Herceptin (trastuzumab) / Roche - LARVOL DELTA

Atezolizumab and Trastuzumab Plus Chemotherapy for ERBB2-Positive Locally Advanced Resectable Gastric Cancer: A Randomized Clinical Trial. (PubMed, JAMA Oncol) - P2 | "In this randomized clinical trial, add-on atezolizumab to trastuzumab plus XELOX therapy demonstrated promising efficacy in this patient population, and no new safety concerns were raised. ClinicalTrials.gov Identifier: NCT04661150."

Clinical • Journal • Esophageal Cancer • Gastric Cancer • Gastroesophageal Junction Adenocarcinoma • Oncology • Solid Tumor • HER-2

De-escalated neoadjuvant taxane plus trastuzumab and pertuzumab with or without carboplatin in HER2-positive early breast cancer (neoCARHP): A multicentre, open-label, randomised, phase 3 trial. (ASCO 2025) - P3 | "Patients were stratified by nodal and hormone receptor status and randomized (1:1) to receive six 3-week cycles of an investigator-selected taxane (docetaxel, paclitaxel or nab-paclitaxel) plus trastuzumab (8 mg/kg loading dose, then 6 mg/kg every 3 weeks) and pertuzumab (840 mg loading dose, then 420 mg every 3 weeks), with carboplatin (TCbHP; AUC 6 mg/mL per min) or without carboplatin (THP). THP provided non-inferior pCR rates and improved tolerability compared with TCbHP. Omitting carboplatin could be an efficacious de-escalated neoadjuvant strategy in the presence of dual HER2 blockade for patients with HER2-positive early breast cancer."

Clinical • Late-breaking abstract • P3 data • Breast Cancer • HER2 Breast Cancer • HER2 Positive Breast Cancer • Hormone Receptor Breast Cancer • Leukopenia • Neutropenia • Oncology • Solid Tumor • HER-2

Trastuzumab deruxtecan (T-DXd) + pertuzumab (P) vs taxane + trastuzumab + pertuzumab (THP) for first-line (1L) treatment of patients (pts) with human epidermal growth factor receptor 2–positive (HER2+) advanced/metastatic breast cancer (a/mBC): Interim results from DESTINY-Breast09. (ASCO 2025) - P3 | "T-DXd + P demonstrated a statistically significant and clinically meaningful improvement in PFS vs THP that was consistently observed across all subgroups and may represent a new 1L standard of care in HER2+ a/mBC; no new safety signals were identified. NC, not calculable."

Clinical • Late-breaking abstract • Metastases • Breast Cancer • HER2 Breast Cancer • HER2 Positive Breast Cancer • Inflammation • Interstitial Lung Disease • Oncology • Pneumonia • Pulmonary Disease • Respiratory Diseases • Solid Tumor • HER-2 • PIK3CA

Phase IB and II study of ribociclib with trastuzumab plus endocrine therapy in HR+/HER2+ advanced breast cancer patients: Korean Cancer Study Group BR 18-2 MINI trial. (ASCO 2025) - P1/2 | "Ribociclib, trastuzumab, and letrozole as first-line therapy in HR+/HER2+ ABC demonstrated a median PFS of 30.4 months with a manageable safety profile, supporting its potential as a chemotherapy-free option."

Clinical • Metastases • P1 data • Breast Cancer • Dermatology • HER2 Breast Cancer • HER2 Negative Breast Cancer • HER2 Positive Breast Cancer • Hormone Receptor Breast Cancer • Neutropenia • Oncology • Pruritus • Solid Tumor • HER-2

Palbociclib and trastuzumab for HER2-positive metastatic breast cancer: final overall survival results of cohort A and B of SOLTI-1303-PATRICIA trial. (PubMed, ESMO Open) - P2 | "These findings highlight the relevance of gene expression profiling in HER2-positive breast cancer and support biomarker-driven patient selection. Long-term PATRICIA results validate the potential of non-chemotherapy-based approaches in HR-positive/HER2-positive MBC."

Journal • Breast Cancer • HER2 Breast Cancer • HER2 Positive Breast Cancer • Oncology • Solid Tumor • ER • HER-2

KN026 in combination with chemotherapy for previously treated HER2-positive gastric or gastroesophageal carcinomas (GC/GEJC): Interim analysis of KC-WISE (ESMO 2025) - P2/3 | "Treatment-related deaths were reported in 0 and 5 patients in the anbenitamab and control groups, respectively. Conclusions Compared with chemotherapy alone, anbenitamab plus chemotherapy demonstrated clinically meaningful superior PFS and OS in patients with HER2-positive GC/GEJ adenocarcinoma whose previous therapy containing trastuzumab had failed."

Combination therapy • Late-breaking abstract • Esophageal Cancer • Gastric Cancer • Gastroesophageal Cancer • Gastroesophageal Junction Adenocarcinoma • Gastrointestinal Cancer • Oncology • HER-2

Her2climb-05: a randomized, double-blind, phase 3 study of tucatinib versus placebo in combination with trastuzumab and pertuzumab as maintenance therapy for her2+ metastatic breast cancer (SABCS 2025) - P3 | "In the HER2CLIMB-05 trial, the addition of tucatinib to TRAS + PERT as 1L maintenance therapy demonstrated a statistically significant and clinically meaningful improvement in PFS with a manageable safety profile in patients with HER2+ MBC."

Clinical • Combination therapy • Metastases • P3 data • Breast Cancer • HER2 Breast Cancer • HER2 Positive Breast Cancer • Hormone Receptor Breast Cancer • Hormone Receptor Positive Breast Cancer • HER-2

Tumor infiltrating lymphocytes (TILs) and pathologic complete response (pCR) in stage II/III HER2+ breast cancer treated with taxane, trastuzumab, and pertuzumab (THP): secondary results from the ECOG-ACRIN EA1181/CompassHER2 pCR trial (SABCS 2025) - P2 | " EA1181 (NCT04266249) enrolled patients (pts) with anatomic clinical stage II/III HER2+ breast cancer who preoperatively received 4 cycles of trastuzumab and pertuzumab with 12 weeks of paclitaxel or docetaxel q3w x 4 (THP), followed by surgery. sTILs were associated with pCR after THP, further supporting the important role of immune mechanisms in HER2+ breast cancer, and highlighting a potentially robust predictive tool to assess pathologic response. Baseline sTILs could potentially inform the preoperative design of future trials of therapy optimalization. Association of baseline sTILs with recurrence free survival in EA1181 will be reported in the future."

Clinical • Tumor-infiltrating lymphocyte • Breast Cancer • HER2 Breast Cancer • HER2 Positive Breast Cancer • Triple Negative Breast Cancer • HER-2

Trastuzumab deruxtecan (T-DXd) + pertuzumab (P) vs taxane + trastuzumab + pertuzumab (THP) for first-line (1L) treatment of Asian patients (pts) with HER2+ advanced/metastatic breast cancer (a/mBC): A DESTINY-Breast09 analysis (ESMO Asia 2025) - P3 | "T-DXd + P demonstrated consistent efficacy as 1L treatment in Asian pts with HER2+ a/mBC, with no new safety signals. Table: 88MO Data in brackets are 95% CIs. *Estimate may change at updated analysis BICR, blinded independent central review; CI, confidence interval; DOR, duration of response; INV, investigator; mo, months; NC, not calculable; PFS, progression-free survival; ORR, objective response rate"

Clinical • Metastases • Breast Cancer • HER2 Breast Cancer • HER2 Positive Breast Cancer • Oncology • Solid Tumor • HER-2 • PIK3CA

Adjuvant aromatase inhibitor or tamoxifen in patients with hormone receptor-positive/HER2-positive early breast cancer: An exploratory analysis from the ALTTO (BIG 2-06) trial (SABCS 2025) - "The present analysis investigated the efficacy of different types of ET in pts with centrally tested HR+/HER2+ EBC treated with modern chemotherapy (CT) and trastuzumab (T)-based regimens at 10-year follow-up.Patients and ALTTO (BIG 2-06) is an international phase 3 trial in pts with HER2+ EBC randomized to 4 adjuvant anti-HER2 treatments with CT: T alone, lapatinib (L) alone, their sequence (T->L) or their combination (T+L). In this large 10-year follow-up analysis of pts with centrally tested HR+/HER2+ EBC treated with modern CT+anti-HER2-based therapy in the ALTTO trial, the use of AI was associated with significantly improved DFS and TTDR without differences in OS. The DFS benefit of AI was observed in both premenopausal and postmenopausal pts. These data may help optimizing adjuvant ET choices in pts with HR+/HER2+ EBC and shed light on the need of designing ad hoc clinical trials in this setting."

Clinical • Breast Cancer • HER2 Breast Cancer • HER2 Positive Breast Cancer • Hormone Receptor Breast Cancer • Hormone Receptor Positive Breast Cancer • HER-2

Trastuzumab deruxtecan (T-DXd) + pertuzumab (P) vs taxane + trastuzumab + pertuzumab (THP) for first-line (1L) treatment of patients (pts) with HER2-positive (HER2+) advanced/metastatic breast cancer (a/mBC): patient-reported outcomes (PROs) from the DESTINY-Breast09 study (SABCS 2025) - P3 | "T-DXd + P was associated with more gastrointestinal symptoms but fewer skin/mucosal, nosebleed, and extremity swelling symptoms vs THP. Pain, fatigue, physical function, and overall patient-reported treatment impact were similar between regimens. Complementing the efficacy and safety results, PRO data support T-DXd + P as a new 1L treatment in HER2+ a/mBC providing durable pain control and maintenance of physical function, with distinct quality of life advantages compared with THP."

Clinical • Metastases • Patient reported outcomes • Breast Cancer • HER2 Breast Cancer • HER2 Positive Breast Cancer • Oncology • Solid Tumor • HER-2

Efficacy of maintenance endocrine therapy combined with trastuzumab + pertuzumab following taxane induction in HR+/HER2+ metastatic breast cancer: A real-world reproduction of the PATINA trial control arm. (SABCS 2025) - "Background: The PATINA trial demonstrated that adding the CDK4/6 inhibitor palbociclib to maintenance endocrine therapy (ET) and trastuzumab ± pertuzumab significantly prolonged median progression-free survival (PFS) by approximately 15 months (HR 0.74 [95% CI: 0.58-0.94]). In this real-world analysis, patients with HR+/HER2+ MBC treated with first-line metastatic induction chemotherapy followed by maintenance trastuzumab + pertuzumab and ET achieved outcomes in line with those reported in the control arm of the PATINA trial."

Clinical • Metastases • Real-world • Real-world evidence • Breast Cancer • HER2 Breast Cancer • HER2 Positive Breast Cancer • Hormone Receptor Breast Cancer • Oncology • Solid Tumor • HER-2

Efficacy Analysis of the Randomized Phase III DETECT V trial: Treatment De-escalation by Omission of Chemotherapy and the Effect of Adding Ribociclib in HER2-positive and Hormone-receptor Positive Metastatic Breast Cancer (SABCS 2025) - "The aim of the randomized multicenter phase III DETECT V trial was to analyze the efficacy of chemotherapy free and CDK4/6 inhibitor containing treatment strategies compared to current standard treatment. Between 09/2015 and 11/2022, 271 patients with HER2+ and HR+ MBC in the 1st-3rd line setting were randomized 1:1 to receive trastuzumab and pertuzumab combined with either endocrine therapy or chemotherapy followed by maintenance therapy with dual HER2 targeted and endocrine therapy. Our results suggest that chemotherapy-free treatment for patients with HER2+ and HR+ MBC may be a valuable and effective treatment alternative, and may improve survival with the addition of ribociclib."

Clinical • Metastases • P3 data • Breast Cancer • HER2 Breast Cancer • HER2 Positive Breast Cancer • Hormone Receptor Breast Cancer • Hormone Receptor Positive Breast Cancer • Oncology • Solid Tumor • HER-2

Radiation Therapy Followed by Intrathecal (IT) Trastuzumab/Pertuzumab in the Management of HER2+ Breast Leptomeningeal Disease: Interim Results from a Phase II Multi-Institutional Study (SABCS 2025) - P1/2 | "The study met its predetermined endpoint for OS to warrant continuing enrollment in the second stage of the phase II trial. Initial trial results are encouraging with study therapy that is well tolerated."

Clinical • P2 data • Breast Cancer • HER-2

Gut microbiome composition predicts pathologic complete response in patients with early-stage HER2-positive breast cancer receiving neoadjuvant HER2-targeted therapy +/- immunotherapy with pembrolizumab (SABCS 2025) - "This study aimed to investigate the association between gut microbiome profiles and clinical outcomes in patients with early-stage HER2-positive (HER2+) breast cancer receiving neoadjuvant HER2-targeted therapy +/- immunotherapy with pembrolizumab (K) as part of the randomized phase II neoHIP trial. Patients with stage II-III HER2+ breast cancer were randomized to 3 treatment arms: Arm A consisted of paclitaxel (T), trastuzumab (H), and pertuzumab (P), THP; Arm B of THP-K; and Arm C of TH-K. This is the first study to demonstrate that the pre-operative gut microbiome influences response to ICI in patients with early-stage HER2+ breast cancer. Patients who achieved pCR had a significantly different microbiome profile compared to those with residual disease. This study highlights the role of the gut microbiome in influencing response to ICI in patients with breast cancer treated in the curative intent setting."

Clinical • Breast Cancer • HER2 Breast Cancer • HER2 Positive Breast Cancer • Oncology • Solid Tumor

Zanidatamab + chemotherapy (CT) ± tislelizumab for first-line (1L) HER2-positive (HER2+) locally advanced, unresectable, or metastatic gastroesophageal adenocarcinoma (mGEA): Primary analysis from HERIZON-GEA-01. (ASCO-GI 2026) - P3 | "Background: HERIZON-GEA-01 (NCT05152147) is a global, open-label, phase 3 trial of zanidatamab (dual HER2-targeted bispecific antibody) + CT ± tislelizumab (anti–PD-1) vs trastuzumab (tras) + CT in 1L HER2+ mGEA. Eligible patients (pts) with previously untreated HER2+ mGEA, regardless of PD-L1 status, were randomized (1:1:1) to zanidatamab (1800 mg [12 mo) vs tras + CT. Zanidatamab + tislelizumab + CT also provided a statistically significant and clinically meaningful OS benefit (mOS >26 mo). The trial is ongoing with additional OS analyses planned for zanidatamab + CT."

Clinical • Late-breaking abstract • Metastases • Esophageal Adenocarcinoma • Esophageal Cancer • Gastroesophageal Junction Adenocarcinoma • Gastrointestinal Cancer • Oncology • Solid Tumor • HER-2

Tucatinib, trastuzumab, and capecitabine with stereotactic radiosurgery in patients with brain metastases from HER-2 positive breast cancer (TUTOR): Study protocol for a multicenter phase 1 clinical trial. (PubMed, BMC Cancer) - P1 | "This trial has been approved by the Institutional Review Board (IRB) and began patient enrollment in January 2024. The trial will provide insights into the safety and effectiveness of a novel combinatorial therapy for BCBM."

Journal • P1 data • Brain Cancer • Breast Cancer • Febrile Neutropenia • HER2 Breast Cancer • HER2 Positive Breast Cancer • Hormone Receptor Breast Cancer • Neutropenia • Solid Tumor • Thrombocytopenia • HER-2

Phase II trial of systemic therapy plus intraperitoneal (IP) paclitaxel (PTX) in gastric/GEJ cancer peritoneal carcinomatosis (GPC): STOPGAP trial. (ASCO-GI 2026) - "After diagnostic laparoscopy (diag lap), and IP port placement, pts were treated with IP PTX 40 mg/m2 plus IV PTX 50 mg/m2, leucovorin 20 mg/m2 and 5-fluorouracil 400 mg/m2 (bolus) on days1 and 8, every 21 days for 4 cycles. If indicated, anti-PD1 antibody +/- trastuzumab were continued as before enrollment... Iterative normothermic IP PTX plus systemic treatment in GPC is safe and feasible, with encouraging clinical efficacy and safety in historically poor risk patients. The ongoing Phase 2/3 EA2234 STOPGAP II randomized trial will investigate the OS benefit of this approach compared to systemic therapy alone. Median PFS and OS from diagnosis and on study (months (95% CI)."

P2 data • Gastric Cancer • Gastroesophageal Junction Adenocarcinoma • Gastrointestinal Cancer • Oncology

Neoadjuvant Taxane Plus Trastuzumab and Pertuzumab With or Without Carboplatin in Human Epidermal Growth Factor Receptor 2-Positive Breast Cancer: The Randomized Noninferiority Phase III neoCARHP Trial. (PubMed, J Clin Oncol) - "THP provided noninferior pCR rates and improved tolerability compared with TCbHP. Omitting carboplatin may be applicable in HER2-positive breast cancer."

Head-to-Head • Journal • P3 data • Breast Cancer • Hematological Disorders • HER2 Breast Cancer • HER2 Positive Breast Cancer • Leukopenia • Neutropenia • Oncology • Solid Tumor • HER-2

PD-L1-Binding Antigen Presenters: Redirecting Vaccine-Induced Antibodies for Cancer Immunotherapy. (PubMed, Adv Sci (Weinh)) - "For example, a PBAP-HER2 construct synergized with Herceptin and Kadcyla to eliminate human epidermal growth factor receptor 2 (HER2)-negative, PD-L1 positive cells. This work represents an innovative strategy for enhancing PD-L1-targeted therapies by leveraging pre-existing antibodies induced by vaccination or natural viral infections, alongside commercially available antibody-based therapies. Given the broad expression of PD-L1 across various solid tumors and hematologic malignancies, our strategy holds promise as a potentially widely applicable platform for diverse PD-L1-positive patient populations."

IO biomarker • Journal • Hematological Disorders • Hematological Malignancies • Herpes Zoster • Infectious Disease • Oncology • Solid Tumor • Varicella Zoster • HER-2 • PD-L1

Case Report: HER2-positive vulvar Paget disease achieving long-term control with trastuzumab-based systemic therapy plus radiotherapy. (PubMed, Front Med (Lausanne)) - "As surgery was not feasible, she received trastuzumab plus capecitabine, achieving marked tumor shrinkage. With trastuzumab maintenance, disease control has been sustained for 17 months. HER2-targeted therapy combined with chemotherapy and radiotherapy is a promising treatment strategy for HER2-positive, inoperable or recurrent VPD."

Journal • Oncology • Rare Diseases • Solid Tumor • HER-2

EVALUATING PRE-EXISTING IMMUNITY IN HER2+ BREAST CANCER PATIENTS WHO RECEIVE HER2 BREAST CANCER VACCINES (WRMC 2026) - "Exposure to trastuzumab is associated with development of HER2-specific Th1 immunity. Vaccination enhances HER2 Th1 regardless of trastuzumab exposure, including in patients who lacked pre-existing immunity. These findings support HER2-targeted vaccination as an immune-priming or immune-rescuing strategy, particularly for patients who remain immunologically unresponsive after antibody therapy."

Clinical • Breast Cancer • HER2 Breast Cancer • HER2 Positive Breast Cancer • Oncology • Solid Tumor • HER-2 • IFNG

Validation of the HER2DX genomic test in first-line advanced HER2-positive breast cancer treated with trastuzumab, pertuzumab, and taxane. (PubMed, NPJ Breast Cancer) - "In conclusion, the HER2DX ERBB2 mRNA score provides independent prognostic information in HER2+ advanced breast cancer treated with THP. The HER2DX metastatic prognostic score further improves prognostic accuracy."

Journal • Breast Cancer • HER2 Breast Cancer • HER2 Positive Breast Cancer • Oncology • Solid Tumor • HER-2

Olaparib plus trastuzumab in HER2-positive advanced breast cancer patients with germline BRCA1/2 mutations: The OPHELIA phase 2 study. (PubMed, Breast) - P2 | "This study suggests that the combination of olaparib plus trastuzumab may be effective and safe in pre-treated patients with HER2-positive gBRCAm ABC. This ABC patient population should be further studied and not be pre-emptively excluded from clinical trials of targeted therapy for BRCA1/2-driven cancers."

Journal • Metastases • P2 data • Breast Cancer • HER2 Breast Cancer • HER2 Positive Breast Cancer • Oncology • Solid Tumor • BRCA • BRCA1 • BRCA2 • HER-2

Phase 1a/b study of runimotamab, a HER2 x CD3 T cell-engaging bispecific antibody, administered as a single agent and in combination with trastuzumab in patients with HER2-expressing breast cancer (BC) (AACR 2025) - P1 | "Improved tolerability and higher runimotamab dose levels were achieved in combination with trastuzumab, compared to runimotamab alone. Runimotamab + trastuzumab demonstrated a manageable safety profile and encouraging clinical activity in heavily pretreated HER2-positive BC patients."

Clinical • Combination therapy • P1 data • Breast Cancer • HER2 Breast Cancer • HER2 Positive Breast Cancer • Oncology • Solid Tumor • HER-2