Wild-type Epidermal Growth Factor Receptor Research Articles

Abstract 5477: Compound A, a fourth-generation allosteric inhibitor, a potent and highly selective EGFR with L858R activating and C797S resistance mutations for the treatment of NSCLC

Abstract The L858R activating mutation in Epidermal Growth Factor Receptor (EGFR) accounts for approximately 40% of EGFR-mutant non-small cell lung cancer (NSCLC). These patients receive targeted therapy targeting EGFR mutation. To date all approved EGFR tyrosine kinase inhibitors (TKIs) are ATP competitive inhibitors, inevitably lead to drug resistance and to disease progress. Osimertinib is a third-generation EGFR TKI that selectively inhibits both EGFR TKI-sensitizing (L858R) mutation and T790M mutation that confers acquired resistance to first- and second-generation EGFR-TKIs. The patients develop secondary resistance L858R/C797S and L858R/T790M/C797S to this treatment in some cases. There have been strong unmet needs for specific therapies targeting C797S resistance mutations. Additionally, toxicities caused by inhibition of wild-type (WT) EGFR are frequently reported with the first-generation inhibitors (e.g. Gefitinib and Erlotinib). Our Compound A is a highly mutant-selective fourth-generation allosteric inhibitor that targets L858 activating mutations and without affecting EGFR WT that compares favorably with all ATP competitive inhibitors, indicating that it might avoid potential toxicities from targeting EGFR WT. Compound A has a single-digit nanomolar potency against L858R activating mutation and those harboring T790M and C797S resistance mutations. Oral administration of Compound A to tumor-bearing mice showed significant antitumor activity as a single-agent at well-tolerated doses via inhibiting EGFR pathway in the engineered osimertinib-resistance EGFRL858R/T790M/C797S and EGFRL858R/C797S CDX models. Furthermore, Compound A demonstrated excellent efficacy in EGFRL858R/T790M CDX model as a single-agent. Collectively, Compound A has a robust potency against L858R activating mutations including T790M, C797S, and T790M/C797S that cause acquired resistance to ATP competitive EGFR TKIs in vitro and in vivo. Based on the preclinical data, Compound A is a potent, orally available, and mutant-selective fourth-generation allosteric inhibitor of EGFR with L858R activating mutations for the treatment of NSCLC, suggesting that it might have the potential to demonstrate activity in the first line and resistance settings as a single agent. The pre-clinical data described here supports the clinical development of Compound A in NSCLC patients with L858R activating mutations of EGFR. Citation Format: Yeji Byeon, Seung Hee Jung, Daseul Yoon, Seock Yong Kang, Jiyeon Park, Hyeim Jo, Seong-Il Choi, Somyi Park, Seung-chul Lee, Yang Hun Tae, Tae Min Kim, Sung-Yup Cho, Soyeon Kim, Donghyun Ko, Dong-Kyu Kim, Dong-Wan Kim. Compound A, a fourth-generation allosteric inhibitor, a potent and highly selective EGFR with L858R activating and C797S resistance mutations for the treatment of NSCLC [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 5477.

Abstract 3332: LNG-451 is a potent, CNS-penetrant, wild-type EGFR sparing inhibitor of EGFR exon 20 insertion mutations

Abstract Exon 20 insertion mutations (Ex20ins) are the third most common type of EGFR oncogenic mutation in lung cancer patients. While several small molecules have been approved (mobocertinib) or are in clinical development (e.g. CLN-081, BDTX-189) none have demonstrated meaningful CNS activity and they can be associated with treatment-limiting adverse events, including wild-type (WT) EGFR-mediated toxicities. LNG-451 is a CNS-penetrant, wild-type EGFR-sparing, covalent inhibitor of EGFR Ex20ins. In cell viability assays dependent on five EGFR Ex20ins mutations, LNG-451 was a potent inhibitor (IC50 7 - 78 nM) including the three most prevalent insertions (V769_D770insASV IC50 = 78 nM, D770_N771insSVD IC50 = 53 nM, H773_V774insNPH IC50 = 75 nM). LNG-451 had low potency in WT EGFR dependent cell assays (WT EGFR Ba/F3 IC50=1,960 nM, cell panel IC50 = 1630 nM). LNG-451 was 21-fold selective for its least potent Ex20ins (V769_D770insASV) relative to WT EGFR. LNG-451 potently inhibited cells dependent on EGFR L861Q (IC50 = 6 nM), EGFR G719S (IC50 = 8 nM), and EGFR G719S/T263P (IC50 = 11 nM). LNG-451 is a highly selective kinase inhibitor (1 μM LNG-451, >90% inhibition for 7 of 409 WT kinases) with screening hits having a similarly positioned cysteine as EGFR. In a Ba/F3 cell-derived xenograft model harboring an EGFR V769_D770insASV exon 20 insertion mutation (EGFR V769_D770insASV CDX), 10 and 50 mg/kg LNG-451 QD PO dosing for 15 days was well-tolerated and resulted in tumor growth inhibition (TGI) of 75.7% and 105.4%, respectively. LNG-451 was efficacious and well-tolerated in the EGFR Ex20ins HuPrime® LU0387 H773-V774insNPH patient-derived xenograft tumor model: 10 mg/kg LNG-451 QD, 67% TGI; 50 mg/kg LNG-451 QD, 91% tumor regression. LNG-451 was highly active in the intracranial PC9-luc xenograft mouse model. In a single dose PK/PD study using the EGFR V769_D770insASV CDX, similar LNG-451 concentrations were observed in tumor, large intestine, and skin tissues (e.g. 50 mg/kg LNG-451 3h post dose: tumor, 8387 ng/mL; large intestine tissue, 14483 ng/mL; skin, 4623 ng/mL). LNG-451 potently suppressed EGFR phosphorylation in tumor tissue (e.g. 99%, 3 h post 50 mg/kg dose) but had minimal-to modest suppression of phospho-EGFR in large intestine tissue (e.g. 4.2%, 3h post 50 mg/kg dose) and skin tissue (e.g 1.9%, 3h post 50 mg/kg dose). Taken together, LNG-451 is a wild-type EGFR-sparing, CNS-penetrant EGFR Ex20ins inhibitor that is expected to provide strong anti-tumor efficacy for patients with advanced/metastatic solid cancers harboring oncogenic EGFR exon 20 insertions with reduced WT EGFR-driven toxicities. Citation Format: Brion W. Murray, Anjali Pandey, Bruce Roth, Tracy Saxton, Daniel J. Estes, Himanshu Agrawal, Santosh Vishwakarma, Gurulingappa Hallur, Ishtiyaque Ahmad, Ravi Trivedi, Helen Jenkins, Paul G. Pearson. LNG-451 is a potent, CNS-penetrant, wild-type EGFR sparing inhibitor of EGFR exon 20 insertion mutations [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 3332.

Abstract 3261: LNG-451, a potent inhibitor of EGFR exon 20 insertion mutations with high CNS exposure

Abstract Exon 20 insertion mutations (Ex20ins) are the 3rd most common type of EGFR oncogenic mutation in lung cancer patients and are often associated with brain metastases. While several small molecules have been approved (mobocertinib) or are in clinical development (e.g. CLN-081, BDTX-189) none have demonstrated meaningful CNS activity and they can be associated with treatment-limiting adverse events, including wild-type (WT) EGFR-mediated toxicities. LNG-451 is a potent covalent inhibitor of EGFR Ex20ins (IC50 7 - 78 nM) and other EGFR oncogenic mutations (e.g L858R IC50 = 3 nM, exon 19 deletion IC50 = 24 nM) while being selective against WT EGFR (IC50 = 1630 nM). LNG-451 causes tumor regression in both cell line-derived and patient-derived EGFR Ex20ins-dependent xenograft tumor models. In a rat CNS PK model, a single oral dose of 30 mg/kg LNG-451 achieved high exposures in plasma (AUC0 - 8h = 9771 ng•h/mL) and brain (AUC0 - 8h = 10,041 ng•h/g). In a rat steady-state CNS PK model, unbound partition coefficient for LNG-451 was determined to be Kpu,u = 0.66. To evaluate the potential for LNG-451 to treat metastatic brain disease driven by EGFR mutations, an intracranial PC9-luc xenograft mouse model harboring an EGFR exon 19 deletion mutation was used (LNG-451 cellular EGFR Del19 IC50 = 10.6 nM). LNG-451 had dose-dependent exposures in the plasma and brain with both high mean brain exposure (e.g 1074 ng/g with 25 mg/kg LNG-451) and high mean brain to plasma ratios (e.g. 0.451 for 25 mg/kg LNG-451). LNG-451 treatments were well-tolerated and produced significant anti-tumor activities with 99.5% (2.5 mg/kg LNG-451) and 99.9% (25 mg/kg LNG-451) reductions in total bioluminescence signal (BLI) and regression of tumor BLI (2.5 mg/kg LNG-451 28.8% regression; 25 mg/kg LNG-451, 80.3% regression). An ex vivo imaging analysis of the brain and spinal cords from all animals at the end of the study showed a dose-dependent decrease in the bioluminescent signal in both brain and spinal cords from mice treated with LNG-451 relative to the vehicle control animals. Taken together, LNG-451 is a CNS-penetrant, wild-type EGFR-sparing, EGFR Ex20ins inhibitor that is expected to provide strong anti-tumor efficacy for patients with advanced/metastatic solid cancers harboring oncogenic EGFR exon 20 insertions with reduced WT EGFR driven toxicities. Citation Format: Paul G. Pearson, Anjali Pandey, Bruce Roth, Tracy Saxton, Daniel J. Estes, Ravi Trivedi, Himanshu Agrawal, Gurulingappa Hallur, Ishtiyaque Ahmad, Helen Jenkins, Brion W. Murray. LNG-451, a potent inhibitor of EGFR exon 20 insertion mutations with high CNS exposure [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 3261.

Abstract CT184: Emerging evidence of activity of BLU-945 in patients with advanced EGFR-mutant NSCLC utilizing circulating tumor DNA (ctDNA) in the phase 1/2 SYMPHONY study

Abstract Background: Despite recent advances in the treatment of EGFR-mutant (EGFRm) non-small cell lung cancer (NSCLC), most patients treated with third-generation (3G) EGFR tyrosine kinase inhibitors (TKIs), such as osimertinib, experience disease progression. The most common on-target EGFR resistance mutation is at the EGFR C797 residue (i.e., C797S), which prevents covalent binding to 3G EGFR TKIs. While 3G TKIs are effective in patients with EGFR activating and T790M mutations (commonly seen post-progression after first-/second-generation TKIs), there are no targeted therapies approved after their failure. BLU-945 is an investigational, reversible, and selective next-generation EGFR TKI intended for use as a single agent or in combination with other agents to suppress activating and on-target resistance EGFR mutants, including T790M and C797S, while sparing wildtype (wt) EGFR. BLU-945 has shown in vivo antitumor activity in 3G EGFR TKI-naïve as well as resistant NSCLC patient-derived xenograft models with EGFR T790M and C797S mutations. Based on this, we started SYMPHONY (NCT04862780), a phase 1/2 study in patients with metastatic EGFRm NSCLC, to determine the maximum tolerated dose and/or the recommended phase 2 dose (RP2D); and to assess the safety, pharmacokinetics (PK), and antitumor activity of BLU-945. Methods: In the ongoing phase 1 dose-escalation part of the study, patients aged ≥18 years with metastatic EGFRm NSCLC previously treated with ≥1 EGFR TKI (Eastern Cooperative Oncology Group performance status of 0-2) received BLU-945 once daily (QD) on a 28-day cycle following a Bayesian Optimal Interval escalation design. Adverse events (AEs), dose-limiting toxicities (DLTs), PK, ctDNA (in real-time using FoundationOne Liquid panel), and radiographic antitumor activity (by RECIST 1.1 criteria) were assessed in the first 4 treatment cohorts. Results: As of the January 7, 2022, data cut, 18 patients have been treated with BLU-945 at 25-200 mg QD. Of these, 14 (77.8%) patients had received ≥2 lines of prior systemic anticancer therapy in the metastatic setting. There were no DLTs, and most AEs were low grade. Treatment-related AEs (all Grade 1) occurred in 8 (44.4%) patients with the most common being nausea (n=3). EGFR mutation allele fraction assessment by ctDNA at C1D1 and C1D15 showed that tumors were heterogeneous at baseline. At doses of 50 mg QD and higher, reductions in EGFR resistance mutation allele fraction were seen in all patients (n=3) with EGFR C797S (n=2) and/or T790M (n=3) resistance mutations, with a median 48% reduction of these mutations. 50% of patients remain on treatment and dose escalation continues to determine the RP2D. Conclusion: As of the data cut, BLU-945 was generally well tolerated in heavily pre-treated patients with EGFRm NSCLC. There was also early evidence of a reduction in EGFR mutation allele fractions by ctDNA. Citation Format: Elaine Shum, Yasir Elamin, Karen L. Reckamp, Zofia Piotrowska, Julia Rotow, Daniel S. Tan, Koichi Goto, Jagan Parepally, Faris Albayya, Melinda Louie-Gao, Renata Sawtell, Alena Zalutskaya, David Spigel. Emerging evidence of activity of BLU-945 in patients with advanced EGFR-mutant NSCLC utilizing circulating tumor DNA (ctDNA) in the phase 1/2 SYMPHONY study [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 CT184.

Abstract 3259: TAS3351 is a 4th-generation EGFR-TKI overcoming T790M and C797S-mediated resistance in NSCLC with EGFR common mutations

Abstract Background: Common mutations (exon 19 deletion; ex19del or L858R point mutation; L858R) of the epidermal growth factor receptor (EGFR) are found in patients with non-small cell lung cancer (NSCLC) and are sensitive to EGFR-tyrosine kinase inhibitors (TKIs), including osimertinib, a third-generation, irreversible EGFR-TKI. Although osimertinib is widely utilized as the standard of care in first-line therapy of NSCLC, resistance inevitably occurs during the treatment. Among EGFR-dependent/on-target resistant mechanisms of osimertinib, the C797S mutation is reported to emerge as the most frequent alteration. The cysteine residue at position 797 of EGFR is covalently bound with osimertinib, and its alteration to serine causes an inability to form a covalent bond, making osimertinib resistant to NSCLC with a C797S mutation. While first-generation, reversible EGFR-TKIs (gefitinib and erlotinib) might be effective for patients with C797S mutation, the T790M mutation is reported to emerge in almost half of patients with EGFR common mutations during treatment with first-generation EGFR-TKIs. Here, we report TAS3351 as a novel, next-generation EGFR-TKI designed to overcome C797S and T790M-mediated resistance in NSCLC patients. Methods: The inhibitory potency of TAS3351 on cellular phospho-EGFR was analyzed by In-cell western assay. In addition, inhibition of cell viability in Ba/F3 cells transformed by human wild type or mutated EGFR, as well as in human NSCLC cell lines whose EGFR harbors common mutations, was tested. Anti-tumor activity of TAS3351 was evaluated in NIH/3T3-EGFR allograft models and human NSCLC xenograft models. Results: TAS3351 exhibited almost comparable inhibitory potency against cellular phosphorylation of EGFR harboring ex19del or L858R with or without C797S and/or T790M while sparing wild type EGFR activity. TAS3351 also showed similar trends in the cell viability assay for Ba/F3-EGFR cells and human NSCLC cell lines. Finally, TAS3351 demonstrated favorable anti-tumor activity in NIH/3T3 allografts transformed by human EGFR harboring ex19del/C797S/T790M. Conclusion: TAS3351 is a fourth-generation EGFR-TKI overcoming T790M and C797S-mediated resistance in NSCLC with common mutations. The present results support the clinical development of TAS3351 as monotherapy in NSCLC patients with EGFR mutations harboring C797S and/or T790M EGFR-TKI resistance mutations. Citation Format: Hidefumi Kasuga, Yuki Kataoka, Fuyuki Yamamoto, Takashi Mizutani, Shingo Tsuji, Sakiho Tanaka, Shinji Mizuarai. TAS3351 is a 4th-generation EGFR-TKI overcoming T790M and C797S-mediated resistance in NSCLC with EGFR common mutations [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 3259.

Abstract 2691: Expression pattern and prognostic significance of HER family members and EGFRvIII in pancreatic cancer

Abstract Pancreatic cancer is one of the most aggressive, heterogeneous, and fatal types of human cancers. There is urgent need for discovery of biomarkers of prognostic significance, predictive value and as well as therapeutic targets in patients with pancreatic cancer. In this study, we examined the relative expression and prognostic significance of all HER family members and the type III EGFR mutant (EGFRvIII) in patients with pancreatic ductal adenocarcinoma (PDC). The expression levels of wild-type EGFR (wtEGFR), HER2, HER3, HER4 and EGFRvIII were determined in tumor specimens from 43 patients by immunohistochemistry using antibodies DAK-H1-WT, Neu 3B5, SP71, HFR1 and NBP2-50599 respectively. The staining was scored based on the percentage of positive tumor cells, the intensity (i.e. strong 3+, moderate 2+, weak 1+) and the cellular location of immunostaining (i.e. membranous, cytoplasmic or nuclear). The association between the expression level of the biomarkers and patient overall survival was evaluated using Chi-squared, Kaplan-Meier survival curves and log rank test. At cut-off value of above 5%, we found weak to moderate expression of wtEGFR, HER2, HER3, HER4 and EGFRvIII in 4.7%, 14%, 14%, 20.9% and 2.3% of the cases examined respectively. The cellular location of wtEGFR and HER2 was found to be predominantly cytoplasmic, HER-3 membranous and cytoplasmic whereas HER4 expression was found to be mainly nuclear. There was no statistically significant association between the expression level of these markers and patient overall survival. The expression levels of the above biomarkers were also evaluated in tissue microarrays (TMAs) from 40 cases of pancreatic ductal adenocarcinoma. Interestingly, at the same cut-off value, 62.5%, 75%, 0%, 55% and 5% of the TMAs were positive for wtEGFR, HER2, HER3, HER4 and EGFRvIII respectively. Overall, we found that the expression pattern of HER family members was heterogenous, and with EGFRvIII expression being very low in both whole tumor sections and TMAs from patients with pancreatic cancer. Taken together, our results provide support for more detailed studies of co-expression of all HER family members in a larger group of pancreatic cancer patients. Such studies should help to unravel their potential as targets for therapeutic interventions as well as their prognostic significance and predictive value for response to therapy. Citation Format: Tanzeel Khan, Said A. Khelwatty, Izhar Bagwan, Alan Seddon, Angus Dalgleish, Satvinder Mudan, Helmout Modjtahedi. Expression pattern and prognostic significance of HER family members and EGFRvIII in pancreatic cancer [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 2691.

Abstract 417: Identification of next-generation EGFR degraders to treat non-small cell lung cancer (NSCLC) patients

Abstract Although EGFR-targeted tyrosine kinase inhibitors (TKIs) developed over a couple of decades have made great progress in the treatment of EGFR-mutant driven NSCLC, patients are at great risk to their lives due to drug resistance caused by constantly emerging EGFR mutations. Targeted protein degraders (TPDs), also known as heterobifunctional protein degraders or PROteolysis TArgeting Chimeras (PROTACs), have drawn great attention as a new modality to overcome drug resistance by achieving selective degradation of disease-causing proteins, like an EGFR mutant protein, which are required for the survival and proliferation of various malignant tumor cells. Therefore, we have developed a series of EGFR mutant degraders using BBT-176, a 4th generation EGFR TKI developed by Bridge BioTherapeutics, and novel EGFR inhibitors as warheads which are expected not only to treat various EGFR mutated NSCLC including C797S but also to delay drug resistant-mechanisms by further mutations in the EGFR TKI target site. We synthesized a set of heterobifunctional degraders applying Cyrus BiFx Degrader (CBD) library platform containing different types of linkers and E3 ligase binders. DC50 (half-maximal degradation concentrations) values of the EGFR degraders were obtained in multiple human EGFR mutant NSCLC cell lines, where C-2051, C-2482, and C-4383 showed excellent EGFR degradation potency (DC50 = 7-25 nM, Dmax at 100 nM = 80-97%) with high selectivity against WT EGFR. Among those compounds, C-4383 was potent in cell viability assays with EGFR mutant HCC827 (Del19) and NCI-H1975 (L858R, T790M) cell lines showing a range of GI50 values from 77 to 81 nM at 72 h of compound exposure. By contrast, the compound was much less potent in A549 cells harboring wild-type EGFR (GI50 value at 72 h of treatment, 4.2 μM). We also performed proteomic analysis of C-4383 in H1975 cells resulting that EGFR was the most degraded protein with no off-target events at 100 nM (Dmax dose). A PK study of C-4383 in rats showed good exposure with moderate CL when administered intravenously (CL = 8.51 mL/min/kg, AUC = 5911 ng•h/mL). In summary, we identified heterobifunctional degraders using a 4th generation EGFR inhibitor, BBT-176, that are active in EGFR mutant NSCLC cells harboring single or C797S-containing multiple mutations. We are currently making our efforts on the improvement of physicochemical properties of EGFR mutant targeted heterobifunctional compounds. Citation Format: Dong Hyuk Ki, Joonwoo Nam, Eunjung Kim, Hunmi Choi, Chulwon Kim, Jiyeon Kim, Jimmy Jin, Sang-Uk Kang, Wooseok Han. Identification of next-generation EGFR degraders to treat non-small cell lung cancer (NSCLC) patients [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 417.

Detection and Significance of Cell-Free DNA Mutation in Pleural Effusion in Patients with Advanced NSCLC.

Objective To detect EGFR/KRAS genes in pleural effusion cell-free DNA in patients with advanced non-small-cell lung cancer (NSCLC) and to explore the clinical significance of EGFR/KRAS mutation status in pleural effusion. Methods A retrospective collection was performed on the specimens of pleural effusion and matched tissues from 50 patients with advanced NSCLC admitted to the hospital between January 2019 and January 2021. DNA mutation status of EGFR/KRAS in different specimens was detected and compared by pyrosequencing. The clinicopathological data and follow-up data of survival were collected. The relationship between DNA mutation and clinicopathological characteristics and prognosis was analyzed. Results In the 50 pleural effusion specimens, there were 22 cases (44.00%) with EGFR mutations (19/21 exon mutations), including 12 cases with EGFR19 deletion mutation and 10 cases with EGFR21 exon L858R mutation. There were 6 cases (12.00%) with KRAS mutations (single-base substitution mutations), including 4 cases with 12-codon mutation and 2 cases with 13-codon mutation. In the 50 tissue specimens, there were 24 cases (48.00%) with EGFR mutations and 4 cases (8.00%) with KRAS mutations. There was no significant difference between pleural effusion specimens and tissue specimens, with good consistency (kappa = 0.920–0.779, P > 0.05). EGFR mutation in pleural effusion was related to smoking history, types of pathological tissues, and lymph node metastasis (P < 0.05). The incidence of EGFR mutation was higher in nonsmokers, patients with lung adenocarcinoma, and patients with lymph node metastasis. The carcinoembryonic antigen (CEA) in patients with EGFR mutation was higher than that with wild-type EGFR, while the level of cytokeratin 19 fragment (Cy21-1) was lower than that with wild-type EGFR (P < 0.05). The 1-year overall survival rate in the EGFR mutation group was significantly higher than that in the EGFR wild group (68.18% vs. 42.86%) (HR = 0.419, 95% CI = 0.178–0.989, and P < 0.001). Conclusion For the detection of EGFR gene mutation, the results of the pleural effusion specimens and the tumor pathological tissue specimens were well consistent and the detection of pleural effusion could be used as an alternative method when tissue specimens cannot be obtained. EGFR gene mutations are present in majority in patients with advanced NSCLC. The incidence of EGFR mutation is higher in nonsmokers, patients with lung adenocarcinoma, those with lymph node metastasis, those with high-expression CEA, and those with low-expression Cy21-1. The prognosis is better in patients with EGFR mutation.

Exploring Degradation of Mutant and Wild-Type Epidermal Growth Factor Receptors Induced by Proteolysis-Targeting Chimeras.

Several epidermal growth factor receptor (EGFR) proteolysis-targeting chimeras (PROTACs), including MS39 and MS154 developed by us, have been reported to effectively degrade the mutant but not the wild-type (WT) EGFR. However, the mechanism underlying the selectivity in degrading the mutant over the WT EGFR has not been elucidated. Here, we report comprehensive structure-activity relationship studies that led to the discovery of two novel EGFR degraders, 31 (MS9449) and 72 (MS9427), and mechanistic studies of these EGFR degraders. Compounds 31 and 72 selectively degraded the mutant but not the WT EGFR through both ubiquitination/proteasome and autophagy/lysosome pathways. Interestingly, we found that the mutant but not the WT EGFR can effectively form EGFR-PROTAC-E3 ligase ternary complexes. Furthermore, we found that PI3K inhibition sensitized WT EGFR to PROTAC-induced degradation and combination treatment with a PI3K inhibitor enhanced antiproliferation activities of EGFR degraders in cancer cells harboring WT EGFR, providing a potential therapeutic strategy for patients with WT EGFR overexpression.

Loop-Mediated Isothermal Amplification as Point-of-Care Testing for EGFR-Mutated Lung Adenocarcinoma.

Liquid biopsy has been adapted as a diagnostic test for EGFR mutations in patients with advanced or metastatic non-small cell lung cancer (NSCLC). Loop-mediated isothermal amplification (LAMP) has been widely used for the rapid detection of pathogens through DNA amplification. This study investigated the efficacy of an EGFR-LAMP assay using plasma samples of patients with resected NSCLC tumors. The EGFR status was investigated using both LAMP and next-generation sequencing (NGS) assays in cases that met the following criteria: (1) pulmonary adenocarcinoma with EGFR mutation detected by the Therascreen EGFR PCR Kit and (2) preoperative plasma samples contained enough DNA for the LAMP and NGS experiments. Among 51 specimens from patients with EGFR-mutated tumors or metastatic lymph nodes, the LAMP assay detected 1 EGFR mutation that was also detected in the NGS assay. However, a plasma sample that demonstrated EGFR wild type in the LAMP assay showed an EGFR mutant status in NGS. The detection rates (1.9% in LAMP and 3.9% in NGS) were very low in both assays, demonstrating a similar performance in detecting EGFR mutations in NSCLC tumors; therefore, it could be a more suitable test for the advanced stage, not the early stage. Notably, the LAMP assay was more time-saving, cost-effective, and straightforward. However, further investigation is required to develop a more sensitive assay.

Who are the real high-risk patients with pathological T2N0M0 non-small-cell lung cancer that can benefit from adjuvant chemotherapy?

BackgroundThe benefit of adjuvant chemotherapy (ACT) in pathological T2N0M0 non-small-cell lung cancer (NSCLC) patients is not clear.MethodsOne thousand and fifty pathological T2N0M0 NSCLC patients were included and divided into two groups: with and without ACT. A propensity score matching analysis was carried out to minimize selection bias. The significance of ACT in high-risk patients was further analyzed. The Kaplan–Meier method and Cox proportional hazards model were used to assess the impact of ACT on the overall survival (OS), disease-free survival (DFS), and cancer-specific survival.ResultsFor the entire cohort, 31.9% (335/1050) of patients received ACT. After propensity score matching, 325 pairs of patients were matched. OS and DFS were comparable between groups in the original or matched cohort, which was confirmed by the multivariate analysis (all P > 0.05). In high-risk patients, the data suggest that ACT could improve OS and DFS only in patients with tumours >4 cm (OS: P = 0.003; DFS: P = 0.013). ACT could significantly improve the 5-year OS in patients with wild-type epidermal growth factor receptor (EGFR) (P = 0.022). ACT, however, could not improve cancer-specific survival in any subgroup, including patients with tumours >4 cm or wild-type EGFR (all P > 0.05). For patients with other high-risk factors, ACT failed to benefit patients in long-term outcomes.ConclusionsIn resected pT2N0M0 NSCLC patients, those with tumours >4 cm and wild-type EGFR are real high-risk patients and could gain survival benefit from ACT. Further prospective study is needed to confirm the definition.

Anticancer Effects of Amlodipine Alone or in Combination With Gefitinib in Non-Small Cell Lung Cancer.

Amlodipine is a Ca2+ channel blocker commonly used to cardiovascular diseases such as hypertension and angina; however, its anticancer effects in lung cancer A549 cells remain unknown. In the present study, we explored the antitumor effects and molecular mechanisms underlying the action of amlodipine in non-small cell lung cancer (NSCLC) A549 cells in vitro and in vivo. We observed that amlodipine suppressed the proliferation of A549 lung cancer cells by arresting the tumor cell cycle. Mechanistically, our results revealed that amlodipine could attenuate the phosphoinositide 3 kinase (PI3K)/Akt and Raf/MEK/extracellular signal-regulated kinase (ERK) pathways through epidermal growth factor receptor (EGFR) and modulated cell cycle-related proteins such as cyclin D1, p-Rb, p27, and p21. Subsequently, amlodipine combined with gefitinib could synergistically inhibit cell proliferation by arresting the cell cycle. Moreover, amlodipine combined with gefitinib effectively attenuated the growth of A549 lung cancer xenografts when compared with monotherapy, affording an excellent therapeutic effect. Collectively, our results indicate that amlodipine alone or combined with the novel anticancer drug gefitinib might be a potential therapeutic strategy for NSCLC patients with wild-type EGFR.

DUBLIN-3 results on quality of life (QoL) in second/third-line EGFR-wild type NSCLC patients (pts) receiving docetaxel (Doc) with or without plinabulin (Plin) using the validated EORTC QLQ C30 and QLQ LC13 questionnaires.

9091 Background: Plin, a novel immune-enhancing small molecule, enhances dendritic cell maturation and T-cell proliferation. In the ITT population, the Plin/Doc combination had superior Efficacy (mOS; p = 0.0399), Safety (Gr3/4 AE rate/pt/year; p = 0.038) and QTWiST (p = 0.026) vs standard of care (SoC) Doc alone in NSCLC pts in DUBLIN-3 (Han, ESMO 2021). Here we report DUBLIN-3 QoL results. Methods: DUBLIN-3(NCT02504489) was a randomized, single-blinded (pts only), active-controlled Ph3 study in 2nd/3rd line stage IIIB/IV, EGFR wt NSCLC pts with a measurable lesion (RECIST 1.1) in the lung, and ECOG ≤ 2, conducted in US, Australia, and China. Pts (n = 559) were randomized 1:1 to Plin/Doc or Doc/Placebo (21-day (D) cycle). Doc (75 mg/m2 on D1 and Plin 30 mg/m2 on D1 and D8 were given by IV infusion. QoL was evaluated by the validated questionnaires EORTC QLQ C30 and QLQ LC13 (which is specific for Lung Cancer), and patient-reported scores were collected at baseline and D1, D8 of each cycle (C). Results: Baseline characteristics and QLQ C30 and LC13 scores were comparable between both groups. Plin/Doc was well tolerated. Cumulative C30 sand LC13 scores were calculated for each patient. Mean (SEM) change from baseline in cumulative C30 and LC13 scores were comparable for Plin/Doc and Doc in the first 10 cycles, however separated after C10 in favor of Plin/Doc (table). LC13 items in favor of Plin/Doc vs Doc alone, were items 31 (Coughing; p &lt; 0.05), 36 (Sore Mouth; p &lt; 0.01), 37 (Dysphagia; p &lt; 0.01). Conclusions: We previously reported an OS, Safety, and QTWiST benefit with Plin/Doc vs Doc alone (ESMO 2021) in EGFR wild type 2nd/3rd line NSCLC pts from DUBLIN-3. Here, we report statistically significant QoL benefits with Plin/Doc vs Doc alone, as assessed with EORTC QLQ C30 and LC13, which may be relevant to guide treatment decisions in this generally sick patient population. Clinical trial information: NCT02504489. [Table: see text]

Subgroup analysis in patients (pts) with non-squamous (N-Sq), EGFR-wild type (wt), second/third-line NSCLC from the global phase (Ph) 3 trial DUBLIN-3 (BPI-2358-103) with the plinabulin/docetaxel (Plin/Doc) combination versus Doc alone.

9090 Background: With PD-1/PD-L1 inhibitors moving to first line in NSCLC, 2nd/3rd line NSCLC is a severe unmet medical need, dominated by docetaxel-based therapies with &gt; 40% severe neutropenia and limited survival. Plin, a novel immune-enhancing small molecule, enhances dendritic cell maturation and T-Cell proliferation. In the ITT population, the Plin/Doc combination had superior Efficacy (mOS; HR = 0.82, p = 0.0399), Safety (lower Gr3/4 AE rate/pt/year (yr); p = 0.038) and better Quality of Life (QTWiST; p = 0.026) versus (vs) standard of care (SoC) Doc alone in advanced and metastatic NSCLC pts in DUBLIN-3 (Han, ESMO 2021) who failed platinum therapy. Here we report on the N-Sq pts subgroup. Methods: DUBLIN-3(NCT02504489) was a randomized, single-blind (pts only), active controlled Ph3 study in 2nd/3rd line stage IIIB/IV, EGFR wt NSCLC pts with a measurable lesion (RECIST 1.1) in the lung, and ECOG ≤ 2, conducted in US, Australia and China. Pts (n = 559) were randomized 1:1 to Plin/Doc or Doc/Placebo (21-day (D) cycle (C)). Doc (75 mg/m2 on D1 and Plin 30 mg/m2 on D1 and D8 were given by IV infusion. A post-hoc analysis of median Overall Survival (mOS) and restricted mean survival time (RMST) from K-M curves, OS rate at 24,36 and 48 month (Mo), and grade 4 neutropenia (Gr4N) rates was performed for the N-Sq patients (n = 153 for Plin/doc and n = 178 for Doc). Results: Baseline characteristics were balanced between both groups. Primary and key secondary objectives in the ITT population were met (Han, ESMO 2021). Plin/Doc was well tolerated. Estimated Adverse Event Rate per Year [95% CI] was 1.43 [1.13,1.81] for Plin/Doc versus 2.77 [2.33,3.28] for Doc alone (p &lt; 0.001). The median OS benefit is 2.6 months (p = 0.023). The table below summarizes the results for the N-Sq subgroup. Conclusions: The addition of Plin to Doc was superior to SoC Doc alone for efficacy and safety in the clinically relevant subgroup of non-squamous EGFR-wild type, 2nd/3rd line NSCLC pts. Clinical trial information: NCT02504489. [Table: see text]

PEOPLE (NTC03447678), a phase II trial to test pembrolizumab as first-line treatment in patients with advanced NSCLC with PD-L1 &lt; 50%: A multiomics approach.

9051 Background: Chemo-immunotherapy is the standard of care for patients with advanced NSCLC and PD-L1 &lt; 50%. Efficacy has been reported in this setting with single agent pembrolizumab, but no reliable biomarkers yet exist for selecting patients likely to respond to single agent immunotherapy. The aim of this trial was to identify potential new immune biomarkers associated with PFS in NSCLC patients with PD-L1 &lt; 50% treated with first line pembrolizumab. Methods: Advanced EGFR and ALK wild type treatment-naïve NSCLC patients with PD-L1 &lt; 50% were enrolled. Gene expression profile was performed using nCounter PanCancer IO 360 Panel (Nanostring) on baseline tissue. Circulating immune profiling was performed by determination of absolute cell counts with multiparametric flow cytometry on freshly isolated whole blood samples at baseline and at first radiological evaluation. Gut bacterial taxonomic abundance was obtained by shotgun metagenomic sequencing of stool sample at baseline. Pembrolizumab was administered at 200 mg flat dose every 3 weeks until 35 cycles, disease progression or unacceptable toxicity. Omics data was analyzed with sequential univariate Cox Proportional Hazards regression predicting PFS, with Benjamini-Hochberg multiple comparisons correction. Biological features significant with univariate analysis were analyzed with multivariate Least Absolute Shrinkage and Selection Operator (LASSO). Results: From May 2018 to October 2020 65 patients were enrolled. Main characteristics were: male 67.6%, smokers 87.7%, PD-L1 positive 70.8%. Median follow up and PFS were 26.4 and 2.9 months, respectively. Gene expression profile was performed in 48 patients, microbiome in 54 patients and circulating immune profiling in 56 patients at baseline and in 46 patients at first radiologic evaluation. LASSO multivariate analysis with optimal lambda of 0.28 showed high expression levels of IRF9 and COMP genes was associated with an unfavorable PFS (HR 3.03, 1.52 – 6.02, p = 0.08 and HR 1.22, 1.08 – 1.37, corrected p = 0.06, respectively). High expression levels of CD244 (HR 0.74, 0.62- 0.67, p = 0.05), PTPRC (HR 0.55, 0.38 – 0.81, p = 0.098), KLRB1 (HR 0.76, 0.66 – 0.89, p = 0.05) in tissue samples and NK cells/CD56dimCD16+ (HR 0.56, 0.41 – 0.76, p = 0.006) in peripheral blood at baseline and non classical CD14dim CD16+ monocytes (HR 0.52, 0.36 – 0.75, p = 0.004), eosinophils (CD 15+CD16-) (HR 0.62, 0.44 – 0.89, p = 0.003) lymphocytes (HR 0.28, 0.15 – 0.5, p &lt; 0.001) in peripheral blood after first radiologic evaluation were associated to a favorable PFS. No microbiome features were selected by LASSO. Conclusions: To the best of our knowledge, this is the first prospective trial in NSCLC with PD-L1 &lt; 50% performed with a multi-omic approach able to identify immune cell subsets and expression levels of genes associated to PFS under first line treatment with pembrolizumab. Clinical trial information: NTC03447678.

PEOPLE (NTC03447678), a phase II trial of first-line, single-agent pembrolizumab in advanced NSCLC with low PD-L1: Clinical outcomes and association with circulating immune biomarkers.

9033 Background: In advanced NSCLC (aNSCLC) with PD-L1 &lt; 50% chemo-immunotherapy is the standard of care. Although the activity of single agent pembrolizumab was reported, no biomarkers have been identified able to select patients who mostly benefit. The trial aimed to identify immune biomarkers associated with PFS in aNSCLC patients with PD-L1 levels &lt; 50% treated with first-line pembrolizumab. Here we reported for the first time the clinical outcomes of the trial and circulating immune profiling (CIP) biomarkers correlated to PFS. Methods: This phase II trial was conducted at Fondazione IRCCS Istituto Nazionale dei Tumori of Milan. Eligible patients were previously untreated stage IIIB-IV NSCLC, EGFR and ALK wild type with PD-L1 &lt; 50%, PS 0-2. PD-L1 was assessed with 22-C3 antibody (Dako). Patients received pembrolizumab 200 mg every 3 weeks until 35 cycles, disease progression or unacceptable toxicity. The primary endpoint was the association of immune biomarkers with PFS. OS, ORR, DCR, DoR and safety were secondary endpoints. CIP was performed by determination of absolute cell counts for 36 innate and adaptive immunity subsets through multiparametric flow cytometry on freshly isolated whole blood samples at baseline. An orthoblique principal components-based clustering approach and multivariable Cox regression model adjusted for clinical variables were used to analyse CIP variables and their correlation with clinical endpoints. Results: From May 2018 to October 2020, of 87 screened, 65 patients were enrolled. The median age was 70.9 years, most patients were male (67.7%), smoker (87.7%), non-squamous (83.1%), PDL1 + (70.8%). 12 patients (18.5%) had PS 2. During a median follow-up of 26.4 months (mo), 51 radiological progressions, 46 deaths and 60 PFS events were observed. The median PFS was 2.9 mo (95%CI 1.8 - 5.6) and the median OS was 12.1 mo (95%CI 8.7 - 17.1). The ORR was 24.1% (2 complete and 12 partial responses), DCR was 53.4% and median DoR was 14.5 mo (95%CI 6.4 - 24.9). Drug related G3-G4 adverse events were: 2 hyponatremia, 2 lipase increased, 1 pneumonitis. Out of 7 CIP clusters identified, 2 were statistically significant at multivariable analysis on 57 patients. Higher baseline counts of 8 subsets within these two clusters were associated with better PFS (HR values range: 0.88-0.98; p values range: 0.001- 0.016). The significant subsets included lymphocytes (cells expressing CD3, or CD19 or CD56, but lacking granulocyte and monocyte markers) and main NK subsets (including CD56dim CD16+, CD56dim CD16- and HLA-DR+ NK cells). Conclusions: This trial confirmed that pembrolizumab as first-line single agent is safe and active also in a subgroup of aNSCLC patients with PD-L1 &lt; 50%. CIP biomarkers can be useful to identify patients with a favourable outcome, thus avoiding the adding toxicity of chemotherapy. Clinical trial information: NTC03447678.

Association of TP53 polymorphisms with the acquisition of EGFR T790M mutations in patients with first- or second-generation EGFR-TIK progression.

e20560 Background: Lung cancer is the leading cause of cancer death worldwide. EGFR tyrosine kinase inhibitors (TKIs) has transformed management in those patients. However, the majority of patients will become resistant to EGFR-TKIs after a period of time. The T790M acquired mutation in exon 20 of the EGFR is the predominant molecular mechanism of acquired resistance. In first-line treatment of global patients with NSCLC, osimertinib had better efficacy compared to first-generation TKIs. In the FLAURA study, the median PFS with first-line osimertinib in Asians was only 16.5 months, compared to 18.6 months in the global population. Moreover, the OS benefit in the Asian population was relatively small. At the same time, the mechanism of resistance to osimertinib is very complex and patients have limited treatment options after first-line osimertinib resistance. A variety of factors can influence the decision for first-line treatment in EGFR mutation-positive patients, including follow-up regimens, the presence of brain metastases, and tolerability, all of which should be considered in the long-term treatment plan. Knowing in advance whether patients are likely to acquire EGFR T790M mutations will help in making treatment decisions. Previous studies have shown that TP53 Arg72Pro polymorphism (rs1042522) is associated with the risk and prognosis of lung cancer. Currently, the association between EGFR mutations and TP53 polymorphisms is unclear, but previous reports have suggested that patients with EGFRmutation demonstrated a higher rate of TP53 mutation than EGFR wild type patients. Therefore, this study aim to explore the association of TP53 polymorphisms (rs1042522) with EGFR T790M acquired mutations, considering the value of T790M in lung cancer treatment. Methods: We analyzed two independent cohorts of patients with EGFR-mutant NSCLC who progressed after first-line EGFR-TKIs treatment from 2013 to 2021 (cohort 1: n=108; cohort 2: n=148). All patients were tested with plasma next-generation sequencing (NGS). Results: The acquired T790M mutation rate was 36%, 30% and 43% in all patients (n = 256), cohort 1 and cohort 2, respectively. Logistic regression analysis showed that TP53 rs1042522 polymorphism was significantly associated with an increased risk of T790M acquired mutation in cohort 1 (GG versus CC: OR (95% CI) = 3.57 (1.15-12.2), P = 0.033) and cohort 2 (GG versus CC: univariable OR (95% CI) = 3.53 (1.30-10.3), P = 0.016; multivariable OR (95% CI) = 2.94 (1.04-8.87), P= 0.047). Conclusions: We found that the TP53 rs1042522 polymorphism GG was associated with EGFR T790M acquired mutations. Knowing in advance whether patients are likely to acquire EGFR T790M mutations will help in making treatment decisions.

Phase (Ph) 1/2a study of CLN-081 in patients (pts) with NSCLC with EGFR exon 20 insertion mutations (Ins20).

9007 Background: EGFR ins20-mutant NSCLC has historically been challenging to treat. While new agents targeting EGFR ins20 have recently been approved, adverse events (AEs), particularly wild type (WT) EGFR-related AEs are common. CLN-081 is a novel EGFR tyrosine kinase inhibitor (TKI) with broad activity against EGFR mutations, including ins20, and increased selectivity for ins20 versus WT EGFR. CLN-081 has been granted FDA Breakthrough Therapy Designation for the treatment of pts with EGFR ins20 NSCLC. We present updated results of the initial multicenter Ph1/2a study of CLN-081 in pts with advanced, EGFR ins20-mutant NSCLC, including 39 pts treated in an expanded cohort at the dose of 100 mg twice daily (BID). Methods: Ph1 dose escalation utilized an accelerated titration (AT) and rolling six design. Individual cohorts were expanded in Phase 1 and 2a based on prespecified protocol criteria. Pts were required to have received prior platinum-based chemotherapy. Stable, treated brain metastasis (mets) were allowed. CLN-081 is dosed in 21-day cycles. Results: As of 13 December 2021, 73 pts [median age: 65 (36-82), median lines of prior therapy: 2 (1-9), 28 (39%) with a history of brain mets] received CLN-081 at 30 mg (8), 45 mg (1), 65 mg (14), 100 mg (39), and 150 mg (11), all BID. Treatment-related AEs in ≥ 15% of pts were rash (74%), diarrhea (27%), paronychia (25%), fatigue (19%), anemia (18%), dry skin (18%), nausea (16%). Treatment-related Gr ≥ 3 AEs in ≥ 4 % of pts included anemia (10%), increased ALT (4%), and increased AST (4%). Gr 3 rash and Gr 3 diarrhea were observed in 1 and 2 pts, respectively, at 150 mg BID, while no pts treated at ≤ 100 mg BID experienced Gr 3 rash or diarrhea. Treatment-related dose reductions and discontinuations across all dose levels occurred in 10 pts (14%) and 5 pts (7%) respectively. Among 70 response-evaluable pts across all dose levels, 25 (36%) had a confirmed partial response (PR), 34 (49%) had stable disease (SD), and 3 (4%) had progressive disease as a best response. Seven pts (10%) had a PR that remained unconfirmed; 1 (1%) pt was pending a confirmatory scan. Of 36 response-evaluable pts at 100 mg BID, 14 (39%) had a confirmed PR, 17 (47%) had SD, and 1 (3%) had PD. Three pts had a PR that remained unconfirmed (8%); 1 (3%) pt was pending a confirmatory scan. Notably, among Ph1 pts treated at 100 mg BID (N = 13) in whom longer follow-up is available, the mDOR and mPFS (estimated by Kaplan-Meier) was &gt; 15 months and 12 months, respectively. Disease control (SD ≥ 6 months or any PR) was observed in 12/13 pts (92%). Updated data with additional follow-up will be presented. Conclusions: In pts with heavily-pretreated advanced EGFR ins20 NSCLC, CLN-081 has a manageable safety profile, with anti-tumor activity across the range of doses tested. Further, CLN-081 has demonstrated a favorable clinical profile at the dose of 100 mg BID, with an encouraging objective response rate, response durability, and no Gr 3 rash or diarrhea. Clinical trial information: NCT04036682.

A phase I, open-label, dose escalation, confirmation, and expansion trial of BI 1810631 as monotherapy in patients with advanced/metastatic solid tumors with HER2 aberrations.

TPS9143 Background: HER2 mutations are present in 2–4% of NSCLC tumors; of these ̃50% are exon 20 insertion (ex20ins) mutations. There is an unmet need for effective targeted therapy against HER2 mutations in solid tumors, particularly in NSCLC. Historically, ex20ins mutations have responded poorly to TKIs. Moreover, TKIs that inhibit both mutant EGFR and HER2 are typically limited by toxicities associated with inhibition of wild-type EGFR. Despite the promise of trastuzumab deruxtecan and other agents in this setting, the development of orally available selective TKIs is important given the heterogeneity of HER2 aberrations, potential for combination regimens, and the risk of ILD with ADCs. BI 1810631 is a HER2 selective TKI that covalently binds to both wild-type and mutated HER2 receptors, including ex20ins, whilst sparing EGFR signaling; preclinical data suggest good tolerability and efficacy. This Phase Ia/Ib, open-label, non-randomized study aims to determine the safety, MTD, PK, pharmacodynamics, and preliminary efficacy of BI 1810631 in pts with HER2+ solid tumors (NCT04886804). Methods: ̃96 pts from 5–7 sites in the US, Netherlands, Japan, and China will be recruited. Phase Ia: consecutive cohorts of pts will receive BI 1810631 QD or BID at escalating doses. Starting dose level: 15 mg BID (̃36 pts); QD schedule will begin after one dose level above estimated therapeutic dose of BI 1810631 is determined safe by the Dose Escalation Committee (expected starting dose: 60 mg [̃30 pts]). BI 1810631 dose escalation will continue until MTD/RP2D for each schedule is determined, as well as a preferred Phase Ib schedule. Phase Ib: an initial 30 pts with HER2 ex20ins mutation-positive, pre-treated NSCLC will be enrolled, with possible inclusion of additional cohorts in the future. Overall pt inclusion criteria (Phase Ia): ≥18 years of age; histologically/cytologically confirmed HER2+ (defined as overexpression, gene amplification, non-synonymous somatic mutation, or gene rearrangement involving HER2 or NRG1) advanced/unresectable/metastatic solid tumor refractory/not suitable for standard therapy; exhausted treatment options; measurable/evaluable lesions (per RECIST v1.1); ECOG PS ≤1. Phase Ib criteria: HER2 ex20ins mutation-positive NSCLC; received ≥1 line of platinum-based combination chemotherapy in the advanced/metastatic setting. Primary endpoints: MTD based on number of DLTs/number of pts with DLTs (Phase Ia); objective response (Phase Ib). Secondary endpoints: number of pts with DLTs throughout entire treatment period and PK parameters (Phase Ia/Ib); duration of response, disease control, duration of disease control, and PFS (Phase Ib). The trial is actively recruiting with 6 pts enrolled to date. More patients may be recruited depending on whether 2 dose levels have been completed and the MTD/RP2D determined. Clinical trial information: NCT04886804.

The Therapeutic Potential of ADAMTS8 in Lung Adenocarcinoma without Targetable Therapy.

Lung cancer is well known for its high mortality worldwide. The treatment for advanced lung cancer needs more attention to improve its survival time. A disintegrin and metallopeptidase with thrombospondin motifs 8 (ADAMTS8) has been linked to several cancer types. However, its role in lung cancer is worthy of deep investigation to promote novel drug development. This study took advantage of RNA-seq and bioinformatics to verify the role that ADAMTS8 plays in lung cancer. The functional assays suggested that ADAMTS8 mediates invasion and metastasis when expressed at a low level, contributing to poor overall survival (OS). The expression of ADAMTS8 was under the regulation of GATA Binding Protein 1 (GATA1) and executed its pathologic role through Thrombospondin Type 1 Domain Containing 1 (THSD1) and ADAMTS Like 2 (ADAMTSL2). To define the impact of ADAMTS8 in the lung cancer treatment strategy, this study further grouped lung cancer patients in the TCGA database into mutated epidermal growth factor receptor (EGFR)/wild-type EGFR and programmed death ligand 1 (PD-L1) high/low groups. Importantly, the expression of ADAMTS8 was correlated positively with the recruitment of anticancer NKT cells and negatively with the infiltration of immunosuppressive Treg and exhausted T cells. The results indicated that lung cancer patients with higher ADAMTS8 levels among wild-type EGFR or low PD-L1 groups survive longer than those with lower levels do. This study indicates that ADAMTS8 might be a treatment option for patients with lung adenocarcinoma who lack efficient targeted or immunotherapies.