Comparative efficacy and tolerability of targeted and immunotherapy combined with chemotherapy as first-line treatment for advanced gastric cancer: a Bayesian network meta-analysis

Exploration of radionuclide labeling of a novel scFv-Fc fusion protein targeting CLDN18.2 for tumor diagnosis and treatment

PURPOSE

Claudin 18.2 (CLDN18.2), due to its highly selective expression in tumor cells, has made breakthrough progress in clinical research and is expected to be integrated into routine tumor diagnosis and treatment.

METHODS

In this research, we obtained an scFv-Fc fusion protein (SF106) targeting CLDN18.2 through hybridoma technology. The scFv-Fc fusion protein was labeled with radioactive isotopes (124I and 177Lu) to generate the radio-probes. The targeting and specificity of the radio-probes were tested in cellular models, and its diagnostic and therapeutic potential was further evaluated in tumor-bearing models.

RESULTS

The molecular probes [124I]I-SF106 and [177Lu]Lu-DOTA-SF106 possess high radiochemical purity (RCP, 98.18 ± 0.93 % and 97.05 ± 1.1 %) and exhibit good stability in phosphate buffer saline and 5 % human serum albumin (92.44 ± 4.68 % and 91.03 ± 2.42 % at 120 h). [124I]I-SF106 uptake in cells expressing CLDN18.2 was well targeted and specific, and the dissociation constant was 17.74 nM [124I]I-SF106 micro-PET imaging showed that the maximum standardized uptake value (SUVmax) was significantly higher than CLDN18.2-negative tumors (1.83 ± 0.02 vs. 1.23 ± 0.04, p < 0.001). The maximum uptake was attained in tumors expressing CLDN18.2 at 48 h after injection. [124I]I-SF106 and [177Lu]Lu-DOTA-SF106 dosimetric study showed that the effective dose in humans complies with the medical safety standards required for their clinical application. The results of treatment experiments showed that 3 MBq of [177Lu]Lu-DOTA-SF106 in CLDN18.2-expressing tumor-bearing mice could significantly inhibit tumor growth.

CONCLUSION

These results indicate that radionuclide-labeled scFv-Fc molecular probes ([124I]I-SF106 and [177Lu]Lu-DOTA-SF106) provide a new possibility for the diagnosis and treatment of CLDN18.2-positive cancer patients in clinical practice.

Revolutionizing gastric cancer treatment: The potential of immunotherapy

Gastric cancer, a prevalent malignancy worldwide, ranks sixth in terms of frequency and third in fatality, causing over a million new cases and 769000 annual deaths. Predominant in Eastern Europe and Eastern Asia, risk factors include family medical history, dietary habits, tobacco use, Helicobacter pylori, and Epstein-Barr virus infections. Unfortunately, gastric cancer is often diagnosed at an advanced stage, leading to a grim prognosis, with a 5-year overall survival rate below 5%. Surgical intervention, particularly with D2 Lymphadenectomy, is the mainstay for early-stage cases but offers limited success. For advanced cases, the National Comprehensive Cancer Network recommends chemotherapy, radiation, and targeted therapy. Emerging immunotherapy presents promise, especially for unresectable or metastatic cases, with strategies like immune checkpoint inhi-bitors, tumor vaccines, adoptive immunotherapy, and nonspecific immunomodulators. In this Editorial, with regards to the article "Advances and key focus areas in gastric cancer immunotherapy: A comprehensive scientometric and clinical trial review", we address the advances in the field of immunotherapy in gastric cancer and its future prospects.

Immune checkpoint inhibitors plus chemotherapy for HER2-negative advanced gastric/gastroesophageal junction cancer: a cost-effectiveness analysis

Background

Nivolumab plus chemotherapy (NC) was recently approved as the first-line intervention for human epidermal growth factor receptor 2-negative advanced gastric/gastroesophageal junction cancer (GC/GEJC). Moreover, in the latest KEYNOTE-859 (NCT03675737), pembrolizumab plus chemotherapy (PC) was demonstrated to produce remarkable patient survival outcomes.

Objectives

The clinicians and patients need to assess NC and PC preference for cancer drugs.

Design

The cost-effective analysis.

Methods

In an economic assessment of the United States, United Kingdom, and Chinese healthcare systems using a Markov model simulated patients with GC/GEJC, two treatment decision branches with three health states and a tracked time horizon of 15 years were developed. The overall cost and efficacy outcomes of first-line strategies PC and NC were evaluated at willingness-to-pay (WTP) thresholds of different national, including life-years (LYs), quality-adjusted life-years (QALYs), incremental cost-effectiveness ratios (ICERs), and incremental net-health benefit (INHB). Sensitivity and subgroup analyses were considered.

Results

Given a WTP threshold of $150,000, $60,161, and $37,653 per QALY in the United States, United Kingdom, and China, respectively, both PC and NC achieved QALYs of 1.67 and 1.65 (2.51 and 2.48 LYs), 1.65 and 1.63 (2.48 and 2.45 LYs), and 1.60 and 1.58 (2.40 and 2.37 LYs), with total costs of $242,444 and $232,617, $148,367 and $127,737, and $16,693 and $24,016, respectively. Based on our sensitivity analysis, the programmed death-1 inhibitors cost produced the largest impact on the outcome. In addition, the cost-effectiveness probabilities of PC were 38.3%, 4.1%, and 100% in the three aforementioned countries, respectively.

Conclusion

In the case of the Chinese payers' perspective, PC appeared more dominant as first-line therapy for advanced GC/GEJC patients, whereas NC was preferred in the United States and United Kingdom.