Avelumab first-line maintenance plus best supportive care (BSC) vs BSC alone for advanced urothelial carcinoma: JAVELIN Bladder 100 Japanese subgroup analysis.

BACKGROUND: The phase 3 JAVELIN Bladder 100 trial showed significantly prolonged overall survival (OS) with avelumab as first-line (1L) maintenance therapy + best supportive care (BSC) vs BSC alone in patients with advanced urothelial carcinoma (UC) that had not progressed with 1L platinum-containing chemotherapy. Efficacy and safety were assessed in patients enrolled in Japan. METHODS: Patients with locally advanced or metastatic UC that had not progressed with 4-6 cycles of 1L platinum-containing chemotherapy were randomized to avelumab (10 mg/kg intravenously every 2 weeks) + BSC or BSC alone. The primary endpoint was OS, and secondary endpoints included progression-free survival (PFS) and safety. RESULTS: In Japanese patients (n = 73) randomized to avelumab + BSC (n = 36) or BSC alone (n = 37), median OS was 24.7 months (95% CI, 18.2-not estimable) vs 18.7 months (95% CI, 12.8-33.0), respectively (HR, 0.81 [95% CI, 0.41-1.58]), and median PFS was 5.6 months (95% CI, 1.9-9.4) vs 1.9 months (95% CI, 1.9-3.8), respectively (HR, 0.63 [95% CI, 0.36-1.11]). In the avelumab + BSC and BSC-alone arms, grade ≥ 3 treatment-emergent adverse events (AEs) occurred in 50.0% vs 8.1%, including grade ≥ 3 treatment-related AEs in 13.9% vs 0%, respectively. Efficacy and safety results in Japanese patients were generally consistent with findings in the overall trial population. CONCLUSION: Avelumab 1L maintenance treatment showed a favorable benefit-risk balance in Japanese patients, supporting avelumab 1L maintenance as a new standard of care in Japanese patients with advanced UC that has not progressed with 1L platinum-containing chemotherapy. TRIAL REGISTRATION: Clinicaltrials.gov NCT02603432.

Avelumab in Combination with Axitinib as First-Line Treatment in Patients with Advanced Hepatocellular Carcinoma: Results from the Phase 1b VEGF Liver 100 Trial.

INTRODUCTION: Combining an immune checkpoint inhibitor with a targeted antiangiogenic agent may leverage complementary mechanisms of action for the treatment of advanced/metastatic hepatocellular carcinoma (aHCC). Avelumab is a human anti-PD-L1 IgG1 antibody with clinical activity in various tumor types; axitinib is a selective tyrosine kinase inhibitor of vascular endothelial growth factor receptors 1, 2, and 3. We report the final analysis from VEGF Liver 100 (NCT03289533), a phase 1b study evaluating safety and efficacy of avelumab plus axitinib in treatment-naive patients with aHCC. METHODS: Eligible patients had confirmed aHCC, no prior systemic therapy, ≥1 measurable lesion, Eastern Cooperative Oncology Group performance status ≤1, and Child-Pugh class A disease. Patients received avelumab 10 mg/kg intravenously every 2 weeks plus axitinib 5 mg orally twice daily until progression, unacceptable toxicity, or withdrawal. Endpoints included safety and investigator-assessed objective response per Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 and modified RECIST (mRECIST) for HCC. RESULTS: Twenty-two Japanese patients were enrolled and treated with avelumab plus axitinib. The minimum follow-up was 18 months as of October 25, 2019 (data cutoff). Grade 3 treatment-related adverse events (TRAEs) occurred in 16 patients (72.7%); the most common (≥3 patients) were hypertension (n = 11 [50.0%]), palmar-plantar erythrodysesthesia syndrome (n = 5 [22.7%]), and decreased appetite (n = 3 [13.6%]). No grade 4 TRAEs or treatment-related deaths occurred. Ten patients (45.5%) had an immune-related AE (irAE) of any grade; 3 patients (13.6%) had an infusion-related reaction (IRR) of any grade, and no grade ≥3 irAE and IRR were observed. The objective response rate was 13.6% (95% CI: 2.9-34.9%) per RECIST 1.1 and 31.8% (95% CI: 13.9-54.9%) per mRECIST for HCC. CONCLUSION: Treatment with avelumab plus axitinib was associated with a manageable toxicity profile and showed antitumor activity in patients with aHCC.

Evaluation of the Association of Polymorphisms With Palbociclib-Induced Neutropenia: Pharmacogenetic Analysis of PALOMA-2/-3.

BACKGROUND: The most frequently reported treatment-related adverse event in clinical trials with the cyclin-dependent kinase 4/6 (CDK4/6) inhibitor palbociclib is neutropenia. Allelic variants in ABCB1 and ERCC1 might be associated with early occurrence (i.e., end of week 2 treatment) of grade 3/4 neutropenia. Pharmacogenetic analyses were performed to uncover associations between single nucleotide polymorphisms (SNPs) in these genes, patient baseline characteristics, and early occurrence of grade 3/4 neutropenia. MATERIALS AND METHODS: ABCB1 (rs1045642, rs1128503) and ERCC1 (rs3212986, rs11615) were analyzed in germline DNA from palbociclib-treated patients from PALOMA-2 (n = 584) and PALOMA-3 (n = 442). SNP, race, and cycle 1 day 15 (C1D15) absolute neutrophil count (ANC) data were available for 652 patients. Univariate and multivariable analyses evaluated associations between SNPs, patient baseline characteristics, and early occurrence of grade 3/4 neutropenia. Analyses were stratified by Asian (n = 122) and non-Asian (n = 530) ethnicity. Median progression-free survival (mPFS) was estimated using the Kaplan-Meier method. The effect of genetic variants on palbociclib pharmacokinetics was analyzed. RESULTS: ABCB1 and ERCC1_rs11615 SNP frequencies differed between Asian and non-Asian patients. Multivariable analysis showed that low baseline ANC was a strong independent risk factor for C1D15 grade 3/4 neutropenia regardless of race (Asians: odds ratio [OR], 6.033, 95% confidence interval [CI], 2.615-13.922, p < .0001; Non-Asians: OR, 6.884, 95% CI, 4.138-11.451, p < .0001). ABCB1_rs1128503 (C/C vs. T/T: OR, 0.57, 95% CI, 0.311-1.047, p = .070) and ERCC1_rs11615 (A/A vs. G/G: OR, 1.75, 95% CI, 0.901-3.397, p = .098) were potential independent risk factors for C1D15 grade 3/4 neutropenia in non-Asian patients. Palbociclib mPFS was consistent across genetic variants; exposure was not associated with ABCB1 genotype. CONCLUSION: This is the first comprehensive assessment of pharmacogenetic data in relationship to exposure to a CDK4/6 inhibitor. Pharmacogenetic testing may inform about potentially increased likelihood of patients developing severe neutropenia (NCT01740427, NCT01942135). IMPLICATIONS FOR PRACTICE: Palbociclib plus endocrine therapy improves hormone receptor-positive/human epidermal growth factor receptor 2-negative advanced breast cancer outcomes, but is commonly associated with neutropenia. Genetic variants in ABCB1 may influence palbociclib exposure, and in ERCC1 are associated with chemotherapy-induced severe neutropenia. Here, the associations of single nucleotide polymorphisms in these genes and baseline characteristics with neutropenia were assessed. Low baseline absolute neutrophil count was a strong risk factor (p < .0001) for grade 3/4 neutropenia. There was a trend indicating that ABCB1_rs1128503 and ERCC1_rs11615 were potential risk factors (p < .10) for grade 3/4 neutropenia in non-Asian patients. Pharmacogenetic testing could inform clinicians about the likelihood of severe neutropenia with palbociclib.

Analysis of subsequent therapy in Japanese patients with hormone receptor‒positive/human epidermal growth factor receptor 2‒negative advanced breast cancer who received palbociclib plus endocrine therapy in PALOMA-2 and -3.

BACKGROUND: In the double-blind, phase 3 PALOMA-2 and PALOMA-3 studies, palbociclib plus endocrine therapy (ET) demonstrated significant improvement in progression-free survival versus placebo plus ET in patients with hormone receptor‒positive/human epidermal growth factor receptor 2‒negative advanced breast cancer. This analysis assessed subsequent treatment patterns after palbociclib therapy in Japanese patients enrolled in the PALOMA-2 and PALOMA-3 studies. METHODS: PALOMA-2 included postmenopausal women who had not received prior systemic therapy for advanced disease. PALOMA-3 included pre- or postmenopausal women who had progressed on previous ET. Types of subsequent therapy were assessed, and treatment durations of subsequent therapy were estimated using the Kaplan-Meier method. RESULTS: Japanese patients were enrolled in PALOMA-2 (n = 46) and PALOMA-3 (n = 35). In both studies, the most common first subsequent therapy was ET (PALOMA-2, 77% in the palbociclib group and 75% in the placebo group; PALOMA-3, 55% and 43%, respectively), followed by chemotherapy (PALOMA-2, 18% and 8%; PALOMA-3, 32% and 57%). The median (95% CI) duration of first subsequent therapy was 6.4 (2.3‒13.9) months with palbociclib plus letrozole and 6.7 (2.8‒13.0) months with placebo plus letrozole in PALOMA-2 and 3.8 (2.4‒5.7) months with palbociclib plus fulvestrant and 9.7 (1.0‒not estimable) months with placebo plus fulvestrant in PALOMA-3. CONCLUSIONS: The types of first subsequent therapy received by Japanese patients in the palbociclib plus ET and placebo plus ET groups were similar. Further evaluation of subsequent therapy data in the real-world setting is warranted considering the small sample size of this analysis.

Palbociclib-letrozole as first-line treatment for advanced breast cancer: Updated results from a Japanese phase 2 study.

Palbociclib is a highly selective, reversible, oral inhibitor of cyclin-dependent kinases 4 and 6 that is approved to treat hormone receptor-positive/human epidermal growth factor receptor 2-negative advanced breast cancer. An open-label, single-arm, Japanese phase 2 study was conducted to investigate the efficacy and safety of palbociclib plus letrozole as first-line treatment in 42 postmenopausal patients with estrogen receptor-positive/human epidermal growth factor receptor 2-negative advanced breast cancer. The probability of progression-free survival originally reported at 1 year was 75.0% (90% confidence interval, 61.3-84.4), but median progression-free survival was not attained at the primary analysis. In this report, updated efficacy and safety results with a longer follow-up period are presented. The median duration of treatment in the updated analysis was 33.0 months (range, 1.8-49.2). The probability of progression-free survival at 1 year was 75.6% (90% confidence interval, 62.4-84.7). Median progression-free survival was 35.7 months (95% confidence interval, 21.7-46.7). Objective response rate and disease control rate were 47.6% (95% confidence interval, 32.0-63.6) and 85.7% (95% confidence interval, 71.5-94.6), respectively. Common treatment-related adverse events (all grades; grade 3/4) were neutropenia (100%; 93%), leukopenia (83%; 60%), and stomatitis (76%; 0%). Treatment-related febrile neutropenia was reported in one patient. In general, no clinically meaningful deterioration in health-related quality of life was observed. Palbociclib plus letrozole remained effective and tolerable in Japanese postmenopausal patients with estrogen receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer in this updated analysis.

Avelumab plus axitinib vs sunitinib for advanced renal cell carcinoma: Japanese subgroup analysis from JAVELIN Renal 101.

The phase 3 JAVELIN Renal 101 trial of avelumab + axitinib vs sunitinib in patients with treatment-naive advanced renal cell carcinoma (RCC) demonstrated significantly improved progression-free survival (PFS) and higher objective response rate (ORR) with the combination vs sunitinib. Japanese patients enrolled in the study (N = 67) were randomized to receive avelumab + axitinib (N = 33) or sunitinib (N = 34); 67% vs 59% had PD-L1+ tumors (≥1% of immune cells) and 6%/64%/27% vs 6%/82%/12% had International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) favorable/intermediate/poor risk status. In patients who received avelumab + axitinib vs sunitinib, median PFS (95% confidence interval [CI]) was not estimable (8.1 months, not estimable) vs 11.2 months (1.6 months, not estimable) (hazard ratio [HR], 0.49; 95% CI, 0.152, 1.563) in patients with PD-L1+ tumors and 16.6 months (8.1 months, not estimable) vs 11.2 months (4.2 months, not estimable) (HR, 0.66; 95% CI, 0.296, 1.464) in patients irrespective of PD-L1 expression. Median overall survival (OS) has not been reached in either arm in patients with PD-L1+ tumors and irrespective of PD-L1 expression. ORR (95% CI) was 60.6% (42.1%, 77.1%) vs 17.6% (6.8%, 34.5%) in patients irrespective of PD-L1 expression. Common treatment-emergent adverse events (all grade; grade ≥3) in each arm were hand-foot syndrome (64%; 9% vs 71%; 9%), hypertension (55%; 30% vs 44%; 18%), hypothyroidism (55%; 0% vs 24%; 0%), dysgeusia (21%; 0% vs 56%; 0%) and platelet count decreased (3%; 0% vs 65%; 32%). Avelumab + axitinib was efficacious and tolerable in treatment-naive Japanese patients with advanced RCC, which is consistent with results in the overall population.

Correction to: Neutropenia management with palbociclib in Japanese patients with advanced breast cancer.

The correct name of the last author should be "Masakazu Toi", and not ''Masakuzu Toi" as given in the original publication of the article.

Neutropenia management with palbociclib in Japanese patients with advanced breast cancer.

BACKGROUND: The cyclin-dependent kinase 4/6 (CDK4/6) inhibitor palbociclib, in combination with endocrine therapy (ET), significantly prolonged progression-free survival in women with hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer (HR+/HER2- ABC) in PALOMA-2 and PALOMA-3. Neutropenia and palbociclib dose reductions/interruptions occurred more frequently in the Japanese versus overall populations. We evaluated neutropenia patterns, palbociclib dose management, and clinical responses after dose reduction in Japanese patients in PALOMA-2 and PALOMA-3 and a single-arm Japanese phase 2 study. METHODS: PALOMA-2 and the Japanese phase 2 study enrolled postmenopausal women with estrogen receptor-positive, HER2- ABC who had not received prior systemic therapy for advanced disease; PALOMA-3 enrolled women with HR+/HER2- ABC, regardless of menopausal status, whose disease had progressed after prior ET. Palbociclib (125 mg/day) was administered 3 weeks on/1 week off. Dose reduction/interruption, cycle delay, tumor response, and laboratory-assessed neutropenia were analyzed in Japanese patients who received palbociclib. RESULTS: A total of 101 Japanese patients received palbociclib + ET. Among Japanese patients in the 3 studies, the frequency of all-grade/grade 3/grade 4 neutropenia was 94%/53%/34%, 100%/69%/21%, and 100%/67%/26%, respectively. Twenty (63%), 28 (67%), and 15 (56%) patients required palbociclib dose reduction. Dose interruption or reduction did not affect palbociclib treatment duration, and durable tumor response was observed despite dose reduction. CONCLUSION: Neutropenia was manageable with dose modifications, without affecting palbociclib treatment duration or efficacy. TRIAL REGISTRATION: Pfizer (NCT01740427, NCT01684215, NCT01942135).

Patients with metastatic renal cell carcinoma who benefit from axitinib dose titration: analysis from a randomised, double-blind phase II study.

BACKGROUND: A prospective, randomised phase II study demonstrated clinical benefit of axitinib dose titration in a subset of treatment-naïve patients treated with axitinib for metastatic renal cell carcinoma. This analysis evaluated patient baseline characteristics that may impact overall survival (OS) with axitinib dose titration. METHODS: Following a 4-week lead-in period during which all patients received axitinib 5 mg twice-daily (bid); patients meeting the predefined randomisation criteria were randomly assigned to receive axitinib 5 mg bid plus either axitinib or placebo titration. In exploratory analyses, patients were grouped into those who achieved OS ≥24 versus < 24 months, and compared their baseline characteristics with Fisher's exact test or Cochran-Armitage trend exact test, with a 5% significance level. Potential predictive baseline characteristics associated with effect of axitinib dose titration on OS were investigated using a Cox proportional hazard model. RESULTS: Overall, 112 patients were randomised. Three of 56 patients receiving axitinib titration were censored; of the remaining 53, 33 (62%) achieved OS ≥24 months versus 20 (38%) with OS < 24 months. Patients with OS ≥24 vs. < 24 months, respectively, had significantly fewer metastatic sites (≤2 metastases: 52% vs. 10%; ≥3 metastases: 48% vs. 90%), fewer lymph node (45% vs. 75%) or liver (15% vs. 45%) metastases, higher haemoglobin level (i.e., ≥ lower limit of normal: 67% vs. 25%) at baseline, lower neutrophil (≤ upper limit of normal, 97% vs. 75%) and platelet (≤ upper limit of normal, 82% vs. 50%) levels at baseline and ≥ 1 year between histopathological diagnosis and treatment (64% vs. 15%). The primary reason for treatment discontinuation in both OS groups was disease progression. The frequency of toxicity-related discontinuation was comparable between the 2 groups, indicating that it was not a factor for a shorter OS. The multivariate analysis showed that ≥1 year from histopathological diagnosis to treatment and baseline haemoglobin level equal or greater than lower limit of normal were significant covariates associated with favourable OS in patients receiving axitinib titration. CONCLUSIONS: The current analyses identified potentially predictive factors that could help selecting patients who may benefit from axitinib dose titration. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT00835978. Registered prospectively, February 4, 2009.

Palbociclib in combination with fulvestrant in patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer: PALOMA-3 subgroup analysis of Japanese patients.

BACKGROUND: In the double-blind, phase 3 PALOMA-3 study, palbociclib-fulvestrant significantly prolonged progression-free survival versus placebo-fulvestrant in patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (MBC) whose disease had progressed on prior endocrine therapy. The present study evaluated the efficacy, safety, and pharmacokinetics of palbociclib plus fulvestrant in Japanese patients enrolled in PALOMA-3. METHODS: Pre/peri/postmenopausal women with HR+/HER2- MBC were randomized 2:1 to fulvestrant (500 mg) and either palbociclib (125 mg/day; 3 weeks on/1 week off; n = 347) or placebo (n = 174). Prespecified exploratory analyses compared the efficacy (data cutoff: October 23, 2015), safety, and pharmacokinetics (data cutoff: December 5, 2014) in Japanese women versus the overall population. RESULTS: A total of 35 Japanese women were randomized to palbociclib-fulvestrant (n = 27) or placebo-fulvestrant (n = 8). Median progression-free survival was 13.6 months (95% CI, 7.5-not estimable) in the Japanese palbociclib-fulvestrant group and 11.2 months (95% CI, 5.6-not estimable) in the placebo-fulvestrant group. The most common adverse event (AE) in Japanese patients was neutropenia (all grades, 93%); no discontinuations were due to an AE. Geometric mean trough concentration values (within-subject mean steady state) for palbociclib were similar for Japanese Asian (excluding Japanese), and non-Asian patients (84.4 ng/mL, 86.3 ng/mL, and 74.8 ng/mL, respectively). CONCLUSION(S): The results for the overall population and Japanese patients in PALOMA-3 suggest that palbociclib plus fulvestrant was effective and well tolerated in Japanese patients with HR+/HER2‒ MBC whose disease had progressed on prior endocrine therapy (Pfizer; NCT01942135).

Palbociclib in combination with letrozole in patients with estrogen receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer: PALOMA-2 subgroup analysis of Japanese patients.

BACKGROUND: In PALOMA-2, palbociclib-letrozole significantly improved progression-free survival (PFS) vs placebo-letrozole in women with estrogen receptor-positive, human epidermal growth factor receptor 2-negative (ER+/HER2-) advanced breast cancer (ABC) in the first-line setting. We evaluated the efficacy, safety, and pharmacokinetics of palbociclib in Japanese women in PALOMA-2. METHODS: In this phase 3 study, 666 postmenopausal women with ER+/HER2- ABC were randomized 2:1 to palbociclib (125 mg/day [3 weeks on/1 week off]) plus letrozole (2.5 mg daily) or placebo plus letrozole. A prespecified, exploratory, subgroup analysis of Japanese patients (n = 46) was conducted to compare results with those of the overall population. RESULTS: At the February 26, 2016 cutoff, median PFS among the 46 Japanese patients was 22.2 months (95%CI, 13.6‒not estimable) with palbociclib-letrozole vs 13.8 months (5.6‒22.2) with placebo-letrozole (hazard ratio, 0.59 [95%CI, 0.26-1.34]). The most common adverse events (AEs) were hematologic and more frequent among Japanese patients than the overall population (neutropenia: 93.8% [87.5% grade 3/4] vs 79.5% [66.4%]; leukopenia: 62.5% [43.8%] vs 39.0% [24.8%]); no Japanese patients had febrile neutropenia. Palbociclib dose reductions due to toxicity (mainly neutropenia) were more common in Japanese patients (62.5% vs 36.0%); few permanently discontinued due to AEs. Although mean palbociclib trough concentration was higher in Japanese patients vs non-Asians (95.4 vs 61.7 ng/mL), the range of individual values of the Japanese patients was within that of non-Asians. CONCLUSIONS: These results from PALOMA-2 suggest that palbociclib-letrozole merits consideration as a first-line treatment option for postmenopausal Japanese patients with ER+/HER2‒ ABC. ClinicalTrials.gov: NCT01740427.

Regional Differences in Efficacy, Safety, and Biomarkers for Second-Line Axitinib in Patients with Advanced Hepatocellular Carcinoma: From a Randomized Phase II Study.

BACKGROUND: An unmet need exists for treatment of patients with advanced hepatocellular carcinoma (HCC) who progress on or are intolerant to sorafenib. A global randomized phase II trial (ClinicalTrial.gov No. NCT01210495) of axitinib, a vascular endothelial growth factor receptor 1-3 inhibitor, in combination with best supportive care (BSC) did not prolong overall survival (OS) over placebo/BSC, but showed improved progression-free survival in some patients. Subgroup analyses were conducted to identify potential predictive/prognostic factors. METHODS: The data from this phase II study were analyzed for the efficacy and safety of axitinib/BSC in patients from Asia versus non-Asia versus Asian subgroups (Japan, Korea, or mainland China/Hong Kong/Taiwan) and predictive/prognostic values of baseline microRNAs and serum soluble proteins, using the Cox proportional hazards model. RESULTS: Of 202 patients, 78 were from non-Asia and 124 from Asia (37 Japanese, 36 Korean, and 51 Chinese). No significant differences in OS were found between axitinib/BSC and placebo/BSC in non-Asians, Asians, or Asian subgroups. However, in an exploratory analysis, axitinib/BSC showed favorable OS in Asians, especially Japanese, when patients intolerant to prior antiangiogenic therapy were excluded from the data set. Axitinib/BSC was well tolerated by non-Asians and Asians alike. The presence of 4 circulating microRNAs, including miR-5684 and miR-1224-5p, or a level lower than or equal to the median protein level of stromal cell-derived factor 1 at baseline was significantly associated with longer OS in axitinib/BSC-treated Asians or non-Asians. CONCLUSIONS: Axitinib/BSC did not prolong survival over placebo/BSC in non-Asians, Asians, or Asian subgroups, but favorable OS with axitinib/BSC was observed in a subset of Japanese patients. A patient population that excludes sorafenib-intolerant patients might potentially be more suitable for clinical trials of new agents in advanced HCC. Since these results are very preliminary, further investigation is warranted. The potential predictive/prognostic value of several baseline microRNAs and soluble proteins identified in this study would require validation in prospective studies on a large cohort of patients.

Palbociclib in combination with letrozole as first-line treatment for advanced breast cancer: A Japanese phase II study.

This single-arm, open-label, phase II study in 42 Japanese postmenopausal patients with estrogen receptor-positive/human epidermal growth factor receptor 2-negative (ER+/HER2-) advanced breast cancer evaluated the efficacy, safety, and pharmacokinetics of first-line palbociclib (125 mg once daily, 3 weeks on/1 week off) coadministered with letrozole (2.5 mg once daily). Primary endpoint of investigator-assessed 1-year progression-free survival (PFS) probability was 75.0% (90% CI, 61.3%-84.4%), far surpassing the 40% lower limit of the 90% CI supporting efficacy. Median duration of treatment was 438 days. Among secondary efficacy measures, median PFS was not reached (95% CI, 16.7: not estimable), 17/42 patients (40.5%) had an objective response, 36/42 (85.7%) maintained disease control, and 27/42 (64.3%) remained in follow-up. Median overall survival was not reached, and 1-year survival probability was 92.9% (95% CI, 79.5%-97.6%). Results of intensive pharmacokinetics in a subset of 6 patients showed palbociclib steady-state mean area under the plasma concentration-time curve over the dosing interval [τ] and mean maximum plasma concentration were 1979 ng·h/mL and 124.7 ng/mL, respectively. For day 15 plasma samples from cycles 1 and 2, geometric mean of the within-patient mean trough concentration was 90.1 ng/mL. The most common treatment-related adverse events were neutropenia (100%) and stomatitis (73.8%). There was 1 case of treatment-related febrile neutropenia. Toxicities were generally tolerated and manageable by dose modifications and/or medical care. Efficacy and safety of first-line palbociclib plus letrozole therapy is supported in Japanese postmenopausal patients with treatment-naive ER+/HER2- advanced breast cancer.

Axitinib in metastatic renal cell carcinoma: beyond the second-line setting.

Treatment options for advanced and metastatic renal cell carcinoma have advanced considerably in the past decade with the approval of several targeted agents, including axitinib. Axitinib is a potent and selective inhibitor of VEGFRs 1-3, and is well established as second-line treatment. This article summarizes factors to be considered when administering axitinib, such as individualized dose titration and axitinib-associated adverse events, in order to retain patients longer on treatment, which would likely lead to improved efficacy outcomes. In addition, potential clinical perspectives for axitinib beyond the second-line setting, including its role in the first-line setting, sequential therapy, neoadjuvant and adjuvant therapies, and combination therapy with immunotherapy, in particular, immune checkpoint inhibitors, are discussed.

Overall survival of first-line axitinib in metastatic renal cell carcinoma: Japanese subgroup analysis from phase II study.

Subgroup analyses of a randomized global phase II study of axitinib showed objective response rate of 66% and median progression-free survival of 27.6 months in treatment-naïve Japanese patients with metastatic renal cell carcinoma (RCC). This analysis evaluated overall survival (OS) and safety in 44 Japanese patients and compared the results with 169 non-Japanese patients. In addition, baseline characteristics for predictive factors that may influence OS in first-line metastatic RCC were explored in all patients using a Cox proportional hazard model. With median follow-up of 33 months, fewer than half (16 of 44) of the Japanese patients had died and median OS was not reached (95% confidence interval [CI], 38.8 months-not estimable), whereas 107 of 169 (63%) non-Japanese patients had died and median OS was 33.9 months (95% CI, 28.9-42.7). Estimated 1-year, 2-year and 3-year survival probability (95% CI) was 86.4% (76.2-96.5), 75.0% (62.2-87.8) and 68.2% (54.4-81.9), respectively, in Japanese patients, and was higher than that in non-Japanese patients (75.1% [68.4-81.8], 62.1% [54.5-69.7] and 47.2% [39.3-55.1], respectively). The updated safety analysis did not reveal any new adverse events of concern among Japanese or non-Japanese patients. The multivariate analysis identified that lower baseline Eastern Cooperative Oncology Group performance status, lower baseline tumor burden, and longer time from histopathological diagnosis to treatment were significant positive predictors of OS. The current analysis confirmed the clinical activity of axitinib in treatment-naïve Japanese patients with metastatic RCC, with an acceptable toxicity profile.

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.

Efficacy and safety of axitinib in combination with gemcitabine in advanced pancreatic cancer: subgroup analyses by region, including Japan, from the global randomized Phase III trial.

OBJECTIVE: Axitinib is a potent and selective inhibitor of vascular endothelial growth factor receptors 1-3. This analysis compared efficacy and safety of axitinib plus gemcitabine in patients with advanced pancreatic cancer from Japan, North America and the European Union, enrolled in a randomized Phase III study. METHODS: Patients (n = 632), stratified by disease extent, were randomly assigned (1:1) to receive axitinib/gemcitabine or placebo/gemcitabine. Axitinib was administered at a starting dose of 5 mg orally twice daily and gemcitabine at 1000 mg/m(2) once weekly for 3 weeks in 4 week cycles. Primary endpoint was overall survival. RESULTS: Among Japanese patients, median overall survival was not estimable (95% confidence interval, 7.4 months-not estimable) with axitinib/gemcitabine (n = 58) and 9.9 months (95% confidence interval, 7.4-10.5) with placebo/gemcitabine (n = 56) (hazard ratio 1.093 [95% confidence interval, 0.525-2.274]). Median survival follow-up (range) was 5.1 months (0.02-12.3) with axitinib/gemcitabine vs. 5.4 months (1.8-10.5) with placebo/gemcitabine. Similarly, no difference was detected in overall survival between axitinib/gemcitabine and placebo/gemcitabine in patients from North America or the European Union. Common adverse events with axitinib/gemcitabine in Japanese patients were fatigue, anorexia, dysphonia, nausea and decreased platelet count. Axitinib safety profile was generally similar in patients from the three regions, although there were differences in incidence of some adverse events. An exploratory analysis did not show any correlation between axitinib/gemcitabine-related hypertension and overall survival. CONCLUSIONS: Axitinib/gemcitabine, while tolerated, did not provide survival benefit over gemcitabine alone in patients with advanced pancreatic cancer from Japan or other regions.

Axitinib plasma pharmacokinetics and ethnic differences.

Axitinib, a potent and selective tyrosine kinase inhibitor of vascular endothelial growth factor receptors 1, 2, and 3, showed improved progression-free survival over sorafenib in patients previously treated for advanced renal cell carcinoma in the AXIS trial. Although a few studies had established the efficacy and safety of axitinib in Asian patients, additional evaluation was necessary to obtain regulatory approval in several Asian countries, especially in light of ethnic differences that are known to exist in genetic polymorphisms for metabolizing enzymes such as cytochrome P450 (CYP) 3A5, CYP2C19 and uridine diphosphate glucuronosyltransferase (UGT) 1A1, which are involved in axitinib metabolism. Axitinib plasma pharmacokinetics following single or multiple administration of oral axitinib in Asian (Japanese or Chinese) healthy subjects as well as Asian patients with advanced solid tumors was compared with that obtained in Caucasians. Upon review, the data demonstrated that axitinib can be characterized as not sensitive to ethnic factors based on its pharmacokinetic and pharmacodynamic properties. Axitinib exhibited similar pharmacokinetics in Asian and non-Asian subjects. A pooled population pharmacokinetic analysis indicated lack of a clinically meaningful effect of ethnicity on axitinib disposition. Therefore, dose adjustment for axitinib on the basis of ethnicity is not currently warranted.

Overall survival and final efficacy and safety results from a Japanese phase II study of axitinib in cytokine-refractory metastatic renal cell carcinoma.

In an open-label, multicenter phase II study of Japanese patients with cytokine-refractory metastatic renal cell carcinoma, axitinib showed substantial antitumor activity with an acceptable safety profile. Here, we report overall survival and updated efficacy and safety results. Sixty-four Japanese patients with metastatic renal cell carcinoma following prior therapy with cytokines were treated with axitinib at a starting dose of 5 mg b.i.d. Following median treatment duration of 14.2 months, median overall survival was 37.3 months (95% CI, 28.6-49.9). The objective response rate, the primary endpoint of the study, was 51.6% (95% CI, 38.7-64.2); the median duration of response, 11.1 months (95% CI, 8.2-13.7); and the median progression-free survival was 11.0 months (95% CI, 9.2-12.0), assessed by the independent review committee. Common treatment-related all-grade adverse events were hypertension (88%), hand-foot syndrome (75%), diarrhea (66%), proteinuria (63%), fatigue (55%) and dysphonia (53%). In an exploratory analysis, median overall survival was found to be significantly longer in patients who had greater decreases in plasma levels of soluble vascular endothelial growth factor receptor-2 during the first cycle of treatment. In conclusion, the present study showed axitinib to be effective, and toxicities with long-term treatment were generally controllable with axitinib dose modification and/or standard medications in these Japanese patients. Some frequently reported adverse events warrant close monitoring and management. Changes in the plasma levels of soluble vascular endothelial growth factor receptor-2 may be used as a prognostic factor for overall survival in metastatic renal cell carcinoma following axitinib treatment. This study is registered at ClinicalTrial.gov (identifier NCT00569946).

Management of axitinib (AG-013736)-induced fatigue and thyroid dysfunction, and predictive biomarkers of axitinib exposure: results from phase I studies in Japanese patients.

BACKGROUND: Axitinib is an oral, potent and selective inhibitor of vascular endothelial growth factor receptors (VEGFRs) 1, 2 and 3. We report on data obtained from 18 Japanese patients with advanced solid tumors in two phase I trials that evaluated the safety, pharmacokinetics and antitumor activity of axitinib and also examined potential biomarkers. METHODS: Six patients received a single 5-mg dose of axitinib followed by 5 mg twice daily (BID), and an additional six patients received axitinib 5 mg BID only. Another six patients received axitinib at 5-mg, 7-mg and 10-mg single doses followed by 5 mg BID. RESULTS: Plasma pharmacokinetics following single doses of axitinib was generally linear. Common treatment-related adverse events were fatigue (83%), anorexia (72%), diarrhea (67%), hand-foot syndrome (67%) and hypertension (61%). Sixteen patients (89%) experienced thyroid-stimulating hormone (TSH) elevation. Grade 3/4 toxicities included hypertension (33%) and fatigue (28%). No grade 3/4 fatigue occurred in patients who started thyroid hormone replacement therapy when TSH was elevated. Thyroglobulin elevation was observed in all patients who continued treatment with axitinib for ≥3 months. Abnormal TSH correlated with exposure to axitinib (r = 0.72). Decrease in soluble (s) VEGFR-2 levels significantly correlated with exposure to axitinib (r = -0.94). Axitinib showed antitumor activity across multiple tumor types. CONCLUSIONS: Axitinib-related thyroid dysfunction could be due to a direct effect on the thyroid gland. Grade 3/4 fatigue and hypothyroidism appear to be controllable with use of thyroid hormone replacement therapy. sVEGFR-2 and TSH may act as biomarkers of axitinib plasma exposure.