Rationale and Design of a Phase II Trial of Combined Serplulimab and Chemotherapy in Patients with Histologically Transformed Small Cell Lung Cancer: a Prospective, Single-arm and Multicentre Study.

AIMS: Transformed small cell lung cancer (T-SCLC) is a highly aggressive clinical disease with a notably poor prognosis. It most often arises from epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) following treatment. To date, no standard treatment has been established for T-SCLC. Platinum-etoposide was the most commonly used regimen, but progression-free survival remains unsatisfactory. Therefore, there is an urgent unmet need to develop novel and effective strategies for this population. Our study, a multicentre, open-label, single-arm phase II clinical trial (NCT05957510), aims to evaluate the efficacy and safety of serplulimab plus chemotherapy in untreated T-SCLC patients after histological transformation. MATERIALS AND METHODS: In total, 36 eligible participants experiencing SCLC transformation from EGFR-mutant NSCLC will be enrolled to receive combination therapy of serplulimab, etoposide and carboplatin for four to six cycles, followed by maintenance therapy with serplulimab for up to 2 years. The primary endpoint is progression-free survival; secondary endpoints include objective response rate, overall survival and safety. RESULTS: Enrolment started in July 2023 and is ongoing, with an estimated completion date of December 2025. CONCLUSIONS: This study aims to provide valuable insights into the efficacy and safety of combining serplulimab with chemotherapy for treating patients with T-SCLC originating from EGFR-mutant NSCLC.

Exon-18-EGFR Mutated Transformed Small-Cell Lung Cancer: A Case Report and Literature Review.

Small-cell lung cancer (SCLC) transformation from EGFR mutant adenocarcinoma is a rare entity that is considered to be a new phenotype of SCLC. While transformation from adenocarcinoma (ADC) with EGFR exon 19 deletions and exon 21 L858R point mutations has been described, to our knowledge, no cases of transformation to SCLC from exon-18-mutated ADC have been reported. We reported a clinical case of a patient with exon-18-EGFR-transformed SCLC, and we performed a systematic review of the literature.

Liquid Biopsy for Small Cell Lung Cancer either De Novo or Transformed: Systematic Review of Different Applications and Meta-Analysis.

BACKGROUND: The potential added value of liquid biopsy (LB) is not well determined in the case of small cell lung cancer (SCLC), an aggressive tumor that can occur either de novo or from the histologic transformation of non-small cell lung cancer (NSCLC). METHODS: A systematic review of studies adopting LB in patients with SCLC have been performed to assess the clinical utility of circulating tumor DNA (ctDNA) or circulating tumor cells (CTCs). RESULTS: After a screening of 728 records, 62 studies (32 evaluating CTCs, 27 ctDNA, and 3 both) met predetermined eligibility criteria. Only four studies evaluated LB in the diagnostic setting for SCLC, while its prognostic significance was evaluated in 38 studies and prominently supported by both ctDNA and CTCs. A meta-analysis of 11 studies as for CTCs enumeration showed an HR for overall survival of 2.63 (1.71-4.05), with a potential publication bias. The feasibility of tumor genomic profiling and the predictive role of LB in terms of response/resistance to chemotherapy was assessed in 11 and 24 studies, respectively, with greater consistency for those regarding ctDNA. Intriguingly, several case reports suggest that LB can indirectly capture the transition to SCLC in NSCLC treated with EGFR tyrosine kinase inhibitors. CONCLUSIONS: While dedicated trials are needed, LB holds potential clinical roles in both de novo and transformed SCLC. CtDNA analysis appears the most valuable and practicable tool for both disease monitoring and genomic profiling.

Case report: EGFR-mutant lung adenocarcinoma with the TP53 and RB1 mutations showed resistance to TKI therapy.

Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are a standard treatment for patients with advanced non-small-cell lung cancer (NSCLC) harboring classic EGFR mutations. However, resistance to TKIs remains a major clinical challenge. The transformation from adenocarcinoma to small-cell lung cancer (SCLC) is a rare resistance mechanism to EGFR-TKIs. In this article, we report on 2 lung adenocarcinoma patients with EGFR mutations who developed EGFR-TKI resistance. In case one, the patient was initially diagnosed as lung adenocarcinoma with EGFR L858R, RB1 R445*, and TP53 Y205C mutations. EGFR-TKI failed to bring satisfactory curative effect with the emergence of EGFR T790M mutation and MET amplification and finally passed away. In case two, the patient was diagnosed with lung cancer harboring EGFR L747 and TP53 R342* mutations, and EGFR-TKIs brought a progression-free survival for nine months. However, EGFR-TKI resistance was acquired, and adenocarcinoma transformed into a complex of neuroendocrine carcinoma, SCLC, and lung adenocarcinoma, with the emergence of the EGFR L747, TP53 R342*, and RB1 mutations. Follow-up treatments failed to prevent tumor progression, and the patient died These 2 cases expand our understanding of EGFR-TKI resistance, SCLC transformation, and highlight the importance of histopathology and molecular characteristics for therapeutic strategies for transformed SCLC patients.