Capivasertib and fulvestrant for patients with HR-positive/HER2-negative advanced breast cancer: analysis of the subgroup of patients from Japan in the phase 3 CAPItello-291 trial.

BACKGROUND: In CAPItello-291, capivasertib-fulvestrant significantly improved progression-free survival (PFS) versus placebo-fulvestrant in the overall and PIK3CA/AKT1/PTEN-altered population with hormone receptor-positive (HR-positive)/human epidermal growth factor receptor 2-negative (HER2-negative) advanced breast cancer. Capivasertib-fulvestrant is approved in Japan for the treatment of patients with one or more tumor biomarker alterations (PIK3CA, AKT1 or PTEN). Here, we report outcomes in the CAPItello-291 subgroup of patients from Japan. METHODS: Adults with HR-positive/HER2-negative advanced breast cancer whose disease had relapsed or progressed during or after treatment with an aromatase inhibitor, with or without previous cyclin-dependent kinase 4/6 (CDK4/6) inhibitor therapy, were randomly assigned (1:1 ratio) to receive capivasertib or placebo, plus fulvestrant. The dual primary endpoint was investigator-assessed PFS in the overall and PIK3CA/AKT1/PTEN-altered population. Safety was a secondary endpoint. RESULTS: Of 708 patients randomized in CAPItello-291, 78 were from Japan (37 randomized to capivasertib-fulvestrant and 41 to placebo-fulvestrant). In the Japan subgroup, PFS numerically favored the capivasertib-fulvestrant arm (hazard ratio 0.73; 95% CI 0.40-1.28), consistent with the analysis of PFS in the global population. Similarly, in the Japan subgroup of patients with PIK3CA/AKT1/PTEN-altered tumors, PFS favored the capivasertib-fulvestrant arm (hazard ratio 0.65; 95% CI 0.29-1.39), consistent with the global population. The adverse event profile of capivasertib-fulvestrant in the Japan subgroup was broadly similar to that in the global population; no new safety concerns were identified. CONCLUSION: Outcomes in the Japan subgroup were broadly similar to those of the global population, supporting the clinical benefit of capivasertib-fulvestrant in treating HR-positive/HER2-negative advanced breast cancer that has progressed on, or after, an endocrine-based regimen.

Systemic immunity markers are associated with clinical outcomes of atezolizumab treatment in patients with triple-negative advanced breast cancer: a retrospective multicenter observational study.

Immune checkpoint inhibitors (ICI) are reportedly efficacious against triple-negative breast cancer (TNBC) and are now recommended as first-line therapy. Systemic immunity markers, the absolute lymphocyte count (ALC) and the neutrophil-to-lymphocyte ratio (NLR), have been identified as predict ICI efficacy in patients with various cancers. We retrospectively enrolled 36 TNBC patients who received atezolizumab treatment between September 2019 and May 2021 at eight Japanese medical institutions. We evaluated systemic immunity markers, including dynamic changes in these markers, as predictors of survival benefit derived from atezolizumab treatment. Median time-to-treatment failure (TTF) and overall survival (OS) were 116 days and "not reached", respectively. Patients with low NLR at baseline and decreased NLR at the start of the second cycle (SO2nd) had significantly longer OS than those with high NLR at baseline and increased NLR (SO2nd) (log-rank P < 0.001 and log-rank P = 0.049, respectively). Multivariate analyses identified high ALC at baseline and decreased NLR (SO2nd) as independent predictive markers for longer TTF (P = 0.043 and P = 0.002, respectively), and low NLR at baseline and decreased NLR (SO2nd) as independent predictive markers for longer OS (P < 0.001 and P = 0.013, respectively). The safety profile was consistent with those of previous trials. This retrospective multicenter observational study showed the clinical efficacy and safety of atezolizumab treatment. Furthermore, systemic immunity markers, including their dynamic changes, were found to be associated with clinical outcomes of atezolizumab treatment in patients with advanced or metastatic TNBC.

Pembrolizumab plus chemotherapy in Japanese patients with triple-negative breast cancer: Results from KEYNOTE-355.

Pembrolizumab plus chemotherapy improved progression-free survival (PFS) and overall survival (OS) compared with placebo plus chemotherapy in patients with previously untreated locally recurrent inoperable or metastatic triple-negative breast cancer with tumor programmed cell death ligand 1 (PD-L1) combined positive score (CPS) ≥10 in the global, phase 3, randomized controlled trial KEYNOTE-355. We report results for patients enrolled in Japan. Patients were randomized 2:1 to pembrolizumab 200 mg or placebo Q3W for 35 cycles plus chemotherapy (nab-paclitaxel, paclitaxel, or gemcitabine-carboplatin). Primary endpoints were PFS per RECIST version 1.1 by blinded independent central review and OS in patients with PD-L1 CPS ≥10, PD-L1 CPS ≥1, and the intention-to-treat (ITT) population. No alpha was assigned to this exploratory analysis. Eighty-seven patients were randomized in Japan (pembrolizumab plus chemotherapy, n = 61; placebo plus chemotherapy, n = 26), 66 (76%) had PD-L1 CPS ≥1, and 28 (32%) had PD-L1 CPS ≥10. Median time from randomization to data cutoff (June 15, 2021) was 44.7 (range, 37.2-52.9) months in the ITT population. Hazard ratios (HRs; 95% CI) for OS were 0.36 (0.14-0.89), 0.52 (0.30-0.91), and 0.46 (0.28-0.77) in the PD-L1 CPS ≥10, PD-L1 CPS ≥1, and ITT populations, respectively. HRs (95% CI) for PFS were 0.52 (0.20-1.34), 0.61 (0.35-1.06), and 0.64 (0.39-1.05). Grade 3 or 4 treatment-related adverse events occurred in 85% of patients in each group (no grade 5 events). Consistent with the global population, pembrolizumab plus chemotherapy tended to show improvements in OS and PFS with manageable toxicity versus placebo plus chemotherapy in Japanese patients and supports this combination in this setting.

Bi-weekly eribulin therapy for metastatic breast cancer: a multicenter phase II prospective study (JUST-STUDY).

BACKGROUND: This study aimed to investigate whether schedule modification is safe and effective in patients intolerant to the standard eribulin dose and schedule. METHODS: Patients with metastatic breast cancer (MBC) treated with both anthracycline and taxane and ≤ 3 prior regimens of chemotherapy for MBC received eribulin at the standard dose and schedule (1.4 mg/m2 on days 1 and 8 of a 21-day cycle) in the first cycle; change of dosing schedule (1.4 mg/m2 on days 1 and 15 of a 28-day cycle) was determined by change in neutrophil count, platelet count, aspartate aminotransferase, alanine aminotransferase, total bilirubin, serum creatinine, and non-hematological toxicity on day 8 of the first cycle or day 1 of the second cycle. Clinical benefit rate (CBR; primary endpoint), time to treatment failure (TTF), overall survival (OS), and safety were evaluated. RESULTS: Of the 88 patients who were enrolled and received standard eribulin therapy in the first cycle, 42 patients were moved to the bi-weekly therapy group and 40 continued standard therapy. In the bi-weekly and standard therapy groups, mean relative dose intensity was 62.7 and 90.9%, CBR was 31.0 and 25.0%, median TTF was 81.5 and 75 days, and OS was 523 and 412 days, respectively. Neither group reported severe adverse events. CONCLUSION: This is the first study to show that a bi-weekly eribulin schedule is tolerable and has comparable efficacy in patients intolerant to the standard eribulin schedule. CLINICAL TRIAL REGISTRATION: University Hospital Medical Information Network (UMIN) Center (ID: UMIN 000008491).

Estrogen receptor (ER) mRNA expression and molecular subtype distribution in ER-negative/progesterone receptor-positive breast cancers.

We examined estrogen receptor (ER) mRNA expression and molecular subtypes in stage I-III breast cancers that are progesterone receptor (PR) positive but ER and HER2 negative by immunohistochemistry (IHC) or fluorescent in situ hybridization. The ER, PR, and HER2 status was determined by IHC as part of routine clinical assessment (N = 501). Gene expression profiling was done with the Affymetrix U133A gene chip. We compared expressions of ESR1 and MKI67 mRNA, distribution of molecular subtypes by the PAM50 classifier, the sensitivity to endocrine therapy index, and the DLDA30 chemotherapy response predictor signature among ER/PR-positive (n = 223), ER-positive/PR-negative (n = 73), ER-negative/PR-positive (n = 20), and triple-negative (n = 185) cancers. All patients received neoadjuvant chemotherapy with an anthracycline and taxane and had adjuvant endocrine therapy only if ER or PR > 10 % positive. ESR1 expression was high in 25 % of ER-negative/PR-positive, in 79 % of ER-positive/PR-negative, in 96 % of ER/PR-positive, and in 12 % of triple-negative cancers by IHC. The average MKI67 expression was significantly higher in the ER-negative/PR-positive and triple-negative cohorts. Among the ER-negative/PR-positive patients, 15 % were luminal A, 5 % were Luminal B, and 65 % were basal like. The relapse-free survival rate of ER-negative/PR-positive patients was equivalent to ER-positive cancers and better than the triple-negative cohort. Only 20-25 % of the ER-negative/PR-positive tumors show molecular features of ER-positive cancers. In this rare subset of patients (i) a second RNA-based assessment may help identifying the minority of ESR1 mRNA-positive, luminal-type cancers and (ii) the safest clinical approach may be to consider both adjuvant endocrine and chemotherapy.