PURPOSE: Human epidermal growth factor receptor 3 (HER3) is broadly expressed in breast cancer; high expression is associated with an adverse prognosis. Patritumab deruxtecan (HER3-DXd) is an investigational HER3-targeted antibody-drug conjugate that is being evaluated as a novel treatment in HER3-expressing advanced breast cancer in the U31402-A-J101 study. METHODS: Adults with disease progression on previous therapies were eligible. Patients in the dose-escalation, dose-finding, and dose-expansion parts received HER3-DXd 1.6-8.0 mg/kg intravenously once every 3 weeks or one of two alternative dosing regimens. In the dose-escalation part, the primary objectives were to determine the maximum tolerated dose and recommended dose for expansion (RDE). The safety and efficacy of the RDE were assessed during dose expansion. RESULTS: One hundred eighty-two enrolled patients received ≥1 dose of HER3-DXd. Patients had a median of five previous therapies for advanced disease. Efficacy results are reported across clinical subtypes: hormone receptor–positive (HR+)/human epidermal growth factor receptor 2–negative (HER2-negative) breast cancer (n = 113; objective response rate [ORR], 30.1%; median progression-free survival [mPFS], 7.4 months), triple-negative breast cancer (n = 53; ORR, 22.6%; mPFS, 5.5 months), and HER2-positive breast cancer (n = 14; ORR, 42.9%; mPFS, 11.0 months). Objective responses were observed in cancers with HER3-high and HER3-low membrane expression. Dose-limiting toxicities observed during dose selection were decreased platelet count and elevated aminotransferases. In dose expansion, GI and hematologic toxicities were the most common treatment-emergent adverse events (TEAEs) observed. Grade ≥3 TEAEs were observed in 71.4% of patients, and 9.9% discontinued treatment because of TEAEs. Three grade 3 and one grade 5 treatment-related interstitial lung disease events occurred. CONCLUSION: HER3-DXd demonstrated a manageable safety profile and durable efficacy in heavily pretreated patients across clinical subtypes. These data warrant further evaluation of HER3-DXd in patients with HER3-expressing metastatic breast cancer.

Aim: To investigate the safety and efficacy of lenvatinib in advanced thyroid cancer. Patients/methods: In this Phase II study, 51 Japanese patients with radioiodine-refractory differentiated thyroid cancer (RR-DTC), medullary thyroid cancer (MTC) or anaplastic thyroid cancer (ATC) received once-daily lenvatinib 24 mg. The primary end point was safety. Results: All patients experienced ≥1 adverse event (AE); only one patient experienced an AE leading to discontinuation. The most common any-grade AEs were hypertension, decreased appetite, palmar-plantar erythrodysesthesia, fatigue and proteinuria. Response rates for RR-DTC: 68%; MTC: 22%; ATC: 24%. Median progression-free survival for RR-DTC: 25.8 months; MTC: 9.2 months; ATC: 7.4 months. Conclusion: Lenvatinib demonstrated a manageable safety profile, proven antitumor activity in RR-DTC and promising efficacy in MTC and ATC. Clinical trial registration: clinicaltrials.gov NCT01728623 Lay abstract Lenvatinib is approved in Japan and elsewhere to treat radioiodine-refractory differentiated thyroid cancer; however, new therapies are also needed for other forms of advanced thyroid cancer (such as medullary thyroid cancer and anaplastic thyroid cancer). Fifty-one patients from Japan with advanced thyroid cancer received lenvatinib in this clinical trial. All patients experienced at least one side effect during treatment but only one patient experienced a side effect that necessitated stopping lenvatinib therapy. In general, patients tolerated lenvatinib treatment because the side effects were manageable. Lenvatinib treatment showed promising antitumor effects for patients across all thyroid cancer subtypes tested.

PURPOSE: To evaluate the efficacy and safety of tucatinib and trastuzumab in patients with previously treated human epidermal growth factor receptor 2–positive (HER2+) metastatic biliary tract cancer (mBTC). METHODS: SGNTUC-019 (ClinicalTrials.gov identifier: NCT04579380 ) is an open-label phase II basket study evaluating the efficacy and safety of tucatinib and trastuzumab in patients with HER2-altered solid tumors. In the biliary tract cancer cohort, patients had previously treated HER2 overexpressing or amplified (HER2+) tumors (identified with local testing) with no prior HER2-directed therapy. The primary end point was confirmed objective response rate (cORR) per investigator assessment. Patients were treated on a 21-day cycle with tucatinib (300 mg orally twice daily) and trastuzumab (8 mg/kg intravenously followed by 6 mg/kg every 3 weeks). RESULTS: Thirty patients were enrolled. As of data cutoff (January 30, 2023), the median duration of follow-up was 10.8 months. The cORR was 46.7% (90% CI, 30.8 to 63.0), with a disease control rate of 76.7% (90% CI, 60.6 to 88.5). The median duration of response and progression-free survival were 6.0 months (90% CI, 5.5 to 6.9) and 5.5 months (90% CI, 3.9 to 8.1), respectively. At data cutoff, 15 patients (50.0%) had died, and the estimated 12-month overall survival rate was 53.6% (90% CI, 36.8 to 67.8). The two most common treatment-emergent adverse events (TEAEs) were pyrexia (43.3%) and diarrhea (40.0%). Grade ≥3 TEAEs were reported in 18 patients (60.0%), with the most common being cholangitis, decreased appetite, and nausea (all 10.0%), which were generally not treatment related. TEAEs led to treatment regimen discontinuation in one patient, and there were no deaths due to TEAEs. CONCLUSION: Tucatinib combined with trastuzumab had clinically significant antitumor activity and was well tolerated in patients with previously treated HER2+ mBTC.

To assess efficacy and safety of nivolumab versus investigator's choice of therapy (IC) in Asian patients with platinum-refractory recurrent or metastatic squamous cell carcinoma of the head and neck (SCCHN). Thirty-four patients from Japan, Taiwan, Hong Kong, and Korea received nivolumab 3mg/kg (n=23) every 2weeks or IC (n=11), as part of a global trial (n=361), until intolerable toxicity or disease progression. The primary endpoint was overall survival (OS). Median OS was 9.5months (95% confidence interval [CI] 9.1-NR) with nivolumab and 6.2months (95% CI 2.6-NR) with IC. Seven (30.4%) patients receiving nivolumab and six (54.5%) receiving IC died. The hazard ratio (HR) for risk of death (nivolumab vs. IC) was 0.50 (95% CI 0.17-1.48). Median progression-free survival was 1.9months (95% CI 1.6-7.5) with nivolumab and 1.8months (95% CI 0.4-6.1) with IC (HR 0.57 [95% CI 0.25-1.33]). Objective response rates (complete+partial responses) were 26.1% (6/23 patients; 95% CI 10.2-48.4) for nivolumab and 0% (0/11 patients; 95% CI 0.0-28.5) for IC. Sixteen (69.6%) nivolumab-treated patients and 10 (90.9%) patients receiving IC had a treatment-related adverse event, most commonly decreased appetite (21.7%), pruritus, rash, and fatigue (17.4% each) with nivolumab, and nausea, stomatitis, and decreased appetite (27.3% each) with IC. Nivolumab demonstrated a survival advantage compared with conventional treatments in Asian patients with platinum-refractory recurrent or metastatic SCCHN, and was well tolerated. Clinical trial registration NCT02105636.

Summary: Locally advanced or metastatic urothelial cancer is an aggressive form of cancer with high recurrence rates and low survival. Nectin-4 is a cell adhesion molecule commonly expressed in several tumors, including high expression in urothelial cancer. Enfortumab vedotin is an antibody–drug conjugate composed of an anti-Nectin-4 humanized monoclonal antibody linked to the microtubule disrupting agent, monomethyl auristatin E. In this phase I study (NCT03070990), Japanese patients with locally advanced/metastatic urothelial cancer treated with prior chemotherapy, or ineligible for cisplatin, were randomized 1:1 to receive 1.0 mg/kg (Arm A) or 1.25 mg/kg (Arm B) enfortumab vedotin on Days 1, 8, and 15 of each 28-day cycle. Assessing the pharmacokinetic and safety/tolerability profiles of enfortumab vedotin were primary objectives; investigator-assessed antitumor activity (RECIST v1.1) was a secondary objective. Seventeen patients (n = 9, Arm A; n = 8, Arm B) received treatment. Pharmacokinetic data suggest a dose-dependent increase in enfortumab vedotin maximum concentration and area under the concentration–time curve at Day 7. Enfortumab vedotin was well tolerated across both doses. Dysgeusia and alopecia (n = 9 each) were the most common treatment-related adverse events. Regardless of attribution, grade ≥ 3 adverse events occurring in ≥2 patients were anemia and hypertension (n = 2 each). One patient achieved a confirmed complete response (Arm A) and five achieved confirmed partial responses (n = 3, Arm A; n = 2, Arm B). Objective response and disease control rates were 35.3% and 76.5%, respectively. In Japanese patients with locally advanced/metastatic urothelial cancer, enfortumab vedotin is well tolerated with preliminary antitumor activity and a pharmacokinetic profile consistent with prior reports.

Background: A standard chemotherapy for recurrent/metastatic salivary gland cancers has not been established. Combination chemotherapy of carboplatin and paclitaxel should be evaluated as a treatment option. Methods: This study retrospectively reviewed salivary gland cancer patients who received combination chemotherapy of carboplatin and paclitaxel. The differences in objective responses and in the prognoses according to the different pathological diagnoses were evaluated. Results: A total of 38 patients were enrolled in the study; of them, 18 had salivary duct carcinomas (SDCs), nine had adenoid cystic carcinomas (ACCs), and 11 had other pathological diagnoses. Objective responses were observed in 15 (39%) patients. The median progression-free survival (PFS) was 6.5 months, and the median overall survival (OS) was 26.5 months. ACC patients had relatively low response rates (9%), but there were no significant differences in PFS or OS compared to other sub-types. The treatment was well tolerated, with few adverse events. Conclusion: Salivary gland cancer patients showed a moderate clinical response to the combination chemotherapy of carboplatin and paclitaxel. The objective response rates differed according to the pathological diagnoses, but there were no significant differences in prognoses.