Phase I dose‐escalation study of buparlisib (BKM120), an oral pan‐class I PI3K inhibitor,in Japanese patients with advanced solid tumors

Buparlisib (BKM120) is an oral pan‐phosphatidylinositol 3‐kinase inhibitor, targeting all four isoforms of class I PI3K (α, β, γ and δ). This open‐label Phase I dose‐escalation study was conducted to determine the maximum tolerated dose of continuous daily buparlisib in Japanese patients with advanced solid tumors. Secondary objectives included safety and tolerability, pharmacokinetics, antitumor activity and pharmacodynamic marker changes. Fifteen patients were treated at 25 mg/day (n = 3), 50 mg/day (n = 3) and 100 mg/day (n = 9) dose levels. One dose‐limiting toxicity of Grade 4 abnormal liver function occurred at 100 mg/day. Considering the safety profile and the maximum tolerated dose in the first‐in‐man study of buparlisib in non‐Japanese patients, further dose escalation was stopped and 100 mg/day was declared the recommended dose. The most common treatment‐related adverse events were rash, abnormal hepatic function (including increased transaminase levels), increased blood insulin levels and increased eosinophil count. Hyperglycemia was experienced by two patients, one Grade 1 and one Grade 4, and mood alterations were experienced by three patients, two Grade 1 and one Grade 2. Pharmacokinetic results showed that buparlisib was rapidly absorbed in a dose‐proportional manner. Best overall response was stable disease for six patients, including one unconfirmed partial response. In these Japanese patients with advanced solid tumors, buparlisib had a manageable safety profile, with similar pharmacokinetics to non‐Japanese patients. The recommended dose of 100 mg/day will be used in future studies of buparlisib in Japanese patients.     

Phase I study of single‐agent ribociclib in Japanese patients with advanced solid tumors

The cyclin D‐CDK4/6‐INK4‐Rb pathway is frequently dysregulated in cancers. Ribociclib, an orally available, selective CDK4/6 inhibitor, showed preliminary clinical activity in a phase I study in the USA and Europe for patients with solid tumors and lymphomas. The present study aimed to determine the single‐agent maximum tolerated dose (MTD) and recommended dose for expansion (RDE) in Japanese patients with advanced solid tumors. Ribociclib safety, tolerability, pharmacokinetic profile, and preliminary antitumor activity were also assessed. Japanese patients with solid tumors that had progressed on prior therapies received escalating doses of single‐agent ribociclib on a 3‐weeks‐on/1‐week‐off schedule. Treatment continued until the development of toxicity or disease progression. A dose escalation was planned for patients with esophageal cancer. In the dose‐escalation phase, 4 patients received 400 mg ribociclib and 13 patients received 600 mg ribociclib. Four patients experienced dose‐limiting toxicities, 3 of whom were in the 600 mg group. The RDE was declared to be 600 mg, and the MTD was not determined. The most frequent adverse events were hematologic and gastrointestinal. Four patients achieved stable disease at the 600 mg dose; no patients achieved complete or partial response. All patients discontinued the study, the majority due to disease progression. No patients discontinued due to adverse events. Dose escalation was not pursued due to lack of observed efficacy in esophageal cancer. At the RDE of 600 mg/d on a 3‐weeks‐on/1‐week‐off schedule, ribociclib showed acceptable safety and tolerability profiles in Japanese patients with advanced solid tumors.     

Ribociclib Plus Letrozole in Patients with Hormone Receptor-positive,HER2-negative Advanced Breast Cancer with No Prior Endocrine Therapy: Subgroup Safety Analysis from The Phase 3b CompLEEment-1 Trial

BackgroundThe CDK4/6 inhibitor, ribociclib in combination with endocrine therapy significantly improved progression-free survival in the first line setting in post-menopausal patients with HR+/HER2− advanced breast cancer (ABC) in a pivotal phase 3, placebo-controlled trial (MONALEESA-2) and demonstrated superior overall survival in premenopausal patients with HR+/HER2− ABC (MONALEESA-7). The multinational, phase 3b, CompLEEment-1 trial, which assessed the safety and efficacy of ribociclib plus letrozole in a broader population of patients who have not received prior endocrine therapy for advanced disease, is the largest phase 3 clinical trial to date to evaluate the safety and efficacy of a CDK4/6 inhibitor. We report a subanalysis of data from patients (N = 339) enrolled in the central and south European countries of the SERCE (Southern Europe, RUC, Central Europe) cluster of CompLEEment-1.Patients and methodsMen and women of any menopausal status with HR+/HER2− ABC received once-daily oral ribociclib 600 mg (3-weeks on/1-week-off), plus letrozole 2.5 mg continuously. Men/premenopausal women also received a GnRH-agonist. The primary outcome was the number of patients with adverse events (AEs) over a timeframe of approximately 36 months. Time-to-progression, overall response rate, and clinical benefit rate were also measured.ResultsSafety results in the SERCE subgroup were consistent with those in the pivotal clinical trials of ribociclib in combination with endocrine therapy. Treatment-related AEs leading to dose adjustments/interruption occurred in 63.1% of patients but led to treatment discontinuation in only 10.6%. The most common treatment-related AEs of grade ≥ 3 were neutropenia and transaminase elevations. There were no fatal treatment-related events.ConclusionsThese findings from the SERCE subgroup support the safety and manageable tolerability of ribociclib in a broad range of patients with HR+/HER2− ABC more representative of patients in real-world clinical practice.Key words: CDK4/6 inhibitor, ribociclib, HR+, HER2−, advanced breast cancer, CompLEEment-1 trial     

Phase I study of alpelisib (BYL719), an α‐specific PI3K inhibitor,in Japanese patients with advanced solid tumors

This phase I study aimed to determine tolerability and preliminary efficacy of single‐agent alpelisib (BYL719) in Japanese patients with advanced solid malignancies. The primary objective of the study was to estimate the maximum tolerated dose (MTD) and/or recommended phase II dose (RP2D) of oral alpelisib in patients with advanced solid tumors who had progressed despite standard therapy. The expansion part included patients with PIK3CA mutation/amplification; safety, preliminary efficacy, pharmacokinetic (PK)/pharmacodynamic profile, and food effect on the PK profile of alpelisib at the MTD/RP2D were determined. Oral alpelisib was given as a single agent on a continuous 28‐day treatment cycle once daily. Overall, 33 patients received alpelisib. Dose‐limiting toxicities were observed in 2 patients in the escalation part (at 400 mg/day) and 1 patient in the expansion part (at 350 mg/day). The RP2D of alpelisib was determined as 350 mg/day based on overall safety profile in the dose escalation part and previous data from a Western population; the MTD was not determined. The most common all‐grade treatment‐suspected adverse events were hyperglycemia and maculopapular rash (48.5% each) and diarrhea (45.5%). The PK of alpelisib in the Japanese population was similar to that reported in the Western population. The overall response rate, disease control rate, and median progression‐free survival at 350 mg/day were 3%, 57.6%, and 3.4 months, respectively. Alpelisib as single agent showed a favorable safety profile and encouraging preliminary efficacy in Japanese patients with advanced solid tumors.     

Clinical activity of ASP8273 in Asian patients with non‐small‐cell lung cancer with EGFR activating and T790M mutations

Epidermal growth factor receptor (EGFR)‐activating mutations confer sensitivity to tyrosine kinase inhibitor (TKI) treatment for non‐small‐cell lung cancer (NSCLC). ASP8273 is a highly specific, irreversible, once‐daily, oral, EGFR TKI that inhibits both activating and resistance mutations. This ASP8273 dose‐escalation/dose‐expansion study (NCT02192697) was undertaken in two phases. In phase I, Japanese patients (aged ≥20 years) with NSCLC previously treated with ≥1 EGFR TKI received escalating ASP8273 doses (25‐600 mg) to assess safety/tolerability and to determine the maximum tolerated dose (MTD) and/or the recommended phase II dose (RP2D) by the Bayesian Continual Reassessment Method. In phase II, adult patients with T790M‐positive NSCLC in Japan, Korea, and Taiwan received ASP8273 at RP2D to further assess safety/tolerability and determine antitumor activity, which was evaluated according to Simon's two‐stage design (threshold response = 30%, expected response = 50%, α = 0.05, β = 0.1). Overall, 121 (n = 45 [33W/12M] phase I, n = 76 [48W/28M]) phase 2) patients received ≥1 dose of ASP8273. In phase I, RP2D and MTD were established as 300 and 400 mg, respectively. As 27 of the 63 patients treated with ASP8273 300 mg achieved a clinical response, ASP8273 was determined to have antitumor activity. The overall response rate at week 24 in all patients was 42% (n = 32/76; 95% confidence interval, 30.9‐54.0). Median duration of progression‐free survival was 8.1 months (95% confidence interval, 5.6, upper bound not reached). The most commonly reported treatment‐related adverse event in phase II was diarrhea (57%, n = 43/76). ASP8273 300 mg was generally well tolerated and showed antitumor activity in Asian patients with both EGFR‐activating and T790M mutations.     

Updated results from MONALEESA-2, a phase III trial of first-line ribociclib plus letrozole versus placebo plus letrozole in hormone receptor-positive,HER2-negative advanced breast cancer

BackgroundThe phase III MONALEESA-2 study demonstrated significantly prolonged progression-free survival (PFS) and a manageable toxicity profile for first-line ribociclib plus letrozole versus placebo plus letrozole in patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2–) advanced breast cancer. Here, we report updated efficacy and safety data, together with exploratory biomarker analyses, from the MONALEESA-2 study.Patients and methodsA total of 668 postmenopausal women with HR+, HER2– recurrent/metastatic breast cancer were randomized (1 : 1; stratified by presence/absence of liver and/or lung metastases) to ribociclib (600 mg/day; 3-weeks-on/1-week-off; 28-day treatment cycles) plus letrozole (2.5 mg/day; continuous) or placebo plus letrozole. The primary end point was locally assessed PFS. The key secondary end point was overall survival (OS). Other secondary end points included overall response rate (ORR) and safety. Biomarker analysis was an exploratory end point.ResultsAt the time of the second interim analysis, the median duration of follow-up was 26.4 months. Median PFS was 25.3 months [95% confidence interval (CI) 23.0–30.3] for ribociclib plus letrozole and 16.0 months (95% CI 13.4–18.2) for placebo plus letrozole (hazard ratio 0.568; 95% CI 0.457–0.704; log-rank P = 9.63 × 10⁻⁸). Ribociclib treatment benefit was maintained irrespective of PIK3CA or TP53 mutation status, total Rb, Ki67, or p16 protein expression, and CDKN2A, CCND1, or ESR1 mRNA levels. Ribociclib benefit was more pronounced in patients with wild-type versus altered receptor tyrosine kinase genes. OS data remain immature, with 116 deaths observed; 50 in the ribociclib arm and 66 in the placebo arm (hazard ratio 0.746; 95% CI 0.517–1.078). The ORR was 42.5% versus 28.7% for all patients treated with ribociclib plus letrozole versus placebo plus letrozole, respectively, and 54.5% versus 38.8%, respectively, for patients with measurable disease. Safety results, after a further 11.1 months of follow-up, were comparable with those reported at the first analysis, with no new or unexpected toxicities observed, and no evidence of cumulative toxicity.ConclusionsThe improved efficacy outcomes and manageable tolerability observed with first-line ribociclib plus letrozole are maintained with longer follow-up, relative to letrozole monotherapy.Clinical trials numberNCT01958021     

Time to death in breast cancer patients as an indicator of treatment response

Purpose

Determine the efficacy and safety of first-line ribociclib plus letrozole in elderly patients with HR+, HER2? advanced breast cancer.

Methods

668 postmenopausal women with HR+, HER2? advanced breast cancer and no prior systemic therapy for advanced disease were enrolled in the Phase III MONALEESA-2 trial (NCT01958021); 295 patients were aged ≥ 65 years. Patients were randomized to ribociclib (600 mg/day; 3-weeks-on/1-week-off) plus letrozole (2.5 mg/day) or placebo plus letrozole until disease progression, unacceptable toxicity, death, or treatment discontinuation. The primary endpoint was PFS, which was evaluated in elderly (≥ 65 years) and younger (< 65 years) patients. Secondary endpoints included response rates and safety.

Results

Ribociclib plus letrozole significantly improved PFS vs placebo plus letrozole in elderly (hazard ratio: 0.608; 95% CI 0.394–0.937) and younger patients (hazard ratio: 0.523; 95% CI 0.378–0.723). Overall response rates were numerically higher in the ribociclib vs placebo arm, regardless of age. Ribociclib plus letrozole was well tolerated in elderly patients, with the safety profile similar to the overall study population. Nausea, vomiting, alopecia, and diarrhea were > 10% more frequent in the ribociclib plus letrozole vs placebo plus letrozole arm in both subgroups; most events were grade 1/2. In elderly patients, grade 1/2 anemia and fatigue were > 10% more frequent in the ribociclib plus letrozole vs placebo plus letrozole arm and discontinuation rates were similar in both arms.

Conclusions

Addition of ribociclib to letrozole is a valid therapeutic option for elderly patients with HR+, HER2? advanced breast cancer in the first-line setting.

     

Patritumab plus trastuzumab and paclitaxel in human epidermal growth factor receptor 2‐overexpressing metastatic breast cancer

Human epidermal growth factor receptor 3 (HER3) expression in lung and breast cancers has a negative impact on survival. Patritumab, a human anti‐HER3 mAb, has shown anticancer activity in preclinical models. This study examined the safety and pharmacokinetics of patritumab in combination with trastuzumab and paclitaxel in patients with HER2‐overexpressing metastatic breast cancer. In this open‐label, multicenter, dose‐escalation, phase Ib study, patients received patritumab 9 or 18 mg/kg plus trastuzumab and paclitaxel at known tolerated doses. Safety and tolerability were assessed based on dose‐limiting toxicities and other non‐life threatening adverse events. The pharmacokinetic profile for patritumab was determined based on the target trough level. Clinical efficacy was evaluated based on the overall response rate and progression‐free survival. Six patients received patritumab 9 mg/kg and 12 received 18 mg/kg. The most common adverse events were diarrhea, alopecia, leukopenia, neutropenia, and maculopapular rash. No dose‐limiting toxicities were observed. The target trough serum concentration was achieved in all patients at a dose of 18 mg/kg. Overall response rate was 38.9% and median progression‐free survival was 274 days. In conclusion, patritumab plus trastuzumab and paclitaxel was tolerable and efficacious at both doses. We recommend the dose level of 18 mg/kg for future phase II studies. (Clinical trial registration: JapicCTI‐121772.)     

Ribociclib plus letrozole versus letrozole alone in patients with de novo HR+, HER2− advanced breast cancer in the randomized MONALEESA-2 trial

Purpose

Determine the efficacy and safety of first-line ribociclib plus letrozole in patients with de novo advanced breast cancer.

Methods

Postmenopausal women with HR+ , HER2? advanced breast cancer and no prior systemic therapy for advanced disease were enrolled in the Phase III MONALEESA-2 trial (NCT01958021). Patients were randomized to ribociclib (600 mg/day; 3 weeks-on/1 week-off) plus letrozole (2.5 mg/day; continuous) or placebo plus letrozole until disease progression, unacceptable toxicity, death, or treatment discontinuation. The primary endpoint was investigator-assessed progression-free survival; predefined subgroup analysis evaluated progression-free survival in patients with de novo advanced breast cancer. Secondary endpoints included safety and overall response rate.

Results

Six hundred and sixty-eight patients were enrolled, of whom 227 patients (34%; ribociclib plus letrozole vs placebo plus letrozole arm: n = 114 vs. n = 113) presented with de novo advanced breast cancer. Median progression-free survival was not reached in the ribociclib plus letrozole arm versus 16.4 months in the placebo plus letrozole arm in patients with de novo advanced breast cancer (hazard ratio 0.45, 95% confidence interval 0.27–0.75). The most common Grade 3/4 adverse events were neutropenia and leukopenia; incidence rates were similar to those observed in the full MONALEESA-2 population. Ribociclib dose interruptions and reductions in patients with de novo disease occurred at similar frequencies to the overall study population.

Conclusions

Ribociclib plus letrozole improved progression-free survival vs placebo plus letrozole and was well tolerated in postmenopausal women with HR+, HER2? de novo advanced breast cancer.

     

Phase I/II study of bortezomib‐melphalan‐prednisolone for previously untreated Japanese patients with multiple myeloma

This phase I/II study was conducted to evaluate the safety and efficacy of bortezomib‐melphalan‐prednisolone in Japanese patients with previously untreated multiple myeloma who are ineligible for hematopoietic stem cell transplantation. One hundred and one patients were enrolled, and 99 patients received up to nine 6‐week cycles of bortezomib (0.7/1.0/1.3 mg/m²) on days 1, 4, 8, 11, 22, 25, 29, and 32 in cycles 1–4 and on days 1, 8, 22, and 29 in cycles 5–9, with melphalan (9 mg/m²) and prednisolone (60 mg/m²) on days 1–4 of each cycle. The recommended dose was determined in the phase I portion, and the overall response rate and safety of bortezomib‐melphalan‐prednisolone at the recommended dose were assessed in the phase II portion. The recommended dose of bortezomib was determined to be 1.3 mg/m². Grade 3 or higher non‐hematological adverse events included diarrhea (12%) and peripheral neuropathy (10%); grade 4 hematological adverse events included lymphopenia (41%), neutropenia (30%), and thrombocytopenia (22%). Eleven patients had lung injury associated with bortezomib; two had grade 3 disease, and the other nine had grade 1 or 2 disease. Of the 86 patients treated with 1.3‐mg/m² bortezomib in phases I and II, the median number of treatment cycles was 4.5, and the overall response rate was 70% (95% confidence interval: 59–79%). Bortezomib‐melphalan‐prednisolone with 1.3‐mg/m² bortezomib was considered to be tolerable and effective in Japanese patients with previously untreated multiple myeloma. However, further investigation is needed to refine the administration schedule.     

Phase I study of palbociclib,a cyclin‐dependent kinase 4/6 inhibitor,in Japanese patients

This phase I study in Japanese patients evaluated the safety, pharmacokinetics, and preliminary efficacy of palbociclib, a highly selective and reversible oral cyclin‐dependent kinase 4/6 inhibitor, as monotherapy for solid tumors (part 1) and combined with letrozole as first‐line treatment of postmenopausal patients with estrogen receptor‐positive, human epidermal growth factor receptor 2‐negative advanced breast cancer (part 2). Part 1 evaluated palbociclib 100 and 125 mg once daily (3 weeks on/1 week off; n = 6 each group) to determine the maximum tolerated dose. Part 2 evaluated palbociclib maximum tolerated dose (125 mg) plus letrozole 2.5 mg (n = 6). The most common treatment‐related adverse event was neutropenia (all grades/grade 3/4): 100 mg, 83%/67%; 125 mg, 67%/33%; and palbociclib plus letrozole, 100%/83%. Heavier pretreatment with chemotherapy may have resulted in higher neutropenia rates observed with the 100‐mg dose. Palbociclib exposure was higher with 125 vs 100 mg (mean area under the plasma concentration–time curve over dosing interval [τ]: 1322 vs 547.5 ng·h/mL [single dose], 2838 vs 1276 ng·h/mL [multiple dose]; mean maximum plasma concentration: 104.1 vs 41.4 ng/mL [single dose], 185.5 vs 77.4 ng/mL [multiple dose]). Half‐life was 23–26 h. No drug–drug interactions between palbociclib and letrozole occurred. Four patients had stable disease (≥24 weeks in one patient with rectal cancer [100 mg] and one with esophageal cancer [125 mg]) in part 1; two patients had partial response and two had stable disease (both ≥24 weeks) in part 2. Palbociclib at the 125‐mg dose (schedule 3/1) was tolerated and is the recommended dose for monotherapy and letrozole combination therapy in Japanese patients. The trials are registered with www.ClinicalTrials.gov : A5481010 and NCT01684215.     

Tolerability and efficacy of durvalumab in Japanese patients with advanced solid tumors

Blockade of programmed cell death ligand‐1 with durvalumab has shown efficacy and safety in large, international studies of patients with advanced solid tumors. A phase 1, non‐randomized, open‐label multicenter study was initiated to evaluate durvalumab in a Japanese population. The first part of this study used a standard 3 + 3 dose‐escalation design to determine the optimal dosing schedule of durvalumab. Primary objective was evaluation of safety and tolerability of durvalumab monotherapy. Secondary objectives were to evaluate maximum tolerated dose (MTD), immunogenicity, pharmacokinetics, and efficacy. Twenty‐two patients (median age, 61.5 years; range, 41‐76; 64% male) received durvalumab at doses of 1, 3, or 10 mg/kg every 2 weeks (q2w), 15 mg/kg q3w, or 20 mg/kg q4w. Twenty patients discontinued before completing 12 months of treatment as a result of progressive disease and two due to adverse events (AE). The most common treatment‐related AE (trAE) were rash (18%) and pruritus (14%); two patients had grade ≥3 trAE including one patient each with hyponatremia and hypothyroidism. No patient experienced a dose‐limiting toxicity (DLT) during the DLT evaluation period and the MTD was not identified. There were no AE leading to a fatal outcome during study treatment. Durvalumab showed dose‐proportional pharmacokinetics across the 1‐20 mg/kg dose range; incidence of positive titers for antidrug antibodies was 9%. One patient with lung cancer had a partial response and disease control rate at 12 weeks was 36%. In conclusion, durvalumab at the doses and regimens evaluated was safe and well tolerated in Japanese patients with advanced solid tumors.     

Full population results from the core phase of CompLEEment-1, a phase 3b study of ribociclib plus letrozole as first-line therapy for advanced breast cancer in an expanded population

Purpose

CompLEEment-1 is a phase 3b trial in an expanded patient population with hormone receptor-positive (HR?+), human epidermal growth factor receptor-2–negative (HER2–) advanced breast cancer (ABC), the largest current trial of cyclin-dependent kinase 4 and 6 inhibitors in ABC.

Methods

Patients treated with?≤?1 line of prior chemotherapy and no prior endocrine therapy for ABC received ribociclib 600 mg/day (3-weeks-on/1-week-off) plus letrozole 2.5 mg/day and additionally monthly goserelin/leuprolide in men and pre-/perimenopausal women. Eligibility criteria allowed inclusion of patients with stable CNS metastases and an Eastern Cooperative Oncology Group performance status of 2. Primary objectives were safety and tolerability, and secondary objectives were efficacy and quality of life (QoL).

Results

Overall, 3,246 patients were evaluated (median follow-up 25.4 months). Rates of all-grade and grade?≥?3 treatment-related adverse events (AEs) were 95.2% and 67.5%, respectively. Treatment-related discontinuations due to all grade and grade?≥?3 AEs occurred in 12.9% and 7.3% of patients, respectively. Rates of all-grade AEs of special interest (AESI) were as follows: neutropenia (74.5%), increased alanine aminotransferase (16.2%), increased aspartate aminotransferase (14.1%), and QTcF prolongation (6.7%); corresponding values for grade?≥?3 AESI were 57.2%, 7.7%, 5.7%, and 1.0%, respectively. Median time to progression was 27.1 months (95% confidence interval, 25.7 to not reached). Patient QoL was maintained during treatment.

Conclusion

Safety and efficacy data in this expanded population were consistent with the MONALEESA-2 and MONALEESA-7 trials and support the use of ribociclib plus letrozole in the first-line setting for patients with HR?+?, HER2– ABC.

Trial registration

linicalTrials.gov NCT02941926.

     

Phase‐1 study of abiraterone acetate in chemotherapy‐naïve Japanese patients with castration‐resistant prostate cancer

Persistent androgen synthesis under castration status in adrenal gland, testes and tumor cells is thought to be one of the major causes of development and progression of castration‐resistant prostate cancer (CRPC). Abiraterone acetate (AA), the prodrug of abiraterone, which is an inhibitor of androgen synthesis enzymes, was evaluated for pharmacokinetics, pharmacodynamics, preliminary efficacy and safety in Japanese patients with CRPC in a phase‐1, open‐label and dose‐escalation study. Chemotherapy‐naïve Japanese CRPC patients (N = 27) received one of four AA daily doses (250 mg [n = 9], 500 mg [n = 6], 1000 [1 h premeal] mg [n = 6] and 1000 [2 h postmeal] mg [n = 6]) continuously through 28‐day treatment cycles. In the first cycle, AA monotherapy was given on days 1–7 for pharmacokinetics, and AA plus prednisone (5 mg twice daily) from days 8 to 28. Of 27 patients, 9 continued treatment with AA until the data cut‐off date (18 July 2013). Over the evaluated dose range, plasma abiraterone concentrations increased with dose, with median t_max 2–3 h. At each dose level, mean serum corticosterone concentrations increased, while testosterone and dehydroepiandrosterone sulfate concentrations rapidly decreased following a single AA dose and were further reduced to near the quantification limit on day 8 regardless of the dose. At least 3 patients from each dose‐group experienced ≥50% prostate‐specific antigen reduction, suggesting clinical benefit from AA in Japanese CRPC patients. AA was generally well‐tolerated, and, therefore, the recommended AA dosage regimen in Japanese CRPC patients is 1000 mg oral dose under modified fasting conditions (at least 1 h premeal or 2 h postmeal). This study is registered at ClinicalTrials.gov : NCT01186484.     

Phase I study of highly selective inhibitor of VEGFR tyrosine kinase,tivozanib, in Japanese patients with solid tumors

Tivozanib is a potent and selective inhibitor of vascular endothelial growth factor receptor (VEGFR) tyrosine kinases. A previous clinical trial in the EU and USA indicated that tivozanib at the maximum tolerated dose of 1.5 mg/day showed an antitumor activity in patients with renal cell carcinoma. This Japanese phase I study was designed to determine the recommended phase II dose of tivozanib for Japanese patients; secondary objectives included pharmacokinetic/pharmacodynamic profiles and preliminary efficacy. Daily treatment with tivozanib in a 3‐weeks‐on/1‐week‐off cycle was examined in nine Japanese patients with advanced solid tumors in the 3 + 3 design (Level 1, 1.0 mg; Level 2, 1.5 mg). No dose‐limiting toxicity was observed throughout the study, and the maximum tolerated dose was not reached. The most commonly observed drug‐related adverse events were diarrhea, dysphonia, rash, thyroid stimulating hormone increase, and with severity grade ≥3, hand‐foot skin reaction, hypertension, and proteinuria. Those adverse events were generally well‐manageable and mostly resolved within the tolerability evaluation period. Serum exposure to tivozanib resulted in t_1/2 of more than >60 h. Increase of plasma VEGF and decrease of plasma VEGFR‐1 and VEGFR‐2 were observed 1–3 weeks after tivozanib treatment. Although no complete or partial response was observed, long‐term stable disease continuing more than 170 days was observed in three renal cell carcinoma patients who had failed prior VEGFR inhibitors. In conclusion, 1.5 mg/day of tivozanib in a 3‐weeks‐on/1‐week‐off setting was tolerable in Japanese patients, and was recommended for further clinical trials in the Japanese population. Clinical trial Registration No: JapicCTI‐090854.     

Phase I / II study of brentuximab vedotin in Japanese patients with relapsed or refractory CD30‐positive Hodgkin's lymphoma or systemic anaplastic large‐cell lymphoma

Brentuximab vedotin is an antibody–drug conjugate that selectively delivers the antimicrotubule agent monomethyl auristatin E into CD30‐expressing cells. To assess its safety, pharmacokinetics, and efficacy in Japanese patients with refractory or relapsed CD30‐positive Hodgkin's lymphoma or systemic anaplastic large‐cell lymphoma, we carried out a phase I/II study. Brentuximab vedotin was given i.v. on day 1 of each 21‐day cycle up to 16 cycles. In the phase I part of a dose‐escalation design, three patients per cohort were treated at doses of 1.2 and 1.8 mg/kg. In the phase II part, a dose of 1.8 mg/kg was given to 14 patients (nine with Hodgkin's lymphoma and five with systemic anaplastic large‐cell lymphoma). The median number of treatment cycles was 16 (range, 4–16). In the phase I part, no dose‐limiting toxicity event was observed. In the total population, common adverse events included lymphopenia (80%), neutropenia (65%), leukopenia (65%), and peripheral sensory neuropathy (60%). Grade 3/4 adverse events in more than two patients were lymphopenia (50%) and neutropenia (15%). The pharmacokinetic profile was similar to that observed in the previous studies in the USA. In the phase II part, six patients (67%) with Hodgkin's lymphoma achieved an objective response with 56% of complete response rate, and five patients (100%) with systemic anaplastic large‐cell lymphoma achieved an objective response with 80% of complete response rate. These results show that brentuximab vedotin has an acceptable safety profile and promising antitumor activity in the Japanese population. This trial was registered in JAPIC Clinical Trials Information (JapicCTI‐111650).     

Phase 1 study of capmatinib in MET‐positive solid tumor patients: Dose escalation and expansion of selected cohorts

Capmatinib is an oral, ATP‐competitive, and highly potent, type 1b MET inhibitor. Herein, we report phase 1 dose‐escalation results for capmatinib in advanced MET‐positive solid tumor patients and dose expansion in advanced non‐lung tumors. Capmatinib was well tolerated with a manageable safety profile across all explored doses. Dose‐limiting toxicities (DLT) occurred at 200 mg twice daily (bid), 250 mg bid, and 450 mg bid capsules; however, no DLT were reported at 600 mg bid (capsules). Capmatinib tablets at 400 mg bid had comparable tolerability and exposure to that of 600 mg bid capsules. Maximum tolerated dose was not reached; recommended phase 2 dose was 400 mg bid tablets/600 mg bid capsules; at this dose, C_trough >EC₉₀ (90% inhibition of c‐MET phosphorylation in animal models) is expected to be achieved and maintained. Among the dose‐expansion patients (N = 38), best overall response across all cohorts was stable disease (gastric cancer 22%, hepatocellular carcinoma 46%, other indications 28%); two other indication patients with gene copy number (GCN) ≥6 achieved substantial tumor reduction. Near‐complete immunohistochemically determined phospho‐MET inhibition (H‐score = 2) was shown following capmatinib 450 mg bid capsule in paired biopsies obtained from one advanced colorectal cancer patient. Incidence of high‐level MET GCN (GCN ≥6) and MET‐overexpressing (immunohistochemistry 3+) tumors in the expansion cohorts was 8% and 13%, respectively; no MET mutations were observed. Thus, the recommended phase 2 dose (RP2D) of capmatinib was 600 mg bid capsule/400 mg bid tablet. Capmatinib was well tolerated and showed antitumor activity and acceptable safety profile at the RP2D. (ClinicalTrials.gov Identifier: NCT01324479).     

Efficacy and safety of fulvestrant in postmenopausal patients with hormone receptor-positive advanced breast cancer: a systematic literature review and meta-analysis

Purpose

Evaluate patient-reported outcomes (PROs) for postmenopausal women with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2?) advanced breast cancer treated with first-line ribociclib plus letrozole.

Methods

In the phase III MONALEESA-2 study (NCT01958021), 668 patients were randomized 1:1 to ribociclib (600 mg/day; 3-weeks-on/1-week-off) plus letrozole (2.5 mg/day) or placebo plus letrozole. PROs were assessed using the European Organisation for Research and Treatment of Cancer core quality-of-life (EORTC QLQ-C30) and breast cancer-specific (EORTC QLQ-BR23) questionnaires. Changes from baseline and time to deterioration in health-related quality of life (HRQoL) were analyzed using linear mixed-effect and stratified Cox regression models, respectively. Exploratory analysis of area-under-the-curve for change from baseline in pain score (AUC-pain) was performed.

Results

On-treatment HRQoL scores were consistently maintained from baseline and were similar between arms. A clinically meaningful (>?5 points) reduction in pain score was observed as early as Week 8 and was maintained up to Cycle 15 in the ribociclib arm. A statistically significant increase in mean AUC-pain was also observed in the ribociclib arm. Scores for all other EORTC QLQ-C30 and EORTC QLQ-BR23 domains were maintained from baseline and were similar between arms.

Conclusions

HRQoL was consistently maintained from baseline in postmenopausal women with HR+, HER2? advanced breast cancer receiving ribociclib plus letrozole and was similar to that observed in the placebo plus letrozole arm. Together with the improved clinical efficacy and manageable safety profile, these PRO results provide additional support for the benefit of ribociclib plus letrozole in this patient population.

     

Safety and pharmacokinetics of milademetan,a MDM2 inhibitor,in Japanese patients with solid tumors: A phase I study

Milademetan (DS-3032, RAIN-32) is an orally available mouse double minute 2 (MDM2) antagonist with potential antineoplastic activity owing to increase in p53 activity through interruption of the MDM2-p53 interaction. This phase I, dose-escalating study assessed the safety, tolerability, efficacy, and pharmacokinetics of milademetan in 18 Japanese patients with solid tumors who relapsed after or were refractory to standard therapy. Patients aged ≥ 20 years received oral milademetan once daily (60 mg, n = 3; 90 mg, n = 11; or 120 mg, n = 4) on days 1 to 21 in a 28-day cycle. Dose-limiting toxicities, safety, tolerability, maximum tolerated dose, pharmacokinetics, and recommended dose for phase II were determined. The most frequent treatment-emergent adverse events included nausea (72.2%), decreased appetite (61.1%), platelet count decreased (61.1%), white blood cell count decreased (50.0%), fatigue (50.0%), and anemia (50.0%). Dose-limiting toxicities (three events of platelet count decreased and one nausea) were observed in the 120-mg cohort. The plasma concentrations of milademetan increased in a dose-dependent manner. Stable disease was observed in seven out of 16 patients (43.8%). Milademetan was well tolerated and showed modest antitumor activity in Japanese patients with solid tumors. The recommended dose for phase II was considered to be 90 mg in the once-daily 21/28-day schedule. Future studies would be needed to further evaluate the potential safety, tolerability, and clinical activity of milademetan in patients with solid tumors and lymphomas. The trial was registered with Clinicaltrials.jp: JapicCTI-142693.