PURPOSE: The role of maintenance therapy for gastric (GC) or gastroesophageal junction cancer (GEJC) is unclear. We investigated avelumab (anti–programmed death ligand-1 [PD-L1]) maintenance after first-line induction chemotherapy for GC/GEJC. PATIENTS AND METHODS: JAVELIN Gastric 100 was a global, open-label, phase III trial. Eligible patients had untreated, unresectable, human epidermal growth factor receptor 2–negative, locally advanced or metastatic GC or GEJC. Patients without progressive disease after 12 weeks of first-line chemotherapy with oxaliplatin plus a fluoropyrimidine were randomly assigned 1:1 to avelumab 10 mg/kg every 2 weeks or continued chemotherapy, stratified by region (Asia v non-Asia). The primary end point was overall survival (OS) after induction chemotherapy in all randomly assigned patients or the PD-L1–positive randomly assigned population (≥ 1% of tumor cells; 73-10 assay). RESULTS: A total of 805 patients received induction; 499 were randomly assigned to avelumab (n = 249) or continued chemotherapy (n = 250). Median OS was 10.4 months (95% CI, 9.1 to 12.0 months) versus 10.9 months (95% CI, 9.6 to 12.4 months) and 24-month OS rate was 22.1% versus 15.5% with avelumab versus chemotherapy, respectively (hazard ratio [HR], 0.91; 95% CI, 0.74 to 1.11; P = .1779). In the PD-L1–positive population (n = 54), the HR for OS was 1.13 (95% CI, 0.57 to 2.23; P = .6352). In an exploratory analysis of the PD-L1–positive population, defined as combined positive score ≥ 1 (22C3 assay; n = 137), median OS was 14.9 months (95% CI, 8.7 to 17.3 months) with avelumab versus 11.6 months (95% CI, 8.4 to 12.6 months) with chemotherapy (unstratified HR, 0.72; 95% CI, 0.49 to 1.05). With avelumab and chemotherapy, treatment-related adverse events (TRAEs) occurred in 149 (61.3%) and 184 (77.3%) patients, including grade ≥ 3 TRAEs in 31 (12.8%) and 78 (32.8%) patients, respectively. CONCLUSION: JAVELIN Gastric 100 did not demonstrate superior OS with avelumab maintenance versus continued chemotherapy in patients with advanced GC or GEJC overall or in a prespecified PD-L1–positive population.

This analysis was performed to further characterise treatment-emergent hypocalcaemia in patients with bone metastases receiving denosumab. Laboratory abnormalities and adverse events of hypocalcaemia in patients with metastatic bone disease were analysed using data from three identically designed phase 3 trials of subcutaneous denosumab 120 mg (n = 2841) versus intravenous zoledronic acid 4 mg (n = 2836). The overall incidence of laboratory events of hypocalcaemia grade ⩾ 2 was higher with denosumab (12.4%) than with zoledronic acid (5.3%). Hypocalcaemia events were primarily grade 2 in severity and usually occurred within the first 6 months of treatment. Patients who reported taking calcium and/or vitamin D supplements had a lower incidence of hypocalcaemia. Prostate cancer or small-cell lung cancer, reduced creatinine clearance and higher baseline bone turnover markers of urinary N-telopeptide of type I collagen (uNTx; > 50 versus ⩽ 50 nmol/mmol) and bone-specific alkaline phosphatase (BSAP; > 20.77 μg/L [median] versus ⩽ 20.77 μg/L) values were important risk factors for developing hypocalcaemia. The risk associated with increased baseline BSAP levels was greater among patients who had > 2 bone metastases at baseline versus those with ⩽ 2 bone metastases at baseline. Hypocalcaemia was more frequent with denosumab versus zoledronic acid, consistent with denosumab's greater antiresorptive effect. Low serum calcium levels and potential vitamin D deficiency should be corrected before initiating treatment with a potent osteoclast inhibitor, and corrected serum calcium levels should be monitored during treatment. Adequate calcium and vitamin D intake appears to substantially reduce the risk of hypocalcaemia.

DESTINY-Breast01 (NCT03248492) evaluated trastuzumab deruxtecan (T-DXd; DS-8201) in patients with heavily pretreated HER2-positive metastatic breast cancer (mBC). We present a subgroup of 24 patients with a history of treated brain metastases (BM), a population with limited treatment options. In patients with BMs, the confirmed objective response rate (cORR) was 58.3% [95% confidence interval (CI), 36.6%–77.9%], and the median progression-free survival (mPFS) was 18.1 months (95% CI, 6.7–18.1 months). In patients without BMs (n = 160), cORR was 61.3% and mPFS was 16.4 months. Eight patients (47.1%) experienced a best overall intracranial response of partial response or complete response. Seven patients (41.2%) had a best percentage change in brain lesion diameter from baseline consistent with stable disease. Two patients (8.3%) with BMs and two (1.3%) without BMs experienced progression in the brain. The safety profile of T-DXd was consistent with previous studies. The durable clinical activity of T-DXd in this population warrants further investigation. Significance: Advances in treating HER2-positive metastatic breast cancer have greatly improved patient outcomes, but intracranial progression remains an important risk for which few therapeutic options are currently available. T-DXd demonstrated durable efficacy in patients with stable, treated BMs. This article is highlighted in the In This Issue feature, p. 2711

Background Hormone receptor (HR)-positive breast cancer is a disease for which no immune checkpoint inhibitors have shown promise as effective therapies. Cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors synergistically increased the effectiveness of antiprogrammed cell death protein-1 (anti-PD-1)/programmed death-ligand 1 (PD-L1) antibodies in preclinical studies. Methods This non-randomized, multicohort, phase II study evaluated the efficacy and safety of the anti-PD-1 antibody nivolumab 240 mg administered every 2 weeks in combination with the CDK4/6 inhibitor abemaciclib 150 mg twice daily and either fulvestrant (FUL) or letrozole (LET) as a first-line or second-line treatment for HR-positive HER2-negative metastatic breast cancer. The primary end point was the objective response rate (ORR), and secondary end points were toxicity, progression-free survival, and overall survival. Blood, tissue, and fecal samples were collected at multiple points for correlative studies to evaluate immunity biomarkers. Results From June 2019 to early study termination due to safety concerns on July 2020, 17 patients were enrolled (FUL: n=12, LET: n=5). One patient with a prior treatment history in the FUL cohort was excluded. ORRs were 54.5% (6/11) and 40.0% (2/5) in the FUL and LET cohorts, respectively. Treatment-emergent (TE) adverse events (AEs) of grade ≥3 occurred in 11 (92%) and 5 (100%) patients in the FUL and LET cohorts, respectively. The most common grade ≥3 TEAEs were neutropenia (7 (58.3%) and 3 (60.0%) in the FUL and LET cohorts, respectively), followed by alanine aminotransferase elevation (5 (41.6%) and 4 (80.0%)). One treatment-related death from interstitial lung disease occurred in the LET cohort. Ten patients developed liver-related grade ≥3 AEs. Liver biopsy specimens from 3 patients showed hepatitis characterized by focal necrosis with predominant CD8+ lymphocyte infiltration. Marked elevation of tumor necrosis factor-related cytokines and interleukin-11, and a decrease in peripheral regulatory T cells (Tregs), were observed in patients with hepatotoxicity. These findings suggest that treatment-related toxicities were immune-related AEs likely caused by proinflammatory cytokine production and suppression of Treg proliferation due to the addition of abemaciclib to nivolumab therapy. Conclusions Although the combination of nivolumab and abemaciclib was active, it caused severe and prolonged immune-related AEs. Trial registration number JapicCTI-194782, jRCT2080224706, UMIN000036970.

Nausea and vomiting are common adverse events associated with trastuzumab deruxtecan (T-DXd). We evaluated the efficacy of an olanzapine-based triplet regimen for preventing nausea and vomiting in patients receiving first cycle T-DXd. This multi-institutional, randomized, double-blind, placebo-controlled (ERICA) phase II study enrolled patients with HER2-positive/HER2-low metastatic breast cancer receiving their first cycle of T-DXd. Patients were randomized to olanzapine 5 mg or placebo once daily (1:1 ratio) from Day 1 to 6, plus a 5-hydroxytryptamine type 3-receptor antagonist (5-HT₃RA) and dexamethasone 6.6 mg intravenously or 8 mg orally on Day 1. The total observation period was 504 hours (21 days) from the first T-DXd administration. The primary endpoint was complete response (CR), defined as no emetic events and no rescue medications, in the delayed phase (24-120 hours post-T-DXd), with the type I error rate of 0.2 (one-sided) for the comparison. Secondary endpoints included no nausea rate in the delayed and persistent phases (120-504 hours), adverse event by CTCAE and PRO-CTCAE. In total, 168 patients were enrolled at 43 sites in Japan (Nov 2021-Sep 2023) with 162 patients (olanzapine, n = 80; placebo, n = 82) included in the per protocol set. The primary endpoint was met as the delayed phase CR rate was significantly greater with olanzapine than placebo (70.0% versus 56.1%, P = 0.047). Efficacy was maintained in the persistent phase (63.9% versus 44.4%). No nausea rate was also greater with olanzapine (delayed phase: 57.5% versus 37.8%; persistent phase: 51.4% versus 31.9%). CR rates in the delayed phase favored olanzapine across subgroups. Appetite loss was also decreased with olanzapine. Hyperglycemia and somnolence were mostly of low-grade severity. Olanzapine 5mg for 6 days with 5-HT₃RA and dexamethasone appears effective for T-DXd-treated patients to prevent delayed and persistent nausea and vomiting.