HER2-mutant Non-small Cell Lung Cancer Research Articles

Clinical best practices in interdisciplinary management of human epidermal growth factor receptor 2 antibody-drug conjugates-induced interstitial lung disease/pneumonitis: An expert consensus in China.

Antibody-drug conjugates (ADCs) have demonstrated effectiveness in treating various cancers, particularly exhibiting specificity in targeting human epidermal growth factor receptor 2 (HER2)-positive breast cancer. Recent advancements in phase 3 clinical trials have broadened current understanding of ADCs, especially trastuzumab deruxtecan, in treating other HER2-expressing malignancies. This expansion of knowledge has led to the US Food and Drug Administration's approval of trastuzumab deruxtecan for HER2-positive and HER2-low breast cancer, HER2-positive gastric cancer, and HER2-mutant nonsmall cell lung cancer. Concurrent with the increasing use of ADCs in oncology, there is growing concern among health care professionals regarding the rise in the incidence of interstitial lung disease or pneumonitis (ILD/p), which is associated with anti-HER2 ADC therapy. Studies on anti-HER2 ADCs have reported varying ILD/p mortality rates. Consequently, it is crucial to establish guidelines for the diagnosis and management of ILD/p in patients receiving anti-HER2 ADC therapy. To this end, a panel of Chinese experts was convened to formulate a strategic approach for the identification and management of ILD/p in patients treated with anti-HER2 ADC therapy. This report presents the expert panel's opinions and recommendations, which are intended to guide the management of ILD/p induced by anti-HER2 ADC therapy in clinical practice.

Durable responses to trastuzumab deruxtecan in patients with leptomeningeal metastases from breast cancer with variable HER2 expression.

Emerging data suggest that trastuzumab deruxtecan (T-DXd) is an active treatment for brain metastases from HER2 + breast cancer. We aimed to characterize the activity of T-DXd in the treatment of leptomeningeal metastases (LM) from a range of HER2-altered cancers. We reviewed neuro-oncology clinic records between July 2020 and December 2023 to identify patients who received T-DXd to treat LM. Of 18 patients identified, 6 had HER2 + breast cancer, 8 had HER2-low/negative breast cancer, 2 had HER2 + gastroesophageal cancer, and 2 had HER2-mutant non-small cell lung cancer (NSCLC). 10/18 (56%) patients had cytologically confirmed LM by CSF cytology or circulating tumor cell (CTC) capture. A partial response (PR) on MRI using the EORTC/RANO-LM Revised-Scorecard occurred in 4/6 (67%) patients with HER2 + breast LM, 2/8 (25%) patients with HER2-low/negative breast cancer, and 0/4 (0%) patients with HER2 + gastroesophageal cancer or HER2-mutant NSCLC. Median overall survival after initiating T-DXd was 5.8 months. Survival after initiating T-DXd was numerically longer for HER2 + breast cancer patients compared with HER2-low/negative breast and HER2-altered non-breast cancer patients (13.9 months vs. 5.2 months and 4.6 months, respectively). Landmark analysis showed that patients with radiologic LM response to T-DXd by 2.5 months had longer survival than non-responders (14.2 months vs. 2.6 months, HR 0.18, 95% CI 0.05-0.63, p < 0.05), and landmark analyses at 3.5 and 4.5 months after starting T-DXd showed a similar but nonsignificant trend. T-DXd induces LM responses in a subset of patients, and such responses may be associated with prolongation of survival. Prospective trials are needed to clarify the role of T-DXd in treating LM and which patients are most likely to benefit.

Trastuzumab deruxtecan in HER2-mutant non-small-cell lung cancer: a plain language summary of the DESTINY-Lung01 study.

This is a summary of the publication about the DESTINY-Lung01 study, which was published in the New England Journal of Medicine in September 2021. The DESTINY-Lung01 study includes 181 adults with metastatic non-small-cell lung cancer (NSCLC) that could not be treated with surgery and who have had previous standard anticancer treatment. The publication includes information and results about 91 of the 181 study participants. These 91 participants had HER2-mutant NSCLC. Researchers wanted to learn if the drug trastuzumab deruxtecan (T-DXd) could help treat participants with HER2-mutant NSCLC. At the time of this publication, this study is ongoing. Results from the study showed that 55% of participants responded to treatment with T-DXd. The median length of time participants continued to respond to T-DXd was 9.3months.After receiving T-DXd, 92% of participants had disease control. After receiving T-DXd, half of the participants lived for at least 17.8months. After receiving T-DXd, half of the participants lived for 8.2months before their cancer got worse.During the study, 97% of participants had drug-related adverse events, with nausea being the most common. There were 20% of participants with serious drug-related adverse events. Based on these results, T-DXd could be a treatment option for people with HER2-mutant NSCLC that has been previously treated.Clinical Trial Registration: NCT03505710 (DESTINY-Lung01) (ClinicalTrials.gov).

SHR-A1811 (antibody-drug conjugate) in advanced HER2-mutant non-small cell lung cancer: a multicenter, open-label, phase 1/2 study

A dose-escalation and expansion, phase 1/2 study (ClinicalTrials.gov, NCT04818333) was conducted to assess the novel antibody-drug conjugate SHR-A1811 in pretreated HER2-altered advanced non-small cell lung cancer (NSCLC). Here, we report results from the phase 1 portion. Patients who had previously failed or were intolerant to platinum-based chemotherapy were enrolled and received SHR-A1811 intravenously at doses of 3.2 to 8.0 mg/kg every 3 weeks. Dose escalation followed a Bayesian logistic regression model that included overdose control, with subsequent selection of tolerable levels for dose expansion. Overall, 63 patients were enrolled, including 43 receiving a recommended dose for expansion of 4.8 mg/kg. All patients had HER2-mutant disease. Dose-limiting toxicity occurred in one patient in the 8.0 mg/kg dose cohort. Grade ≥ 3 treatment-related adverse events occurred in 29 (46.0%) patients. One patient in the 6.4 mg/kg cohort died due to interstitial lung disease. As of April 11, 2023, the 4.8 mg/kg cohort showed an objective response rate of 41.9% (95% CI 27.0–57.9), and a disease control rate of 95.3% (95% CI 84.2–99.4). The median duration of response was 13.7 months, with 13 of 18 responses ongoing. The median progression-free survival was 8.4 months (95% CI 7.1–15.0). SHR-A1811 demonstrated favourable safety and clinically meaningful efficacy in pretreated advanced HER2-mutant NSCLC.

First case report of sunvozertinib for the treatment of HER2 exon 20 insertion in lung adenocarcinoma.

Human epidermal growth factor receptor 2 (HER2) is a transmembrane glycoprotein receptor with intracellular tyrosine kinase activity. It is generally considered as a poor prognostic marker. Targeted therapies, such as small molecule tyrosine kinase inhibitors (TKIs), showed limited efficacy in HER2-mutant advanced nonsmall cell lung cancer (NSCLC). In the 2023 National Comprehensive Cancer Network guidelines for NSCLC, antibody-drug conjugate trastuzumab emtansine is recommended for the treatment of HER2-mutant lung cancer. However, this medication is currently not approved in certain regions.So it is necessary to explore alternative treatment options for HER2-mutant NSCLC patients. In our study of a patient with HER2 exon 20 insertion lung adenocarcinoma who had previously failed multiple epidermal growth factor receptor (EGFR)-TKI treatments, we discovered that sunvozertinib could stabilize the patient's condition, achieving a progression-free survival of 87 days. This is a novel finding that may provide new treatment options for HER2 exon 20 insertion patients who have failed TKI therapy.

Exposure-response (ER) analyses of efficacy and safety of trastuzumab deruxtecan (T-DXd) to inform dosing recommendation in HER2-mutant non-small cell lung cancer (NSCLC).

e20545 Background: T-DXd, a novel human epidermal growth factor receptor 2 (HER2) targeting antibody drug conjugate, was evaluated at doses of 5.4 and 6.4 mg/kg every three weeks in Phase 1 or 2 trials in HER2 mutant (HER2m) NSCLC subjects, including Destiny-Lung01 (DL-01) and DL-02 trials1,2. ER analyses of key efficacy and safety endpoints were conducted to support the dosing recommendation of T-DXd in HER2m NSCLC. Methods: Exposure-efficacy (EE) analysis was performed using confirmed objective response (cORR) data from HER2m NSCLC in Phase 1-2 trials (N = 181). The dataset included primary analysis data cut from DL-011 and interim analysis data cut from DL-02. Exposure-safety (ES) analyses of T-DXd were performed, using pooled data from 11 Phase 1-3 trials (N = 1850) across tumor types, including DL-01 and DL-02, for safety endpoints of adverse events (AEs) associated with dose reduction or discontinuation, Grade3+ (G3+) AEs, serious AEs, G3+Anemia, G3+neutropenia, G3+thrombocytopenia, adjudicated any grade interstitial lung disease (ILD), and G3+ ILD. cORR and all safety endpoints, except ILD were analyzed by logistic regression; any grade ILD was analyzed by parametric time-to-event analysis. The T-DXd or DXd exposure metric and numerous patient-specific covariates were tested in the analysis. Results: T-DXd exposure had a positive but shallow relationship with cORR. The predicted cORR varied from 57% (95% credible interval (CrI): [36, 77]) to 65% (95% CrI: [41, 84]) across 5th and 95th percentile of T-DXd exposure respectively. No clinically meaningful difference in cORR was estimated across 5.4 and 6.4 mg/kg doses with predicted cORR values of 53% (95% CrI: [44, 60]) and 55% (95% CrI: [47, 62]) at T-DXd doses of 5.4 mg/kg and 6.4 mg/kg, respectively. ES relationships were consistent with previous T-DXd ES analyses in breast cancer (BC). Model-predicted AE rates were lower (up to 9%) in 5.4 mg/kg compared to the 6.4 mg/kg dose. Model-predicted safety at 5.4 mg/kg dose in HER2m NSCLC was similar to the approved dose of 5.4 mg/kg in BC. Conclusions: The ER analyses showed no clinically meaningful difference in efficacy between 5.4 and 6.4 mg/kg doses of T-DXd; and safety events were lower in 5.4 mg/kg, thus supporting the 5.4 mg/kg recommended dose for HER2m NSCLC. These findings were later confirmed based on primary analysis in DL-022 and support the utility of ER analyses in dosing recommendation. Reference: Li BT et al. N Engl J Med 2022;386:241-51 Goto K et al. J Clin Oncol 41:4852-4863. Clinical trial information: NCT03505710 , NCT04644237 .

HER2 mutations in advanced cervical neuroendocrine carcinoma: implications for trastuzumab deruxtecan therapy.

Recent clinical evidence shows that the antibody-drug conjugate (ADC) trastuzumab deruxtecan (T-DXd) can successfully treat patients with advanced HER2-mutant non-small cell lung cancer (NSCLC). We aimed to characterize HER2 mutations in cervical neuroendocrine carcinoma (NEC) among Taiwanese women to provide the rationale for exploring T-DXd as a tumor-agnostic targeted therapy option. We analyzed 12 archived primary cervical NEC samples from Taiwanese patients. Tumor-rich areas were marked for microdissection on 10 μm unstained sections. DNA was extracted, and HER2 hotspots were sequenced using a targeted panel on the Illumina MiSeq. HER2 missense mutations were identified in 5 of 12 cases (41.7%). Of the 5 cases with mutations, 2 patients (40%) had a single mutation, while 3 patients (60%) had double mutations. We detected 4 substitutions outside the tyrosine kinase domain (non-TKD), which were p.P1170A, p.S305C, p.I655V, and a novel T328K alteration. No mutations were found within the tyrosine kinase domain (TKD). The 41.7% HER2 mutation rate warrants expanded screening and future clinical investigation of the T-DXd targeting HER2 mutations in cervical NEC patients. Overall, this study contributes to the molecular understanding of cervical NEC and lays the groundwork for developing more effective treatment strategies.

Phase 1b trial of anti-HER2 antibody inetetamab and pan-HER inhibitor pyrotinib in HER2-positive advanced lung cancer.

There remains an unmet need for targeted therapies against advanced non-small-cell lung cancer (NSCLC) with HER2 mutations. To improve the antitumor activity of single anti-HER2 agent, this prospective, single-arm clinical trial (NCT05016544) examined the safety profile and efficacy of anti-HER2 antibody inetetamab and pan-HER TKI pyrotinib in HER2-posivite advanced NSCLC patients. Enrolled patients received inetetamab every 3weeks and pyrotinib once per day (pyrotinib, dose-escalation part, 240mg, 320mg; dose-expansion part, 320mg). Primary endpoints were dose-limiting toxicity (DLT) dosage and safety. Secondary endpoints included progression-free survival (PFS), objective response rate (ORR), and disease control rate (DCR). A total of 48 patients were enrolled. During the dose-escalation period, no DLT occurred. Diarrhea was the most commonly reported treatment-related adverse event (TRAE). Grade 3 TRAEs occurred in seven patients. The median PFS (mPFS) was 5.5months [95% confidence interval (CI): 4.4-8.6months]. The confirmed ORR and DCR reached 25% (11/44) and 84.1% (37/44), respectively. Responses were shown in patients with distinct HER2 aberrations. In summary, inetetamab in combination with pyrotinib demonstrated acceptable safety and antitumor activity among patients with advanced HER2-mutant NSCLC.

Abstract 4005: HER2 TKIs enhance the anti-tumor activity of HER2-targeting CAR-T and CAR-NK cells against NSCLC

Abstract Approximately 3% of non-small cell lung cancer (NSCLC) cases harbor ERBB2/HER2 mutations. Notably, the majority of actionable HER2 mutations in NSCLC are in-frame insertions in exon 20. Current HER2-targeting approaches, including antibody-drug conjugates (ADCs) such as trastuzumab deruxtecan, have shown promising response rates. To explore novel strategies for targeting HER2-positive NSCLC, we investigated chimeric antigen receptor (CAR)-based therapies to enhance the anti-tumor activity of immune effector cells. We engineered a series of HER2 CAR constructs utilizing scFvs derived from trastuzumab, pertuzumab, and FRP5, recognizing distinct domains of HER2. These scFvs were integrated into second-generation BB3z (with 4-1BB and CD3z intracellular domains) and third-generation 28BB3z (with CD28, 4-1BB, and CD3z intracellular domains) CAR backbones, which were subsequently transduced into activated T and natural killer (NK) cells to generate CAR-T and CAR-NK cells, respectively. High transduction efficiencies were achieved, with over 80% in CAR-T cells and over 50% in CAR-NK cells. We next evaluated their activity against a panel of NSCLC cell lines expressing varying levels of HER2 in vitro using firefly luciferase assays. All HER2 CAR-T cells demonstrated more than 90% killing against H2170 (HER2 high) and H322 (HER2 medium) at an effector:target (E:T) ratio of 10:1, whereas HER2 CAR-T cells yielded a killing effect of 35% against A549 (HER2 low) cells. HER2-targeting CAR-NK cells also displayed potent cytotoxicity against HER2-expressing NSCLC cells. Moreover, we observed that treatment of HER2 mutant and HER2 amplified NSCLC cells with low doses of HER2 tyrosine kinase inhibitors (TKIs) such as poziotinib enhanced the expression of HER2 on the cell surface. This upregulation resulted in enhanced activation of HER2 CAR-T and CAR-NK cells in coculture experiments as measured by CD107a expression on effector cells. Additionally, treatment with the HER2 TKI poziotinib potentiated the killing activity mediated by HER2 CAR-T and CAR-NK cells. Using a HER2 YVMA duplication patient-derived xenograft (PDX) NSCLC model, we observed that the in vivo combination of poziotinib with HER2 CAR-NK cells exhibited superior anti-tumor activity as compared to poziotinib treatment alone. In conclusion, HER2 CAR-T and CAR-NK cells effectively target HER2-mutant and HER2-positive NSCLC, and their combination with HER2 TKIs enhances vulnerability to HER2-targeting strategies. Citation Format: Yan Yang, Monique B. Nilsson, Alissa Poteete, Junqin He, Qian Huang, John V. Heymach. HER2 TKIs enhance the anti-tumor activity of HER2-targeting CAR-T and CAR-NK cells against NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4005.

A Patient-Centric Trial of Pyrotinib Reveals Clinical Benefit in Lung Cancer.

Pyrotinib has clinical bene-fit and low toxicity in treatment-naive, HER2-mutant non-small cell lung cancer.

Prognostic and predictive implications of plasma ctDNA in guiding first-line targeted therapy for metastatic HER2-mutant non-small cell lung cancer (NSCLC).

9052 Background: Trastuzumab deruxtecan (T-DXd) is the first HER2-targeted drug approved for NSCLC with human epidermal growth factor receptor 2 ( HER2, ERBB2) mutation in the second or later line settings. However, the optimal first-line treatment for these patients remains unclear. Access to rapid tissue sequencing is not always available, thus presenting challenges to first-line drug development. Circulating tumor DNA (ctDNA) analysis has the potential to overcome these obstacles to guide optimal first-line targeted therapy for patients with HER2-mutant NSCLC. Methods: We retrospectively analyzed patients with metastatic HER2-mutant NSCLC who underwent prospective clinical ctDNA sequencing at Memorial Sloan Kettering Cancer Center (MSK) from January 2016 to September 2022. HER2 mutations were identified by next-generation sequencing through MSK-IMPACT, MSK-ACCESS or Resolution ctDx Lung. Results: We identified 64 patients with metastatic HER2-mutant NSCLC who had received at least one line of systematic therapy. The median age was 63 years (range: 23–90), and there were more women (n = 38, 60%), and never-smokers (n = 38, 60%). The activating HER2 mutations included exon 20 insertions (73%), exon 8 (11%), 19 (11%), and 20 SNVs (5%). Plasma ctDNA was tested before initial therapy in 40 patients with a median overall survival (OS) of 28 months (95% CI 21-34), in whom 31 patients (78%) had at least one detectable ctDNA alteration by MSK-ACCESS and ctDx Lung. 55% (17/31) received chemoimmunotherapy with pembrolizumab as the first-line treatment. The median time to treatment discontinuation (TTD) was 6 months (95%CI 5.5-6.9). Additionally, 19% of patients (6/31) received a HER2-targeted antibody-drug conjugates (ADC) as first-line treatment with a median TTD of 6 months (95% CI 2-10), including 5 with T-DM1 and one who received first-line T-DXd treatment with a TTD of 9 months. Patients with baseline ctDNA alterations had significantly shorter OS (hazard ratio (HR), 5.25; 95% CI, 1–24; p = 0.019). Conclusions: Baseline plasma ctDNA has the potential to guide first-line targeted therapy for patients with HER2-mutant NSCLC. As an independent negative prognostic biomarker, detectable ctDNA at baseline would need to be taken into account for patient selection in future studies to avoid underestimating the effects of therapy.

Safety and efficacy of inetetamab in combination with pyrotinib in HER2 mutant patients with non-small cell lung cancer (NSCLC): An open-label, phase Ib trial.

9105 Background: Currently, limited targeted therapies are available for HER2 mutant NSCLC patients. Previous studies have shown the antitumor activity of pyrotinib in advanced NSCLC patients with HER2 mutations. Inetetamab is a recombinant humanized anti-HER2 monoclonal antibody. Whether inetetamab combined with pyrotinib could show manageable safety and more active antitumor activity remains unknown. This study was designed to evaluate the safety and efficacy of inetetamab in combination with pyrotinib in HER2 mutant patients with advanced NSCLC. Methods: This study was an open-label, phase Ib study. The HER2 mutant patients with locally advanced or metastatic NSCLC were assigned to receive inetetamab combined with pyrotinib. The study consisted of dose-escalation part and dose-expansion part. During dose-escalation period, the parallel "3+3" dose-escalation design was used to determine the dose-limiting toxicity (DLT). Inetetamab was administered every 3 weeks (8 mg/kg loading dose for cycle 1, followed by 6 mg/kg in subsequent cycles) with pyrotinib (dose-escalation part, 240mg QD, 320mg QD; dose-expansion part, 320mg QD). Primary endpoint of the study was DLT dosage and safety. The DLT was assessed during the 21-day DLT evaluation period after the first dose. Secondary endpoints included objective response rate (ORR), disease control rate (DCR), progression free survival and overall survival. Results: Between August 6, 2021, and August 25, 2022, 48 patients were enrolled. No DLT occurred during pyrotinib 240mg and 320mg escalation period. Therefore, pyrotinib 320mg was chosen as expansion dose. The most common treatment-related adverse events (TRAEs) were diarrhea (66.7% [2/3] in pyrotinib 240mg group, 95.6% [43/45] in pyrotinib 320mg group), rash (66.7% [2/3] in pyrotinib 240mg group, 22.2% [10/45] in pyrotinib 320mg group) and vomiting (0 in pyrotinib 240mg group, 24.4% [11/45] in pyrotinib 320mg group). TRAEs were generally Grade (G) 1-2. Only 7 patients reported G3 TRAE (1 in pyrotinib 240mg group, 6 in pyrotinib 320mg group). The preliminary efficacy was shown in the table below. The ORR and DCR of group receiving inetetamab with pyrotinib 240mg were 0% and 66.7%, respectively. The ORR and DCR of inetetamab with pyrotinib 320mg group were 36.6% and 85.4% respectively. The relationship between different mutation subtypes or co-mutations and efficacy will be updated during the conference reports. Conclusions: The preliminary data of inetetamab in combination with pyrotinib showed manageable safety and compelling antitumor activity in advanced NSCLC patients harboring HER2 mutations. Clinical trial information: NCT05016544 . [Table: see text]

'Targeting' Improved Outcomes with Antibody-Drug Conjugates in Non-Small Cell Lung Cancer-An Updated Review.

Antibody-Drug conjugates (ADCs) are a relatively new class of drugs with a promise to improve the outcomes in specific cancers. By delivering the cytotoxic agent to tumor cells expressing specific antigens, ADCs achieve a better therapeutic index and more potency. ADCs have been approved for several hematological and solid malignancies, including breast, urothelial and gastric carcinoma. Recently, trastuzumab deruxtecan (TDXd) was the first ADC approved for previously treated metastatic HER2-mutant non-small cell lung cancer (NSCLC). Many promising ADCs are in the pipeline for clinical development in non-small cell lung cancer, including sacituzumab govitecan, patritumab deruxtecan, datopotamab deruxtecan and tusamitamab ravtansine. There is a hope that these drugs would cater to the unmet need of specific patient populations, including patients with currently untargetable mutations. We hope these drugs, e.g., TROP2 targeted ADCs, will also give more options for therapy in NSCLC to improve outcomes for patients. In this comprehensive review, we will be discussing the recent evidence including targets, efficacy and the safety of newer ADC candidates in NSCLC. We will also briefly discuss the specific toxicities, novel biomarkers, overcoming resistance mechanisms, challenges and the way forward, as these new ADCs and combinations find a way into the clinical practice.

Outcome comparison of pyrotinib with current standard of care in the second/third line setting in advanced non-small cell lung cancer patients with HER2 mutation.

Outcome comparison of pyrotinib with current standard of care in the second/third line setting in advanced non-small cell lung cancer patients with HER2 mutation.

Abstract 4019: Preclinical activity of ELVN-002: A potent, selective, and irreversible HER2 and pan-HER2 mutant small molecule inhibitor for the treatment of HER2 driven malignancies

Abstract Mutation or amplification of the human epidermal growth factor receptor 2 (HER2) gene has been identified in numerous solid tumor types, including non-small cell lung cancer (NSCLC), breast, and colorectal cancer. These genetic alterations are believed to confer elevated HER2 activity resulting in oncogenic transformation. In NSCLC, an estimated 3% of patients harbor activating mutations in the HER2 gene. Enhertu (T-DXd), a HER2-specific antibody-drug conjugate was recently approved as an important therapy for this patient population. However, for patients who are not candidates for T-DXd or have discontinued treatment due to an adverse event or disease progression, there exist few therapeutic options. Accordingly, HER2 inhibitors have the potential to provide meaningful therapeutic benefit to these patients. Due to significant structural homology between EGFR and HER2, most investigational small molecule HER2 kinase inhibitors are dual EGFR/HER2 inhibitors and are substantially dose-limited by EGFR-related toxicities in patients. These toxicities likely limit their clinical activity. Currently, tucatinib is the only HER2-selective small molecule inhibitor approved for metastatic breast cancer in combination with trastuzumab and capecitabine. However, it lacks sufficient potency against several of the key clinically relevant mutations, including HER2 YVMA, the most common exon 20 insertion mutation, prevalent in HER2 mutant NSCLC. ELVN-002 is a potent, irreversible inhibitor of HER2 with a &amp;gt;100-fold selectivity over EGFR. ELVN-002 potently inhibits the phosphorylation of HER2 in cell lines endogenously expressing HER2 or in those engineered to express specific clinically relevant HER2 mutants. This activity readily translates into marked anti-proliferative activity against cell lines dependent upon HER2 for their growth and survival. In addition, ELVN-002 is highly selective for HER2 and HER2 mutants versus wild-type EGFR as demonstrated via assessment of both EGFR-driven proliferation and EGFR phosphorylation in cells. Furthermore, ELVN-002 is highly active in mouse models of HER2-driven cancers, including subcutaneous models driven by wild type or mutant HER2. ELVN-002 is also active in an NCI-N87 wild-type HER2 intracranial model. In all models tested, ELVN-002 treatment is well tolerated and resulted in tumor regressions at exposures believed to be clinically achievable. Due to its selectivity and breadth of activity versus the clinically relevant HER2 mutants, ELVN-002 has the potential to be an effective treatment for HER2 mutant NSCLC as well as other HER2 mutant amplified solid tumors, including metastatic HER2 positive breast cancer. Additionally, ELVN-002 could provide a meaningful therapeutic option for patients with CNS metastases. ELVN-002 has been selected for clinical development. Citation Format: Monette Aujay, Amanda J. Broad, Stefan D. Gross, Li Ren, Joseph P. Lyssikatos, Samuel Kintz, Qi Wang, Helen Collins. Preclinical activity of ELVN-002: A potent, selective, and irreversible HER2 and pan-HER2 mutant small molecule inhibitor for the treatment of HER2 driven malignancies. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4019.

Abstract 383: Trastuzumab deruxtecan resistance is associated with reduced responsiveness to topoisomerase inhibitors (payload resistance) but no reduction in sensitivity to HER2 tyrosine kinase inhibitors

Abstract Activating ERBB2 (HER2) mutations occur across multiple malignancies, and although mutational hotpots vary by disease, HER2 mutations most frequently occur in the tyrosine kinase domain. Among lung cancer patients, the most common HER2 mutation is the exon 20 insertion mutations, Y772dupYVMA, which accounts for over 30% of all HER2 mutations in lung cancer. Recent clinical testing of trastuzumab deruxtecan (T-DXd), a HER2 antibody-drug conjugate (ADC), against HER2 mutant non-small cell lung cancer (NSCLC) demonstrated a confirmed objective response of 55%, a median duration of response of 9.3 months, and a median overall survival of 17.8 months, which ultimately led to the recent approval of T-DXd for HER2 mutant NSCLC. Acquired resistance to targeted agents remains a major clinical challenge, and HER2-mutant patients that initially respond to T-DXd will eventually develop progressive disease. Thus, understanding mechanism of T-DXd resistance and identifying targeted agents that remain effective in cells with acquired T-DXd resistance is of great clinical importance. We generated Ba/F3 cells expressing the HER2 YVMA mutation and assessed sensitivity to HER2 targeting agents by Cell Titer Glo assay. HER2 YVMA cells were sensitive to the EGFR/HER2 tyrosine kinase inhibitor (TKI) poziotinib and the HER2 ADC T-DXd. To generate HER2 ADC resistant cells, we cultured Ba/F3 HER2 YVMA cells in T-DXd continuously for 8 weeks at which point cells resumed rapid proliferation. Cell Titer Glo assay confirmed that Ba/F3 HER2 YVMA cells were sensitive to T-DXd with an IC50 of 195 μg/ml, whereas Ba/F3 HER2 YVMA T-DXd-resistant cells had an IC50 of greater than 1000 μg/ml. Notably, T-DXd resistant cells remained highly sensitive to the HER2 TKI poziotinib with an IC50 of 14 nM and 7.5 nM for T-DXd-resistant and parental cells, respectively. Moreover, T-DXd-resistant cells demonstrated reduced sensitivity to the topoisomerase inhibitor topotecan with an IC50 of 200 nM whereas parental cells had an IC50 of 66 nM, suggesting that acquired T-DXd resistance may be mediated by loss of sensitivity to the ADC payload. Collectively, these data demonstrate that HER2 TKIs such as poziotinib may retain anti-tumor cell activity in HER2 mutant tumor cells with acquired resistance to HER2 ADCs. Citation Format: Monique B. Nilsson, Alissa Poteete, Hibiki Udagawa, Xiaoxing Yu, Junqin He, Xiuning Le, John Heymach. Trastuzumab deruxtecan resistance is associated with reduced responsiveness to topoisomerase inhibitors (payload resistance) but no reduction in sensitivity to HER2 tyrosine kinase inhibitors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 383.

Genomic landscape and efficacy of HER2-targeted therapy in patients with HER2-mutant non-small cell lung cancer.

HER2-targeted therapy provides survival benefits to HER2-mutant non-small cell lung cancer (NSCLC). A better understanding of the clinical and genomic characterization of treatment-naïve HER2-positive NSCLC, as well as the efficacy of and resistance to HER2-targeted therapy in HER2-altered NSCLC, could promote further improvement of HER2 targeted therapy. HER2-altered NSCLC patients was retrospectively included and their genomic profiles were performed by next-generation sequencing. The clinical outcomes included overall response rate, disease control rate and progression-free survival. Among 176 treatment-naïve patients with HER2 alterations, 64.8% harbored HER2 mutations with/without HER2 amplification, and 35.2% carried HER2 amplification only. Molecular characterization was correlated with tumor stage that late-stage NSCLC with HER2 oncogenic mutations showed a higher prevalence of TP53 mutations and a higher tumor mutation burden. However, this correlation was not found in patients with HER2 amplification only. Twenty-one patients with HER2 alterations treated with pyrotinib or afatinib were retrospectively enrolled. Pyrotinib yielded a longer median progression-free survival than afatinib (5.9 [95% CI, 3.8-13.0] vs. 4.0 months [95% CI, 1.9-6.3], P = 0.06) in these patients. Analysis of the genomic profiles before and after anti-HER2 targeted therapies identified de novo HER2 copy number gain and G518W mutation, as well as mutations involving DNA damage repair signaling, SWI-SNF complex, and epigenetic regulations as potential resistance mechanisms. HER2-mutant NSCLC had different molecular features from HER2-amplified NSCLC, and its genomic profile was dependent of tumor stage. Pyrotinib had superior therapeutic effects than afatinib in HER2-altered NSCLC, although larger cohorts are warranted to validate it. HER2-dependent and -independent resistance mechanisms to afatinib and pyrotinib were unveiled.

Evolving Treatment Landscape of HER2-mutant Non-Small Cell Lung Cancer: Trastuzumab Deruxtecan and Beyond.

Successful targeting of HER2-activating mutations in DESTINY-Lung02 phase II study has led to the approval of the antibody-drug conjugate (ADC) trastuzumab deruxtecan (T-DXd) as second-line treatment in patients with non-small cell lung cancer (NSCLC). Despite the impressive results, several matters need to be addressed, including the clinical activity of T-DXd in patients with disease in the central nervous system as well as the role of T-DXd in the context of HER2 overexpression. Additionally, data regarding novel agents used to target HER2 continue to accumulate. This review highlights the challenges and unanswered questions that have emerged after the approval of T-DXd in patients with HER2-mutant NSCLC.

Targeting the EGF receptor family in non-small cell lung cancer—increased complexity and future perspectives

Lung cancer remains the leading cause of cancer-associated mortality worldwide, but with the emergence of oncogene targeted therapies, treatment options have tremendously improved. Owing to their biological relevance, members of the ERBB receptor family, including the EGF receptor (EGFR), HER2, HER3 and HER4, are among the best studied oncogenic drivers. Activating EGFR mutations are frequently observed in non-small cell lung cancer (NSCLC), and small molecule tyrosine kinase inhibitors (TKIs) are the established first line treatment option for patients whose tumors bear "typical/classical" EGFR mutations (exon 19 deletions, L858R point mutations). Additionally, new TKIs are rapidly evolving with better efficacy to overcome primary and secondary treatment resistance (e.g., that due to T790M or C797S resistance mutations). Some atypical EGFR mutations, such as the most frequent exon 20 insertions, exhibit relative resistance to earlier generation TKIs through steric hindrance. In this subgroup, newer TKIs, such as mobocertinib and the bi-specific antibody amivantamab have recently been approved, whereas less frequent atypical EGFR mutations remain understudied. In contrast to EGFR, HER2 has long remained a challenging target, but better structural understanding has led to the development of newer generations of TKIs. The recent FDA approval of the antibody-drug conjugate trastuzumab-deruxtecan for pretreated patients with HER2 mutant NSCLC has been an important therapeutic breakthrough. HER3 and HER4 also exert oncogenic potential, and targeted treatment approaches are being developed, particularly for HER3. Overall, strategies to inhibit the oncogenic function of ERBB receptors in NSCLC are currently evolving at an unprecedented pace; therefore, this review summarizes current treatment standards and discusses the outlook for future developments.

Chinese expert consensus on the diagnosis and treatment of HER2-altered non-small cell lung cancer.

Human epidermal growth factor receptor 2 (HER2) possesses tyrosine kinase activity and participates in cell growth, differentiation and migration, and survival. Its alterations, mainly including mutations, amplifications, and overexpression are associated with poor prognosis and are one of the major drivers in non-small cell lung cancer (NSCLC). Several clinical trials had been investigating on the treatments of HER2-altered NSCLC, including conventional chemotherapy, programmed death 1 (PD-1) inhibitors, tyrosine kinase inhibitors (TKIs) and antibody-drug conjugates (ADCs), however, the results were either disappointing or encouraging, but inconsistent. Trastuzumab deruxtecan (T-DXd) was recently approved by the Food and Drug Administration as the first targeted agent for treating HER2-mutant NSCLC. Effective screening of patients is the key to the clinical application of HER2-targeted agents such as TKIs and ADCs. Various testing methods are nowadays available, including polymerase chain reaction (PCR), next-generation sequencing (NGS), fluorescence in situ hybridization (FISH), immunohistochemistry (IHC), etc. Each method has its pros and cons and should be reasonably assigned to appropriate patients for diagnosis and guiding treatment decisions. To help standardize the clinical workflow, our expert group reached a consensus on the clinical management of HER2-altered NSCLC, focusing on the diagnosis and treatment strategies.