1205MO Updated analysis of DESTINY-Gastric02: A phase II single-arm trial of trastuzumab deruxtecan (T-DXd) in western patients (Pts) with HER2-positive (HER2+) unresectable/metastatic gastric/gastroesophageal junction (GEJ) cancer who progressed on or after trastuzumab-containing regimen

HER2-targeted therapies in cancer: a systematic review

Abnormal alterations in human epidermal growth factor receptor 2 (HER2, neu, and erbB2) are associated with the development of many tumors. It is currently a crucial treatment for multiple cancers. Advanced in molecular biology and further exploration of the HER2-mediated pathway have promoted the development of medicine design and combination drug regimens. An increasing number of HER2-targeted drugs including specific monoclonal antibodies, tyrosine kinase inhibitors (TKIs), and antibody-drug conjugates (ADCs) have been approved by the U.S. Food and Drug Administration. The emergence of ADCs, has significantly transformed the treatment landscape for various tumors, such as breast, gastric, and bladder cancer. Classic monoclonal antibodies and novel TKIs have not only demonstrated remarkable efficacy, but also expanded their indications, with ADCs in particular exhibiting profound clinical applications. Moreover the concept of low HER2 expression signifies a breakthrough in HER2-targeted therapy, indicating that an increasing number of tumors and patients will benefit from this approach. This article, provides a comprehensive review of the underlying mechanism of action, representative drugs, corresponding clinical trials, recent advancements, and future research directions pertaining to HER2-targeted therapy.

Pan-Asian adapted ESMO Clinical Practice Guidelines for the diagnosis, treatment and follow-up of patients with gastric cancer

The European Society for Medical Oncology (ESMO) Clinical Practice Guidelines for the diagnosis, treatment and follow-up of patients with gastric cancer (GC), published in late 2022 and the updated ESMO Gastric Cancer Living Guideline published in July 2023, were adapted in August 2023, according to previously established standard methodology, to produce the Pan-Asian adapted (PAGA) ESMO consensus guidelines for the management of Asian patients with GC. The adapted guidelines presented in this manuscript represent the consensus opinions reached by a panel of Asian experts in the treatment of patients with GC representing the oncological societies of China (CSCO), Indonesia (ISHMO), India (ISMPO), Japan (JSMO), Korea (KSMO), Malaysia (MOS), the Philippines (PSMO), Singapore (SSO), Taiwan (TOS) and Thailand (TSCO), coordinated by ESMO and the Japanese Society of Medical Oncology (JSMO). The voting was based on scientific evidence and was independent of the current treatment practices, drug access restrictions and reimbursement decisions in the different Asian regions represented by the 10 oncological societies. The latter are discussed separately in the manuscript. The aim is to provide guidance for the optimisation and harmonisation of the management of patients with GC across the different regions of Asia, drawing on the evidence provided by both Western and Asian trials, whilst respecting the differences in screening practices, molecular profiling and age and stage at presentation. Attention is drawn to the disparity in the drug approvals and reimbursement strategies, between the different regions of Asia.

The Chinese Society of Clinical Oncology (CSCO): Clinical guidelines for the diagnosis and treatment of gastric cancer, 2023

The 2023 update of the Chinese Society of Clinical Oncology (CSCO) Clinical Guidelines for Gastric Cancer focuses on standardizing cancer diagnosis and treatment in China, reflecting the latest advancements in evidence-based medicine, healthcare resource availability, and precision medicine. These updates address the differences in epidemiological characteristics, clinicopathological features, tumor biology, treatment patterns, and drug selections between Eastern and Western gastric cancer patients. Key revisions include a structured template for imaging diagnosis reports, updated standards for molecular marker testing in pathological diagnosis, and an elevated recommendation for neoadjuvant chemotherapy in stage III gastric cancer. For advanced metastatic gastric cancer, the guidelines introduce new recommendations for immunotherapy, anti-angiogenic therapy and targeted drugs, along with updated management strategies for human epidermal growth factor receptor 2 (HER2)-positive and deficient DNA mismatch repair (dMMR)/microsatellite instability-high (MSI-H) patients. Additionally, the guidelines offer detailed screening recommendations for hereditary gastric cancer and an appendix listing drug treatment regimens for various stages of gastric cancer. The 2023 CSCO Clinical Guidelines for Gastric Cancer updates are based on both Chinese and international clinical research and expert consensus to enhance their applicability and relevance in clinical practice, particularly in the heterogeneous healthcare landscape of China, while maintaining a commitment to scientific rigor, impartiality, and timely revisions.

AXL - a new player in resistance to HER2 blockade

HER2 is a driver in solid tumors, mainly breast, oesophageal and gastric cancer, through activation of oncogenic signaling pathways such as PI3K or MAPK. HER2 overexpression associates with aggressive disease and poor prognosis. Despite targeted anti-HER2 therapy has improved outcomes and is the current standard of care, resistance emerge in some patients, requiring additional therapeutic strategies. Several mechanisms, including the upregulation of receptors tyrosine kinases such as AXL, are involved in resistance. AXL signaling leads to cancer cell proliferation, survival, migration, invasion and angiogenesis and correlates with poor prognosis. In addition, AXL overexpression accompanied by a mesenchymal phenotype result in resistance to chemotherapy and targeted therapies. Preclinical studies show that AXL drives anti-HER2 resistance and metastasis through dimerization with HER2 and activation of downstream pathways in breast cancer. Moreover, AXL inhibition restores response to HER2 blockade in vitro and in vivo. Limited data in gastric and oesophageal cancer also support these evidences. Furthermore, AXL shows a strong value as a prognostic and predictive biomarker in HER2+ breast cancer patients, adding a remarkable translational relevance. Therefore, current studies enforce the potential of co-targeting AXL and HER2 to overcome resistance and supports the use of AXL inhibitors in the clinic.

Ramucirumab beyond progression plus TAS-102 in patients with advanced or metastatic esophagogastric adenocarcinoma, after treatment failure on a ramucirumab-based therapy

Based on results of prior trials (TAGS, REGARD, RAINBOW), the combination of ramucirumab beyond progression with TAS-102 (trifluridine/tipiracil) seems to be promising in advanced esophagogastric adenocarcinoma (EGA). In this multicenter, non-randomized, open-label, investigator-initiated pilot trial, ramucirumab-pretreated patients with metastatic EGA received a maximum of 4 cycles of ramucirumab (8 mg/kg i.v. on day 1 and 15, Q2W) plus TAS-102 (35 mg/m2 p.o. bid on day 1-5 and day 8-12; Q2W). Primary endpoint was tolerability and toxicity, defining a positive trial if the SAE rate according to CTCAE 5.0 will increase <30% (up to 55%) compared to historical results from TAGS trial (SAE rate 43%). Secondary endpoints were further evaluation of safety and assessment of efficacy according to tumor response and overall and progression-free survival (OS/PFS). Twenty patients, 20% gastric and 80% GEJ cancers and 55% with ECOG 0 were enrolled. In total, nine SAEs were reported in 25% [95% CI: 8.7-49.1] of the patients, all without relationship to the systemic therapy. The median OS and PFS were 9.1 months [5.4-10.1] and 2.9 months [1.7-4.8], respectively. In addition, a disease control rate of 45% was obtained. The trial showed a favorable safety profile with a numerically lower incidence of SAEs for the combination of ramucirumab with TAS-102 compared to historical TAGS trial. Furthermore, the combination demonstrated efficacy in the beyond progression setting and therefore warrants further evaluation in a randomized trial compared to TAS-102 alone.

Trastuzumab Deruxtecan: A Review in Gastric or Gastro-Oesophageal Junction Adenocarcinoma

Trastuzumab deruxtecan (Enhertu®) is a human epidermal growth factor receptor type 2 (HER2)-directed antibody-drug conjugate that is approved in several countries globally for adults with advanced HER2-positive gastric or gastro-oesophageal junction (GOJ) adenocarcinoma who have received a prior trastuzumab-based regime. In the phase II DESTINY-Gastric01 trial, intravenous trastuzumab deruxtecan was significantly more effective than standard chemotherapy (physician's choice of intravenous irinotecan or paclitaxel) in achieving objective response and improving overall survival in Japanese or South Korean adults with advanced HER2-positive gastric or GOJ adenocarcinoma who had received two or more previous therapies. In the phase II DESTINY-Gastric02 trial, trastuzumab deruxtecan was able to induce durable response in adults from the USA or Europe with unresectable or metastatic HER2-positive gastric or GOJ adenocarcinoma. Trastuzumab deruxtecan was generally tolerable in these patients; the most common adverse events included nausea, neutropenia, fatigue and decreased appetite. Trastuzumab deruxtecan carries regulatory warnings (including boxed warnings in the USA) for interstitial lung disease/pneumonitis and embryo-foetal toxicity. Current evidence indicates that trastuzumab deruxtecan is an effective treatment option, and is generally tolerable, in previously treated adults with advanced HER2-positive gastric or GOJ adenocarcinoma.

Efficacy and Safety of Trastuzumab Deruxtecan and Nivolumab as Third- or Later-Line Treatment for HER2-Positive Advanced Gastric Cancer: A Single-Institution Retrospective Study

PURPOSE

Determination of optimal treatment strategies for HER2-positive advanced gastric cancer (AGC) in randomized trials is necessary despite difficulties in direct comparison between trastuzumab deruxtecan (T-DXd) and nivolumab as third or later-line treatments.

MATERIALS AND METHODS

This single-institution, retrospective study aimed to describe the real-world efficacy and safety of T-DXd and nivolumab as ≥ third line treatments for HER2-positive AGC between March 2016 and May 2022. Overall, 58 patients (median age, 64 years; 69% male) were eligible for the study (T-DXd group, n=20; nivolumab group, n=38).

RESULTS

Most patients exhibited a HER2 3+ status (72%) and presented metastatic disease at diagnosis (66%). The response rates of 41 patients with measurable lesions in the T-DXd and nivolumab groups were 50% and 15%, respectively. The T-DXd and nivolumab groups had a median progression-free survival of 4.8 months (95% confidence interval [CI], 3.3, 7.0) and 2.3 months (95% CI, 1.5, 3.5), median overall survival (OS) of 10.8 months (95% CI, 6.9, 23.8) and 11.7 months (95% CI, 7.6, 17.1), and grade 3 or greater adverse event rates of 50% and 2%, respectively. Overall, 64% patients received subsequent treatment. Among 23 patients who received both regimens, the T-DXd-nivolumab and nivolumab-T-DXd groups had a median OS of 14.0 months (95% CI, 5.0, not reached) and 19.3 months (95% CI, 9.5, 25.1), respectively.

CONCLUSIONS

T-DXd and nivolumab showed distinct efficacy and toxicity profiles as ≥ third line treatments for HER2-positive AGC. Considering the distinct features of each regimen, they may help clinicians personalize optimal treatment approaches for these patients.

Paclitaxel With or Without Cixutumumab as Second-Line Treatment of Metastatic Esophageal or Gastroesophageal Junction Cancer: A Randomized Phase II ECOG-ACRIN Trial

BACKGROUND

Patients with advanced esophageal cancer carry poor prognoses; limited data exist to guide second-line therapy in the metastatic setting. Paclitaxel has been used yet is associated with limited efficacy. There is preclinical evidence of synergy between paclitaxel and cixutumumab, a monoclonal antibody targeting insulin-like growth factor-1 receptor. We conducted a randomized phase II trial of paclitaxel (arm A) versus paclitaxel plus cixutumumab (arm B) in the second-line for patients with metastatic esophageal or gastroesophageal junction (GEJ) cancers.

METHODS

The primary endpoint was progression-free survival (PFS); 87 patients (43 in arm A, 44 in arm B) were treated.

RESULTS

Median PFS was 2.6 months in arm A [90% CL 1.8-3.5] and 2.3 months in arm B [90% 2.0-3.5], P = .86. Stable disease was observed in 29 (33%) patients. Objective response rates for Arms A and B were 12% [90% CI, 5-23%] and 14% [90% CI, 6-25%]. Median overall survival was 6.7 months [90% CL 4.9-9.5] in arm A and 7.2 months [90% CL 4.9-8.1] in arm B, P = 56.

CONCLUSION

The addition of cixutumumab to paclitaxel in second-line therapy of metastatic esophageal/GEJ cancer was well tolerated but did not improve clinical outcomes relative to standard of care (ClinicalTrials.gov Identifier: NCT01142388).

Outcomes of Third-Line Trastuzumab Deruxtecan in a Patient with De Novo Stage 4 HER2-Positive Gastric Adenocarcinoma with Enteroblastic Differentiation: A Case Report

This case report describes the treatment of a patient diagnosed with de novo stage 4 human epidermal growth factor 2 (HER2)-positive gastric adenocarcinoma with enteroblastic differentiation (GAED), a rare and aggressive form of gastric cancer characterized by a tubulopapillary growth pattern and enteroblastic cell lineage markers such as GPC3, SALL4, and alpha fetoprotein. Given the patient's symptomatic, advanced-stage cancer, treatment objectives were focused on effectively deterring disease progression and ameliorating symptoms throughout the anticipated multiple lines of therapy. Subsequent to standard first- and second-line therapies for HER2-positive metastatic GC, third-line treatment using the antibody-drug conjugate trastuzumab deruxtecan (T-DXd) for seven cycles resulted in satisfactory tumor control and well-preserved physical performance and quality of life, with minimal hematologic and pulmonary toxicities. The patient retained acceptable physical performance to receive subsequent lines of therapies, and still showed a tumor marker response to 5L trastuzumab-based chemotherapy. As the tumor was positive for both HER2 and programmed death-ligand 1 (PD-L1) expressions, the selection and sequencing of anti-HER2 and anti-PD-L1 therapies were discussed in relation to the latest U.S. Food and Drug Administration approvals and trial results.

Managing the Risk of Lung Toxicity with Trastuzumab Deruxtecan (T-DXd): A Canadian Perspective

Ongoing advances in precision cancer therapy have increased the number of molecularly targeted and immuno-oncology agents for a variety of cancers, many of which have been associated with a risk of pulmonary complications, among the most concerning being drug-induced interstitial lung disease/pneumonitis (DI-ILD). As the number of patients undergoing treatment with novel anticancer agents continues to grow, DI-ILD is expected to become an increasingly significant clinical challenge. Trastuzumab deruxtecan (T-DXd) is an antibody-drug conjugate targeting human epidermal growth factor receptor 2 that is gaining widespread use in the metastatic breast cancer setting and is undergoing exploration for other oncologic indications. ILD/pneumonitis is an adverse event of special interest associated with T-DXd, which has potentially fatal consequences if left untreated and allowed to progress. When identified in the asymptomatic stage (grade 1), T-DXd-related ILD can be monitored and treated effectively with the possibility of treatment continuation. Delayed diagnosis and/or treatment, however, results in progression to grade 2 or higher toxicity and necessitates immediate and permanent discontinuation of this active agent. Strategies are, therefore, needed to optimize careful monitoring during treatment to ensure patient safety and optimize outcomes. Several guidance documents have been developed regarding strategies for the early identification and management of T-DXd-related ILD, although none have been within the context of the Canadian health care environment. A Canadian multidisciplinary steering committee was, therefore, convened to evaluate existing recommendations and adapt them for application in Canada. A multidisciplinary approach involving collaboration among medical oncologists, radiologists, respirologists, and allied health care professionals is needed to ensure the proactive identification and management of T-DXd-related ILD and DI-ILD associated with other agents with a similar toxicity profile.

Gastric cancer treatment: recent progress and future perspectives

Gastric cancer (GC) is one of the most common malignancies worldwide. Most patients are diagnosed at advanced stages due to the subtle symptoms of earlier disease and the low rate of regular screening. Systemic therapies for GC, including chemotherapy, targeted therapy and immunotherapy, have evolved significantly in the past few years. For resectable GC, perioperative chemotherapy has become the standard treatment. Ongoing investigations are exploring the potential benefits of targeted therapy or immunotherapy in the perioperative or adjuvant setting. For metastatic disease, there have been notable advancements in immunotherapy and biomarker-directed therapies recently. Classification based on molecular biomarkers, such as programmed cell death ligand 1 (PD-L1), microsatellite instability (MSI), and human epidermal growth factor receptor 2 (HER2), provides an opportunity to differentiate patients who may benefit from immunotherapy or targeted therapy. Molecular diagnostic techniques have facilitated the characterization of GC genetic profiles and the identification of new potential molecular targets. This review systematically summarizes the main research progress in systemic treatment for GC, discusses current individualized strategies and presents future perspectives.

Recent Advances in the Systemic Treatment of Localized Gastroesophageal Cancer

The overall survival expectancy of localized gastroesophageal cancer patients still remains under 5 years despite advances in neoadjuvant and adjuvant treatment strategies in recent years. For almost a decade, immunotherapy has been successfully implemented as a first-line treatment for various oncological diseases in advanced stages. In the case of advanced gastroesophageal cancer, 2021 witnessed several approvals of immune checkpoint inhibitor therapies by different authorities. Although it is still a debate whether this treatment should be restricted to a certain subgroup of patients based on biomarker selection, immunotherapy agents are making remarkable steps in resectable settings as well. The Checkmate-577 study demonstrated significant benefits of nivolumab as an adjuvant treatment for resectable esophageal and gastroesophageal junction tumors and thereby obtained approvals both from U.S. American and European authorities. First results of further potential practice-changing clinical trials are expected in 2023, which might change the treatment armamentarium for resectable gastroesophageal cancers significantly. This review aims to demonstrate the advances of immunotherapy and targeted therapies in treatment of localized gastric, gastroesophageal junction and esophageal tumors and gives a short summary on promising ongoing clinical trials.

Incidence of antibody-drug conjugates-related pneumonitis in patients with solid tumors: A systematic review and meta-analysis

BACKGROUND

Antibody-drug conjugates (ADCs) have demonstrated significant efficacy in treating solid tumors. However, the occurrence of ADC drug-associated pneumonitis can limit the use of ADCs or have severe consequences, and we know comparatively little about this.

METHODS

PubMed, EMBASE, and the Cochrane library were exhaustively searched for articles and conference abstracts published before September 30, 2022. Two authors independently extracted data from the included studies. A random-effects model was used to conduct a meta-analysis of the relevant outcomes. Forest plots reflected the incidence rates from each study, and binomial methods were used to calculate the 95 % confidence interval.

RESULTS

This meta-analysis included 7732 patients from 39 studies and evaluated the incidence of ADCs drug-associated pneumonitis which have received market approval for the treatment of solid tumors. The total incidence of solid tumors for all-grade pneumonitis was 5.86 % (95 % CI, 3.54-8.66 %) and for grade ≥3 was 0.68 % (95 % CI, 0.18-1.38 %). The incidence of all-grade pneumonitis was 5.08 % (95 % CI, 2.76-7.96 %) and for grade ≥3 was 0.57 % (95 % CI, 0.10-1.29 %) with ADC monotherapy. The incidence of all-grade and grade ≥3 pneumonitis in trastuzumab deruxtecan (T-DXd) was 13.58 % (95 % CI, 9.43-18.29 %) and 2.19 % (95 % CI, 0.94-3.81 %), respectively, the highest in ADC therapy. Total incidence of all-grade pneumonitis was 10.58 % (95 % CI, 4.34-18.81 %) and for grade ≥3 pneumonitis was 1.29 % (95 % CI, 0.22-2.92 %) with ADC combination therapy. The incidence of pneumonitis was higher with combination therapy than with monotherapy in both all-grade and grade ≥3 groups, but there was no statistical significance (P = .138 and P = .281, respectively). The incidence of ADC-associated pneumonitis in non-small cell lung cancer (NSCLC) was 22.18 % (95 % CI, 2.14-52.61 %), the highest among solid tumors. The 11 included studies reported 21 pneumonitis-related deaths.

CONCLUSIONS

Our findings will assist clinicians in choosing the optimal therapeutic options for patients with solid tumors treated with ADCs.

The evolving therapeutic landscape of trastuzumab-drug conjugates: Future perspectives beyond HER2-positive breast cancer

A novel class of drugs, antibody-drug conjugates (ADCs), are now rapidly emerging as highly effective treatments for solid tumours. ADCs conjugate conventional chemotherapeutics with highly selective targeted monoclonal antibodies. Anti-HER2 therapies selectively target cancer cells expressing human epidermal growth factor receptor 2 (HER2), among them trastuzumab has been the first HER2-targeting monoclonal antibody to achieve successful results that made it the backbone of anti-HER2 therapies. Trastuzumab drug conjugates (T-DCs), use trastuzumab as a selective antibody to lead cytotoxic drugs inside cancer cells. Trastuzumab-emtansine (T-DM1) and trastuzumab-deruxtecan (T-Dxd) are the two approved T-DCs. T-Dxd along with other five T-DCs represents "second generation ADCs" that has been firstly tested in HER2 positive breast cancer (BC) and then in HER2-low BC and other cancers showing promising results thanks to extraordinary and innovative pharmacokinetic and pharmacodynamic characteristics. The evidence generated so far are establishing them as a completely new class of agents effective in solid cancer treatments but also warrants physicians against unconventional toxicity profiles. The role of T-DCs in HER2-positive BC has been largely reviewed, while in this review, we provided for the first time in literature an overview of trastuzumab drug conjugates (T-DCs) approved and/or in clinical development with a specific focus on their efficacy and safety profile in HER2-low BC and other solid tumours different from BC. We started by analysing T-DCs biological characteristics that underly the differences in T-DCs pharmacodynamics and safety profile, then presented the main evidence on the activity and efficacy of these emerging T-DCs in HER2-low BC and other HER2 overexpressing and/or mutated solid tumours and lastly, we provided an overview of the complex and still evolving scenario in which these compounds should be allocated. A specific focus on possible combination strategies with other drugs such as immunotherapy, chemotherapy and target therapy, to increase T-DCs activity and eventually overcome future upcoming resistance mechanisms, are here also critically reviewed.