HER-2 exon 20 insertion

DS-8201 demonstrates potential as one of the effective salvage therapies following RC48 failure in HER2 altered solid tumors, showing significantly better disease control and a distinct, manageable toxicity profile. These findings highlight the importance of selecting personalized ADCs based on molecular subtypes and toxicity factors and provide a basis for future, larger-scale prospective studies.

In this small case series, T-DXd demonstrated encouraging antitumor activity and manageable safety in heavily pretreated patients with HER2 mutated, metastatic NSCLC. Although selected patients had durable benefits, the findings are anecdotal and should be interpreted with caution. Larger real‑world cohorts and prospective studies are needed to validate the consistency, durability, and safety of T‑DXd in routine clinical practice.

In contrast, such changes in CD8 + T cell infiltration and PD-1 expression were not evident in another HER2 20ins patient who received conventional chemotherapy. These findings suggest that neoadjuvant T-DXd may represent a promising therapeutic option for locally advanced HER2-mutant NSCLC, warranting further investigation in larger cohorts.

P1/2, N=345, Recruiting, Pierre Fabre Medicament | N=251 --> 345

P2, N=78, Recruiting, Shanghai Junshi Bioscience Co., Ltd. | N=42 --> 78 | Trial completion date: Apr 2027 --> Apr 2028 | Trial primary completion date: Sep 2025 --> Sep 2026

The second case involves a patient with metastatic micropapillary urothelial carcinoma with HER2 expression, refractory to platinum chemotherapy, avelumab maintenance, and enfortumab vedotin. These two observations illustrate the capacity of T-DXd to induce deep and complete metabolic remissions in distinct HER2-altered solid tumors. They support further development of HER2-targeted ADCs beyond traditional indications and highlight the value of FDG-PET/CT for assessing the depth of response to these agents.

She enrolled in a clinical trial of the selective HER2 tyrosine kinase inhibitor zongertinib (60 mg twice daily) in February 2025 and tolerated therapy well, with mild diarrhea, lactose intolerance, brittle nails, and intermittent muscle cramps...As of January 2026, she has maintained lung-confined disease control for over 11 months without extrapulmonary progression and remains fully functional without symptoms. This case highlights the clinical benefit and tolerability of selective HER2-targeted therapy in HER2-mutant NSCLC and adds to emerging evidence supporting consideration of risk-based lung cancer screening strategies in high-risk never-smoking populations.

Following isolation by prep-HPLC, 1D and 2D NMR studies and HRMS characterization assigned the isolate as Mobocertinib-N-oxide. In addition, NMR-based reaction monitoring was conducted to trace its formation, allowing a plausible mechanism of formation to be proposed.

The management of human epidermal growth factor receptor 2 (HER2)-mutant non-small cell lung cancer (NSCLC) remains a significant clinical challenge, with limited effective and accessible treatment options beyond antibody-drug conjugates such as trastuzumab deruxtecan (T-DXd)...Following chemotherapy and sintilimab failure in August 2025 due to progressive disease, furmonertinib rechallenge at 160 mg/day again induced a response within 5 days, with no grade ≥3 adverse events...The structural homology between HER2 p.Y772_A775dup and EGFR exon 20 "near-loop" insertions may facilitate TKI binding. Furmonertinib emerges as a potential, cost-effective oral therapeutic alternative for this patient population, especially when standard therapies are not feasible, warranting further prospective investigation.

P1, N=160, Active, not recruiting, ArriVent BioPharma, Inc. | Trial completion date: Dec 2025 --> Dec 2026

P1, N=200, Recruiting, Nuvalent Inc. | N=150 --> 200 | Trial completion date: Mar 2026 --> Feb 2027 | Trial primary completion date: Mar 2026 --> Jan 2027

P2, N=93, Terminated, M.D. Anderson Cancer Center | Trial completion date: Dec 2027 --> Feb 2026 | Active, not recruiting --> Terminated | Trial primary completion date: Dec 2027 --> Feb 2026; <75% participation