Background/Aim: For immune checkpoint inhibitor (ICI)-pretreated patients, docetaxel and ramucirumab (DOC+RAM) combination therapy may be more effective compared to patients not receiving ICI treatment. Patients and Methods: From June 2013 to July 2018, 39 patients with advanced/recurrent non-small cell lung cancer underwent DOC+RAM therapy. We analyzed the efficacy and safety of DOC+RAM therapy based on the presence (pre-ICI+) or absence (pre-ICI-) of ICI pretreatment history. Results: Of the 39 patients treated with DOC+RAM, we identified 18 (46%) pre-ICI+ patients. Overall response rates for DOC+RAM concerning pre-ICI+ and pre-ICI-patients were 38.9% vs. 19.0%, respectively. Median progression-free survival (PFS) was 5.7 vs. 2.3 months [hazard ratio(HR)=0.36; 95% confidence interval (CI)=0.16-0.80]. Adverse events such as fever, myalgia, arthritis, pleural effusion, and pneumonitis tended to be increased in pre-ICI+ patients. Conclusion: Despite increased toxicity concerns, DOC+RAM therapy in pre-ICI+ patients showed a trend for tumor regression improvement and statistically significant prolongation of PFS. Lung cancer is one of the leading causes of mortality worldwide. Immune checkpoint inhibitor (ICI) monotherapy or combination chemotherapy with cytotoxic agents has been developed for patients with advanced non-small cell lung cancer (NSCLC). However, median progression-free survival (PFS) is limited (1, 2). Applying more effective sequential chemotherapy is important for the prolongation of life. Recently, salvage cytotoxic chemotherapy after ICI treatment has been reported to increase antitumor effects (3-6). Moreover, it has been suggested that the efficacy of sequential cytotoxic chemotherapy may improve both the overall response rate (ORR) and PFS, regardless of the efficacy of previous ICI treatment and programmed death-ligand 1 (PD-L1) expression (4). Some studies have reported that activation of the vascular endothelial growth factor (VEGF) and its receptor (VEGFR) inhibitory (VEGF/VEGFR) signal is one of the ICI resistant mechanisms, and that combination therapy of a VEGF/VEGFR inhibitor with ICI had a synergistic and improved antitumor effect (7). It has also been reported that using docetaxel with ramucirumab, a VEGFR inhibitor combination therapy (DOC+RAM) for ICI-treated patients may be more effective than for patients in historical case controls (6). Therefore, we conducted a retrospective comparative study on the efficacy and toxicity of DOC+RAM therapy at our hospital.

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Moving-mask lithography with backside exposure was utilized to generate master male mold for biodegradable polymer microneedle production. The microneedle shape was calculated from the exposure dose, mask geometry, and moving trajectory using a newly developed computer simulation. Two conditions (90 µm aperture with 80 µm diameter of circular movement, and 90 µm aperture with 90 µm diameter of circular movement) were selected to evaluate the moving-mask exposure effectiveness. By changing the moving trajectory, two different sizes of microneedles were obtained from a single-size aperture mask. The fabricated microneedle and calculated microneedle geometry showed good qualitative agreement. The geometrical difference was 2% in basal diameter and 8%-16% in height. Using the master male mold, biodegradable polymer microneedles made of chondroitin sulfate C sodium salt (CSC) were fabricated by casting from a poly-dimethylsiloxane female mold. The shape of the biodegradable CSC microneedles showed good agreement with the master male mold.

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9103 Background: Osimertinib is a standard drug for first-line treatment of patients with advanced non–small cell lung cancer (NSCLC) harboring EGFR mutations (mt). While tumor mutational burden (TMB)-high and co-occurring genetic alterations (alt) have been reported to be negatively associated with the efficacy of other EGFR-TKIs, the impact of co-occurring genetic alt with EGFR major mt on the efficacy of osimertinib remains unclear. Methods: In a multi-institutional genomic screening project (LC-SCRUM-Asia), we have analyzed lung cancer patients for genomic alt by a targeted next-generation sequencing (NGS) system, Oncomine Comprehensive Assay and Genexus/OPA. We retrospectively evaluated the association between the genomic profile and efficacy of first-line osimertinib for EGFR-mutated NSCLC based on the LC-SCRUM-Asia database. Results: Between March 2015 and January 2022, 12,705 NSCLC patients were enrolled in the LC-SCRUM-Asia database, and EGFR mt was detected in 2,232 patients. Of these, 324 patients, including 171 with ex19del (53%) and 153 with L858R (47%), received first-line treatment with osimertinib. The patient characteristics were as follows: median age, 69 years (range 31-97); females, 64%; never-smokers, 57%; adenocarcinoma, 97%; and performance status 0-1, 99%. The frequency of compound EGFR mt and TMB were higher in the L858R (LR) group than in the ex19del (Ex19) group (compound mt (%), 12 vs. 4; mean TMB (mt/Mb), 3.4 vs. 2.5). There were no differences in the frequencies of other co-occurring genetic alt between the two groups. Higher TMB, alt of genes encoding receptor tyrosine kinase (RTK), including FGFR1, RET, MET etc., and amp of cell-cycle related genes were significantly associated with shorter progression-free survival (PFS) in the entire group (median PFS: TMB > 3 vs. ≤3 mt/Mb = 11.4 vs. 17.1 months; p = 0.023; RTK gene alt+ vs. alt- = 9.7 vs. 15.2 months; p = 0.014; cell-cycle gene amp+ vs. amp- = 10.6 vs. 15.6 months, p = 0.001). EGFR subgroup analysis showed that a higher TMB was significantly associated with a shorter PFS in the LR group (> 3 vs. ≤3 mt/Mb = 10.0 vs. 17.1 months, p < 0.001), but not in the Ex19 group. On the other hand, alt of genes encoding RTK and amp of cell-cycle related genes were significantly associated with a shorter PFS in the Ex19 group (RTK gene alt+ vs. alt- = 8.4 vs. 17.8 months, p = 0.008; cell-cycle gene amp+ vs. amp- = 10.6 vs. 17.5 months, p = 0.003), but not in the LR group. Multivariate analysis identified RTK gene alt in the Ex19 group and higher TMB in the LR group as being independently associated with a shorter PFS. Conclusions: First-line osimertinib treatment was less effective in NSCLC patients harboring Ex19 with other RTK gene alt or LR with a higher TMB, indicating that co-occurring genetic alt affecting the efficacy of osimertinib differ between NSCLC patients harboring Ex19 and LR.

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Background: While sotorasib is the first clinically approved small-molecule inhibitor of KRAS G12C in non-small-cell lung cancer (NSCLC), efficacy of sotorasib alone is limited, presumably due to adaptive resistance mechanisms in cancer cells. To expand therapeutic potential of sotorasib, combination strategies need to be developed. In this study, we conducted a large-scale screening to identify novel combination candidates with sotorasib. In addition, molecular mechanisms of synergistic effects were investigated in multiple preclinical models. Methods: To identify novel combination partners of sotorasib, we conducted high-throughput screening using a kinase inhibitor library containing 1,400 chemical compounds. Anti-proliferative and apoptotic effects in vitro were assessed by ATP-based cell viability assay and/or clonogenic assay, and caspase 3/7 assay and/or Annexin V assay, respectively. Synergistic effects were evaluated by calculating the BLISS index and visualized by SynergyFinder Plus. Immunoblotting was performed using antibodies against pCDK1 (Tyr15), pERK, pAkt, MCL1, BIM, PUMA, BCL2, or BCL-xL. In vivo efficacy studies were performed using a KRAS G12C mutant H358 xenograft nude mouse model. Results: Through the large-scale unbiased combination screening of -1,400 kinase inhibitors, we identified a WEE1 inhibitor (AZD1775), a G2/M checkpoint abrogator in clinical-stage development, as a promising combination partner of sotorasib in KRAS G12C mutant NSCLC. The synergistic effects in vitro were broadly observed in multiple KRAS G12C mutant NSCLC cell lines, regardless of single-agent sensitivity to sotrasib or co-occurring oncogenic mutation profiles. The combination treatment upregulated pro-apoptotic protein BIM, leading to apoptosis. In vivo efficacy studies in H358-xenografted models also demonstrated remarkable tumor regression and durable response in mice treated with sotorasib and AZD1775 compared to ones with a single agent alone. Conclusion: We identify AZD1775, a WEE1 inhibitor, as a novel combination candidate, which enhanced the anti-tumor activity of sotorasib both in vitro and in vivo preclinical models. These findings can lead to a novel therapeutic strategy for KRAS G12C mutant NSCLC. Citation Format: Gaku Yamamoto, Kosuke Tanaka, Ryo Kamata, Shunta Mori, Jie Liu, Toyohiro Yamauchi, Yuta Sakae, Akihiro Ohashi, Susumu S. Kobayashi. Targeting WEE1 to improve the therapy of KRAS G12C mutant non-small cell lung cancer. [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 5739.

Background: EGFR exon 20 insertions are detected in approximately 10% of EGFR mutant non-small cell lung cancer (NSCLC). NSCLC with EGFR exon 20 insertions is resistance to conventional epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) such as osimertinib. CLN-081 is a novel EGFR-TKI which shows promising anti-tumor activity for EGFR exon 20 insertions in an ongoing clinical trial. However, previous studies of other EGFR-TKIs prompted us to hypothesize that tumors would acquire resistance to CLN-081 over time. Investigation of the mechanisms of resistance to CLN-081 will provide novel therapeutic strategies for patients with CLN-081-resistant NSCLC. Methods: We first generated Ba/F3 cells stably expressing EGFR exon 20 insertions (Ba/F3-A767_S768insSVD and Ba/F3-Y764_V765insHH) and human patient-derived cells (PDCs), BID007 and BID019 harboring A763_Y764insFQEA and N771_P772insH, respectively. These cells were treated with increasing concentrations of CLN-081 to establish resistant cells. EGFR kinase domain was sequenced for parent Ba/F3 cell and resistant Ba/F3 clones to identify acquired EGFR mutations in resistant clones. PDC cells resistant to CLN-081 were subjected to whole exome sequencing (WES) and RNA sequencing (RNA-Seq) to examine whether resistant cells harbor acquired mutations and/or show changes in gene expression. Results: Sequencing of the EGFR kinase domain revealed the Cys797Ser (C797S) mutations in all resistant clones of Ba/F3-A767_S768insSVD and Ba/F3-Y764_V765insHH cells. WES of resistant PDC cells showed that both BID007 and BID019 cells acquired mutations in KMT2C, a gene involved in histone methylation. In addition, acquired mutations were found in several kinases such as DGKZ, PAK2, and ROCK1. RNA-Seq showed that several genes involved in inflammatory responses and antigen presentation were upregulated in PDC cells resistant to CLN-081. Conclusion: Our preclinical study identified several mechanisms of resistance to CLN-081 including acquired mutations and inflammatory responses. These results will provide new insights into development of a novel strategy to overcome or prevent resistance to CLN-081. Citation Format: Takuma Hayashida, Yosuke Kagawa, Shunta Mori, Liu jie, Yukie Kashima, Kosuke Tanaka, Hibiki Udagawa, Hiroki Izumi, Susumu Kobayashi. Mechanisms of resistance to CLN-081 (TAS6417) in non-small cell lung cancer with EGFR exon 20 insertions [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5355.