Clinical activity of pembrolizumab with or without chemotherapy in advanced pulmonary large-cell and large-cell neuroendocrine carcinomas: a multicenter retrospective cohort study.

BACKGROUND: Immune checkpoint inhibitors (ICI)-based combination strategies have improved the survival outcomes in advanced non-small cell lung cancers; however, data regarding their efficacy remains limited for uncommon histological types, including large-cell carcinoma (LCC) and large-cell neuroendocrine carcinoma (LCNEC). METHODS: We retrospectively analyzed a total of 60 patients with advanced LCC and LCNEC - 37 treatment-naïve and 23 pre-treated - who received pembrolizumab with or without chemotherapy. Treatment and survival outcomes were analyzed. RESULTS: Of the 37 treatment-naïve patients who received first-line pembrolizumab combined with chemotherapy, the 27 patients with LCC had an overall response rate (ORR) of 44.4% (12/27) and a disease control rate (DCR) of 88.9% (24/27); whereas 10 patients with LCNEC had an ORR of 70% (7/10) and DCR of 90% (9/10). The median progression-free survival (mPFS) was 7.0 months (95% confidence intervals [CI]: 2.2-11.8) and median overall survival (mOS) was 24.0 months (95%CI: 0.0-50.1) for first-line pembrolizumab plus chemotherapy of LCC (n = 27), whereas mPFS was 5.5 months (95%CI: 2.3-8.7) and mOS was 13.0 months (95%CI: 11.0-15.0) for first-line pembrolizumab plus chemotherapy of LCNEC (n = 10). Of the 23 pre-treated patients who received subsequent-line pembrolizumab with or without chemotherapy, mPFS was 2.0 months (95% CI: 0.6-3.4) and mOS was 4.5 months (95% CI: 0.0-9.0) for LCC and mPFS was 3.8 months (95% CI: 0.0-7.6) and mOS was not reached for LCNEC. CONCLUSION: Our study provides real-world clinical evidence of the anti-tumor activity of pembrolizumab plus chemotherapy in advanced LCC and LCNEC, indicating that this regimen could serve as a treatment option, particularly as first-line therapy, for improving the survival outcomes of patients with these rare histological subtypes of lung cancer. TRIAL REGISTRATION: NCT05023837(ESPORTA, 27/08/2021).

mTORC2 regulates ribonucleotide reductase to promote DNA replication and gemcitabine resistance in non-small cell lung cancer.

Ribonucleotide reductase (RNR) is the key enzyme that catalyzes the production of deoxyribonucleotides (dNTPs) for DNA replication and it is also essential for cancer cell proliferation. As the RNR inhibitor, Gemcitabine is widely used in cancer therapies, however, resistance limits its therapeutic efficacy and curative potential. Here, we identified that mTORC2 is a main driver of gemcitabine resistance in non-small cell lung cancers (NSCLC). Pharmacological or genetic inhibition of mTORC2 greatly enhanced gemcitabine induced cytotoxicity and DNA damage. Mechanistically, mTORC2 directly interacted and phosphorylated RNR large subunit RRM1 at Ser 631. Ser631 phosphorylation of RRM1 enhanced its interaction with small subunit RRM2 to maintain sufficient RNR enzymatic activity for efficient DNA replication. Targeting mTORC2 retarded DNA replication fork progression and improved therapeutic efficacy of gemcitabine in NSCLC xenograft model in vivo. Thus, these results identified a mechanism through mTORC2 regulating RNR activity and DNA replication, conferring gemcitabine resistance to cancer cells.

A novel ROS1 G2032 K missense mutation mediates lorlatinib resistance in a patient with ROS1-rearranged lung adenocarcinoma but responds to nab-paclitaxel plus pembrolizumab.

INTRODUCTION: ROS1-rearranged non-small cell lung cancer (NSCLC) has demonstrated promising response to lorlatinib; however, no targeted therapy is available after failure of lorlatinib and information on acquired resistance mechanisms mediating lorlatinib resistance among ROS1-rearranged NSCLC patients is limited. We report a ROS1-rearranged NSCLC patient who responded to immunochemotherapy after acquisition of ROS1 G2032K-mediated lorlatinib resistance. METHODS: Next-generation sequencing (NGS) was performed on supraclavicular lymph nodes (SLN) and blood samples obtained from the 53-year old male patient with advanced CD74-ROS1-rearranged NSCLC. In vitro experiments with patient-derived SLN tumor cells and in silico homology modeling were performed to investigate mechanisms of G2032K-mediated inhibitor resistance. RESULTS: NGS analysis revealed the detection of an acquired ROS1 G2032 K after failure from lorlatinib. Homology modeling revealed the conformational change in the inhibitor binding site induced by the ROS1 G2032 K that disrupted lorlatinib binding. In vitro experiments using patient-derived cells bearing concurrent CD74-ROS1-rearrangement and ROS1 G2032 K demonstrated half-maximal inhibitory concentration IC50 of 730.2 nM for lorlatinib, 812.1 nM for entrectinib, and 1546 nM for crizotinib, indicating resistance to these inhibitors. With PD-L1 expression of TPS 30 %, nab-paclitaxel plus pembrolizumab was administered as fifth-line treatment and achieved partial response, with sustained response ongoing for 7 months as of January 31, 2020. CONCLUSION: ROS1 G2032 K is a novel mutation that mediates resistance to lorlatinib. With the lack of targeted therapeutic options after lorlatinib resistance, checkpoint inhibitor plus chemotherapy may be considered as a treatment option in patients with ROS1-rearranged NSCLC.