·7%). The 2- and 3-year progression-free survival estimates were 90% (TN, 90%; R/R, 91%) and 83% (TN, 81%; R/R, 83%) respectively. The most reported Grade ≥3 adverse events were neutropenia (15·4%), pneumonia (9·8%), hypertension (8·9%) and anaemia (6·5%). The annual incidence of atrial fibrillation, major haemorrhage, Grade ≥3 neutropenia and Grade ≥3 infection decreased over time. With a median follow-up of ~4 years, responses remain clinically meaningful and durable and long-term tolerability to zanubrutinib therapy continues.

Zanubrutinib for the treatment of patients with Waldenström macroglobulinemia: 3 years of follow-up.

Inhibitors of Bruton's tyrosine kinase (BTK) have established therapeutic activity in patients with Waldenström macroglobulinemia (WM). Zanubrutinib, a potent and selective BTK inhibitor, was evaluated in a phase 1/2 study in patients with WM who were either treatment-naïve (TN) or had relapsed/refractory (R/R) disease. Patients had disease requiring treatment per International Workshop on Waldenström Macroglobulinemia (IWWM) criteria. Treatment was 160 mg of oral zanubrutinib twice daily (n = 50) or 320 mg once daily (n = 23). Efficacy endpoints included overall response rate (ORR) and very good partial response/complete response (VGPR/CR) rates per IWWM-6 criteria (with modification of VGPR definition published previously). Between September 2014 and March 2018, 77 patients (24 TN and 53 R/R) began treatment. At a median follow-up of 36.0 months for patients with R/R disease and 23.5 months for TN, 72.7% remained on treatment. Reasons for treatment discontinuation included any adverse events in 13.0% of patients (1 treatment related), disease progression (10.4%), and other (3.9%). The ORR was 95.9%, and the VGPR/CR rate was 45.2%, which increased over time: 20.5% at 6 months, 32.9% at 12 months, and 43.8% at 24 months. Estimated 3-year progression-free survival rate was 80.5%, and overall survival rate was 84.8%. Adverse events of interest included contusion (32.5%, all grade 1), neutropenia (18.2%), major hemorrhage (3.9%), atrial fibrillation/flutter (5.2%), and grade 3 diarrhea (2.6%). Long-term treatment with single-agent zanubrutinib resulted in deep and durable responses in some patients with WM. The safety profile of long-term zanubrutinib therapy in these patients was acceptable. This trial was registered at www.clinicaltrials.gov as #NCT02343120.

A randomized phase 3 trial of zanubrutinib vs ibrutinib in symptomatic Waldenström macroglobulinemia: the ASPEN study.

Bruton tyrosine kinase (BTK) inhibition is an effective treatment approach for patients with Waldenström macroglobulinemia (WM). The phase 3 ASPEN study compared the efficacy and safety of ibrutinib, a first-generation BTK inhibitor, with zanubrutinib, a novel highly selective BTK inhibitor, in patients with WM. Patients with MYD88L265P disease were randomly assigned 1:1 to treatment with ibrutinib or zanubrutinib. The primary end point was the proportion of patients achieving a complete response (CR) or a very good partial response (VGPR) by independent review. Key secondary end points included major response rate (MRR), progression-free survival (PFS), duration of response (DOR), disease burden, and safety. A total of 201 patients were randomized, and 199 received ≥1 dose of study treatment. No patient achieved a CR. Twenty-nine (28%) zanubrutinib patients and 19 (19%) ibrutinib patients achieved a VGPR, a nonstatistically significant difference (P = .09). MRRs were 77% and 78%, respectively. Median DOR and PFS were not reached; 84% and 85% of ibrutinib and zanubrutinib patients were progression free at 18 months. Atrial fibrillation, contusion, diarrhea, peripheral edema, hemorrhage, muscle spasms, and pneumonia, as well as adverse events leading to treatment discontinuation, were less common among zanubrutinib recipients. Incidence of neutropenia was higher with zanubrutinib, although grade ≥3 infection rates were similar in both arms (1.2 and 1.1 events per 100 person-months). These results demonstrate that zanubrutinib and ibrutinib are highly effective in the treatment of WM, but zanubrutinib treatment was associated with a trend toward better response quality and less toxicity, particularly cardiovascular toxicity.

A clinical practice comparison of patients with chronic lymphocytic leukemia with and without deletion 17p receiving first-line treatment with ibrutinib.

Among patients with chronic lymphocytic leukemia (CLL) with deletion 17p (del[17p]), evidence from clinical trials for the effectiveness of single-agent ibrutinib as first-line therapy is limited. This retrospective analysis compared real-world clinical outcomes among patients with CLL, with and without del(17p), treated with first-line ibrutinib monotherapy. Overall survival, time to next treatment, time to treatment discontinuation, and reasons for ibrutinib discontinuation were evaluated. Using data from a real-world database, patients included were aged ≥18 years, had been diagnosed with CLL between January 1, 2011 and December 31, 2019, had undergone cytogenetic testing, and had received first-line ibrutinib monotherapy. A total of 1,069 patients were included in the analysis (62.7% male; median age 69 years); 23.8% (n=254) had del(17p). The median overall survival was significantly shorter in patients with del(17p) than in patients without (57.7 months vs. not reached; P=0.0006). Similar results were observed for median time to next treatment (49.4 months vs. not reached, P=0.0330). The median time to treatment discontinuation was non-significantly shorter in the group of patients with del(17p) (32.5 months vs. 42.9 months, P=0.3370). Results of an adjusted Cox proportional hazards model showed that the group with del(17p) was at significantly higher risk of death than was the group without del(17p) (hazard ratio=1.70, P=0.0031). Event rates for switching to new treatment and discontinuation were higher but not statistically significantly so. The most common reason for discontinuing ibrutinib treatment in both groups was toxicity, but discontinuation due to progression was significantly more frequent among patients with del(17p) (20% vs. 6%; P<0.0001). This study identifies an unmet need for more effective first-line therapeutic options in patients with CLL/small lymphocytic lymphoma and del(17p), despite the advent of ibrutinib.

Phase 1 study of the selective BTK inhibitor zanubrutinib in B-cell malignancies and safety and efficacy evaluation in CLL.

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.

A Phase III study of zanubrutinib plus rituximab versus bendamustine plus rituximab in transplant-ineligible, untreated mantle cell lymphoma.

Mantle cell lymphoma is an aggressive B-cell malignancy. Current frontline chemoimmunotherapies produce high response rates but relapse is inevitable. Furthermore, the elderly and those with comorbidities are precluded from standard regimens and stem cell transplant, leaving them with limited options. Targeted therapies, including Bruton tyrosine kinase inhibitors, are an effective treatment strategy in mantle cell lymphoma. Zanubrutinib is a potent next-generation Bruton tyrosine kinase inhibitor that has demonstrated complete and sustained Bruton tyrosine kinase occupancy, minimal off-target effects and favorable pharmacokinetic/pharmacodynamic properties. Described herein is an ongoing Phase III study comparing the efficacy and safety of zanubrutinib plus rituximab followed by zanubrutinib monotherapy versus bendamustine plus rituximab followed by observation in transplant-ineligible patients with previously untreated mantle cell lymphoma. Clinical Trial Registration: NCT04002297 (ClinicalTrials.gov).

Zanubrutinib monotherapy for patients with treatment naïve chronic lymphocytic leukemia and 17p deletion.

Patients with chronic lymphocytic leukemia or small lymphocytic lymphoma whose tumors carry deletion of chromosome 17p13.1 [del(17p)] have an unfavorable prognosis and respond poorly to standard chemoimmunotherapy. Zanubrutinib is a selective next-generation Bruton tyrosine kinase inhibitor. We evaluated the safety and efficacy of zanubrutinib 160 mg twice daily in treatment-naïve patients with del(17p) disease enrolled in a dedicated, nonrandomized cohort (Arm C) of the phase 3 SEQUOIA trial. A total of 109 patients (median age, 70 years; range, 42 - 86) with centrally confirmed del(17p) were enrolled and treated. After a median of 18.2 months (range, 5.0 - 26.3), seven patients had discontinued study treatment due to progressive disease, four due to an adverse event, and one due to withdrawal of consent. The overall response rate was 94.5% with 3.7% of patients achieving complete response with or without incomplete hematologic recovery. The estimated 18-month progression-free survival rate was 88.6% (95% CI, 79.0 - 94.0) and the estimated 18-month overall survival rate was 95.1% (95% CI, 88.4 - 98.0). Most common all-grade adverse events included contusion (20.2%), upper respiratory tract infection (19.3%), neutropenia/neutrophil count decreased (17.4%), and diarrhea (16.5%). Grade ≥ 3 adverse events were reported in 53 patients (48.6%), most commonly neutropenia (12.9%) and pneumonia (3.7%). An adverse event of atrial fibrillation was reported in three patients (2.8%). Zanubrutinib was active and well tolerated in this large, prospectively enrolled treatment cohort of previously untreated patients with del(17p) chronic lymphocytic leukemia/small lymphocytic lymphoma. This trial was registered at ClinicalTrials.gov as #NCT03336333.

Effect of high nucleated cell concentration on product viability and hematopoietic recovery in autologous transplantation.

BACKGROUND: Administering lower total product volumes with high nucleated cell (NC) concentrations may have the potential benefit of decreasing volume- and dimethyl sulfoxide (DMSO)-related patient complications, while maximizing the laboratory's freezer storage capacity. Our study is a retrospective investigation of the effect of HPC(A) products with cell concentrations greater than 3 × 108 NC/mL on clinical and product outcomes in patients undergoing autologous peripheral blood stem cell (PBSC) transplantation. STUDY DESIGN AND METHODS: A total of 113 consecutive patients with hematological malignancies who underwent autologous PBSC transplantation were included in this retrospective analysis. The primary outcomes were days to initial absolute neutrophil count (ANC) recovery and initial platelet recovery. The secondary outcomes included the storage duration, segment thaw viability, and dose of viable CD34+ cells/kg administered. RESULTS: Of 92 patients and 176 apheresis procedures, 81 patients received HPC(A) products with high NC concentration (4.1 × 108 NC/mL), and 11 patients received low NC concentration products (2.4 × 108 NC/mL). There were no observed differences in clinical outcomes with respect to ANC recovery (14 vs. 14 vs. 12 days) and platelet recovery (16 vs. 16 vs. 15 days) when very high NC (5.2 × 108 NC/mL) and high NC (4.1 × 108 NC/mL) groups were compared to the low NC group (2.4 × 108 NC/mL). CONCLUSION: Our retrospective investigation provides further supporting evidence that HPC(A) products with cell concentration greater than 3 × 108 NC/mL did not show detrimental effects on the clinical outcomes in patients undergoing autologous PBSC transplantation.

ALPINE: zanubrutinib versus ibrutinib in relapsed/refractory chronic lymphocytic leukemia/small lymphocytic lymphoma.

Treatment standards for chronic lymphocytic leukemia (CLL) have been transformed with the advent of effective inhibitors of B-cell receptor signaling such as ibrutinib - a first-in-class inhibitor of BTK. Off-target kinase inhibitions by ibrutinib are thought to contribute to its adverse events. Zanubrutinib is a next-generation BTK inhibitor with minimal off-target effects, sustained BTK occupancy in peripheral blood mononuclear cells and lymph nodes from patients with B-cell malignancies and promising responses in patients with CLL. Described here is a head-to-head Phase III study comparing the efficacy and safety of zanubrutinib with those of ibrutinib in patients with CLL/small lymphocytic lymphoma in the relapsed/refractory setting.

Acalabrutinib (ACP-196) in Relapsed Chronic Lymphocytic Leukemia.

BACKGROUND: Irreversible inhibition of Bruton's tyrosine kinase (BTK) by ibrutinib represents an important therapeutic advance for the treatment of chronic lymphocytic leukemia (CLL). However, ibrutinib also irreversibly inhibits alternative kinase targets, which potentially compromises its therapeutic index. Acalabrutinib (ACP-196) is a more selective, irreversible BTK inhibitor that is specifically designed to improve on the safety and efficacy of first-generation BTK inhibitors. METHODS: In this uncontrolled, phase 1-2, multicenter study, we administered oral acalabrutinib to 61 patients who had relapsed CLL to assess the safety, efficacy, pharmacokinetics, and pharmacodynamics of acalabrutinib. Patients were treated with acalabrutinib at a dose of 100 to 400 mg once daily in the dose-escalation (phase 1) portion of the study and 100 mg twice daily in the expansion (phase 2) portion. RESULTS: The median age of the patients was 62 years, and patients had received a median of three previous therapies for CLL; 31% had chromosome 17p13.1 deletion, and 75% had unmutated immunoglobulin heavy-chain variable genes. No dose-limiting toxic effects occurred during the dose-escalation portion of the study. The most common adverse events observed were headache (in 43% of the patients), diarrhea (in 39%), and increased weight (in 26%). Most adverse events were of grade 1 or 2. At a median follow-up of 14.3 months, the overall response rate was 95%, including 85% with a partial response and 10% with a partial response with lymphocytosis; the remaining 5% of patients had stable disease. Among patients with chromosome 17p13.1 deletion, the overall response rate was 100%. No cases of Richter's transformation (CLL that has evolved into large-cell lymphoma) and only one case of CLL progression have occurred. CONCLUSIONS: In this study, the selective BTK inhibitor acalabrutinib had promising safety and efficacy profiles in patients with relapsed CLL, including those with chromosome 17p13.1 deletion. (Funded by the Acerta Pharma and others; ClinicalTrials.gov number, NCT02029443.).

Clinical Extrapolation of the Effects of Dolutegravir and Other HIV Integrase Inhibitors on Folate Transport Pathways.

Preliminary analysis of ongoing birth surveillance study identified evidence of potential increased risk for neural tube defects (NTDs) in newborns associated with exposure to dolutegravir at the time of conception. Folate deficiency is a common cause of NTDs. Dolutegravir and other HIV integrase inhibitor drugs were evaluated in vitro for inhibition of folate transport pathways: proton-coupled folate transporter (PCFT), reduced folate carrier (RFC), and folate receptor α (FRα)-mediated endocytosis. Inhibition of folate transport was extrapolated to the clinic by using established approaches for transporters in intestine, distribution tissues, and basolateral and apical membranes of renal proximal tubules (2017 FDA Guidance). The positive controls, methotrexate and pemetrexed, demonstrated clinically relevant inhibition of PCFT, RFC, and FRα in folate absorption, distribution, and renal sparing. Valproic acid was used as a negative control that elicits folate-independent NTDs; valproic acid did not inhibit PCFT, RFC, or FRα At clinical doses and exposures, the observed in vitro inhibition of FRα by dolutegravir and cabotegravir was not flagged as clinically relevant; PCFT and RFC inhibition was not observed in vitro. Bictegravir inhibited both PCFT and FRα, but the observed inhibition did not reach the criteria for clinical relevance. Elvitegravir and raltegravir inhibited PCFT, but only raltegravir inhibition of intestinal PCFT was flagged as potentially clinically relevant at the highest 1.2-g dose (not the 400-mg dose). These studies showed that dolutegravir is not a clinical inhibitor of folate transport pathways, and it is not predicted to elicit clinical decreases in maternal and fetal folate levels. Clinically relevant HIV integrase inhibitor drug class effect on folate transport pathways was not observed. SIGNIFICANCE STATEMENT: Preliminary analysis of ongoing birth surveillance study identified evidence of potential increased risk for neural tube defects (NTDs) in newborns associated with exposure to the HIV integrase inhibitor dolutegravir at the time of conception; folate deficiency is a common cause of NTDs. Dolutegravir and other HIV integrase inhibitor drugs were evaluated in vitro for inhibition of the major folate transport pathways: proton-coupled folate transporter, reduced folate carrier, and folate receptor α-mediated endocytosis. The present studies showed that dolutegravir is not a clinical inhibitor of folate transport pathways, and it is not predicted to elicit clinical decreases in maternal and fetal folate levels. Furthermore, clinically relevant HIV integrase inhibitor drug class effect on folate transport pathways was not observed.

A head-to-head Phase III study comparing zanubrutinib versus ibrutinib in patients with Waldenström macroglobulinemia.

Waldenström macroglobulinemia (WM), an incurable B-cell malignancy, is sensitive to Bruton tyrosine kinase (BTK) inhibition with ibrutinib, a first-generation BTK inhibitor. Off-target effects of ibrutinib against TEC- and EGFR-family kinases are implicated in some adverse events. Patients with CXCR4WHIM and MYD88L265P mutations or who are MYD88WT have less sensitivity to ibrutinib than those with MYD88L265P and CXCR4WT disease. Zanubrutinib, a next-generation BTK inhibitor with potent preclinical activity in WM and minimal off-target effects, showed sustained BTK occupancy in peripheral blood mononuclear cells from patients with B-cell malignancies and promising responses in advanced WM. Described here is a head-to-head Phase III study comparing efficacy and safety of zanubrutinib and ibrutinib in WM patients. Effect of MYD88 and CXCR4 mutation status will be assessed.

Neurotrophic factor-α1 modulates NGF-induced neurite outgrowth through interaction with Wnt-3a and Wnt-5a in PC12 cells and cortical neurons.

Wnt-3a and Wnt-5a signaling activities inhibit and promote neurite outgrowth, respectively, to regulate dendritic and axonal genesis during neurodevelopment. NF-α1, a neurotrophic factor, has been shown to modulate dendritic remodeling and negatively regulate the canonical Wnt-3a pathway. Here, we investigated whether NF-α1 could modify nerve growth factor (NGF)-induced neurite outgrowth through interaction with Wnt-3a and Wnt-5a in PC12 cells and mouse primary cortical neurons. We showed that NGF-induced neurite outgrowth was inhibited by Wnt-3a, and this inhibition was prevented by NF-α1. Western blot analysis revealed that NF-α1 reduced the expression of both ß-catenin in the canonical Wnt-3a pathway and Rho, a downstream effector of Wnt-3a's non-canonical signaling pathway. Treatment of PC12 cells with a ROCK inhibitor prevented the inhibition of NGF-induced neurite outgrowth by Wnt-3a, suggesting that NF-α1 promotes neurite outgrowth in the presence of Wnt-3a by down-regulating its canonical and non-canonical activities. Interestingly, treatment of PC12 cells with Wnt-5a, which formed a complex with NF-α1, induced neurite outgrowth that was enhanced by treatment with the combination of Wnt-5a, NGF, and NF-α1. These effects of NF-α1 on Wnt 3a's and Wnt 5a's regulation of neurite outgrowth in PC12 cells were also demonstrated in primary cultures of mouse cortical neurons. In addition, we showed in PC12 cells that NF-α1 acts by upregulating adenomatous polyposis coli (APC) accumulation at neurite tips, thereby providing positive and negative Wnt-3a/Wnt-5a mediated cues to modulate neurite outgrowth, a process important during neurodevelopment.

Impact on creatinine renal clearance by the interplay of multiple renal transporters: a case study with INCB039110.

Serum creatinine is commonly used as a marker of renal function, but increases in serum creatinine might not represent changes in glomerular filtration rate (GFR). INCB039110 (2-(3-(4-(7H-pyrrolo[2,3-day]pyrimidin-4-yl)-1H-pyrazol-1-yl)-1-(1-(3-fluoro-2-(trifluoromethyl)isonicotinoyl)piperidin-4-yl)azetidin-3-yl)acetonitrile) is an inhibitor of the Janus kinases (JAKs) with selectivity for JAK1. In a phase 1 study, a modest and reversible increase in serum creatinine was observed after treatment with INCB039110. However, a dedicated renal function study with INCB039110, assessed by iohexol plasma clearance, conducted in healthy volunteers indicated no change in GFR. In vitro studies were therefore conducted to investigate the interaction of INCB039110 with five transporters that are likely involved in the renal clearance of creatinine. Cell systems expressing individual or multiple transporters were used, including a novel quintuple-transporter model OAT2/OCT2/OCT3/MATE1/MATE2-K. INCB039110 potently inhibited OCT2-mediated uptake of creatinine as well as MATE1-/MATE2-K-mediated efflux of creatinine. Given the interactions of INCB039110 with multiple transporters affecting creatinine uptake and efflux, an integrated system expressing all five transporters was sought; in that system, INCB039110 caused a dose-dependent decrease in transcellular transport of creatinine with weaker net inhibition compared with the effects on individual transporters. In summary, a molecular mechanism for the increase in serum creatinine by INCB039110 has been established. These studies also underline the limitations of using serum creatinine as a marker of renal function.

Contribution of the organic anion transporter OAT2 to the renal active tubular secretion of creatinine and mechanism for serum creatinine elevations caused by cobicistat.

Many xenobiotics including the pharmacoenhancer cobicistat increase serum creatinine by inhibiting its renal active tubular secretion without affecting the glomerular filtration rate. This study aimed to define the transporters involved in creatinine secretion, applying that knowledge to establish the mechanism for xenobiotic-induced effects. The basolateral uptake transporters organic anion transporter OAT2 and organic cation transporters OCT2 and OCT3 were found to transport creatinine. At physiologic creatinine concentrations, the specific activity of OAT2 transport was over twofold higher than OCT2 or OCT3, establishing OAT2 as a likely relevant creatinine transporter and further challenging the traditional view that creatinine is solely transported by a cationic pathway. The apical multidrug and toxin extrusion transporters MATE1 and MATE2-K demonstrated low-affinity and high-capacity transport. All drugs known to affect creatinine inhibited OCT2 and MATE1. Similar to cimetidine and ritonavir, cobicistat had the greatest effect on MATE1 with a 50% inhibition constant of 0.99 µM for creatinine transport. Trimethoprim potently inhibited MATE2-K, whereas dolutegravir preferentially inhibited OCT2. Cimetidine was unique, inhibiting all transporters that interact with creatinine. Thus, the clinical observation of elevated serum creatinine in patients taking cobicistat is likely a result of OCT2 transport, facilitating intracellular accumulation, and MATE1 inhibition.