The antitumor activity of osimertinib plus palbociclib in non-small cell lung cancer patient-derived xenograft (PDX)/2D/3D culture models harboring EGFR amplification and CDKN2A/2B homozygous deletions.

Non-small cell lung cancer (NSCLC) patients without targetable driver mutation have limited treatment options. In this study, we aimed to explore a new therapeutic strategy by using established nine patient-derived xenograft (PDX) and two-dimensional (2D) /3D culture models with specific genetic alternations. The gene mutations and copy number aberrations were detected by next-generation sequencing and confirmed using polymerase chain reaction (PCR) followed by DNA sequencing, and genomic DNA quantitative PCR. Protein expression was evaluated by immunohistochemistry. Drug sensitivities of PDX/2D/3D models were evaluated by in vivo and in vitro antitumor assays. RNA interference was performed to silence gene expression. Our study found that 44.4 % (4/9) of cases had CDKN2A homozygous deletion (homdel), while 33.3 % (3/9) had CDKN2B homdel. Additionally, 22.2 % (2/9) had amplification (amp) in wildtype CDK4, 44.4 % (4/9) in CDK6, and 44.4 % (4/9) in EGFR. Among the cases, 77.8 % (7/9) lacked CDKN2A, and 33.3 % (3/9) had high CDK4, CDK6, and EGFR had high protein expression. Moreover, 33.3 % (3/9) had KRAS mutations, and 66.7 % (6/9) had TP53 mutations. Antitumor activity of osimertinib plus palbociclib was assessed in four PDX/2D/3D models, two of which had simultaneous EGFR amp and CDKN2A/2B homdel. The data showed that NSCLC with EGFR amp and CDKN2A/2B homdel were sensitive to combined drugs. Additional oncogenic KRAS mutation reduced the drug's antitumor effect. EGFR amp is responsible for osimertinib sensitivity. Osimertinib plus palbociclib effectively treat NSCLC with wildtype EGFR and CDK6 amp and CDKN2A/2B homdel in the absence of oncogenic KRAS mutation.

Fu JF ，Hsu CL ，Hsu PC 《NEOPLASIA》

Efficacy and safety of osimertinib plus bevacizumab versus osimertinib alone for advanced non-small-cell lung cancer with EGFR mutations: A meta-analysis of randomized controlled trials.

To systematically evaluate the efficacy and safety of osimertinib plus bevacizumab in treating advanced non-small-cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutations. Up to May 26, 2024, the databases of PubMed, EMBASE, Cochrane Library, ClinicalTrials.gov, China National Knowledge Infrastructure, Chinese Biomedical Literature, China Science and Technology Journal, and Wanfang were searched, and the randomized controlled clinical trials (RCTs) of osimertinib plus bevacizumab in the treatment of advanced EGFR-mutant NSCLC were included. Two researchers independently screened the literature, assessed the quality of the included literature, and extracted the literature data. Revman5.4 software was used for meta-analysis. A total of 824 patients were included in 10 RCTs. The results of meta-analysis showed that compared with the control group (osimertinib alone), the experimental group (osimertinib plus bevacizumab) had a higher objective response rate (ORR) (relative risk [RR] = 1.23, 95% confidence interval [CI] = 1.03-1.47, P = .02), and the experimental group could significantly reduce the expression levels of carcinoembryonic antigen (mean difference [SMD] = 0.82, 95% CI = 0.30-1.35, P = .002), vascular endothelial growth factor (SMD = 0.43, 95% CI = 0.13-0.73, P = .005), neuron-specific enolase (SMD = 0.88, 95% CI = 0.60-1.17, P < .00001), cytokeratin 19 fragments (SMD = 1.33, 95% CI = 0.34-2.33, P = .009), and carbohydrate antigen 125 (SMD = 0.46, 95% CI = 0.15-0.77, P = .004) in serum. However, the experimental group did not significantly improve the disease control rate (DCR) (RR = 1.17, 95% CI = 1.00-1.36, P = .05), 1- and 2-year progression-free survival (PFS) rates (RR = 1.15, 95% CI = 1.00-1.33, P = .05; RR = 1.02, 95% CI = 0.74-1.40, P = .92), 1- and 2-year overall survival (OS) rates (RR = 1.11, 95% CI = 0.92-1.36, P = .28; RR = 0.99, 95% CI = 0.84-1.18, P = .95). Interestingly, the results of subgroup analysis showed that the experimental group significantly improved ORR, DCR, 1-year PFS, and OS rates in the Chinese population and patients under 65 years old (P < .05). In addition, when the dose of bevacizumab was 7.5 mg/kg q3w in the experimental group, ORR, DCR, 1-year PFS, and OS rates were significantly better than those in the control group (P < .05). In terms of adverse events of drugs, the incidence of proteinuria, hypertension, oral mucositis, bleeding, nausea, and vomiting in the experimental group was higher than that in the control group (P < .05). For patients with advanced EGFR-mutant NSCLC, osimertinib plus bevacizumab has some clinical benefit compared with osimertinib alone. Still, it does not provide additional long-term survival benefits and has higher toxicity. More well-designed, multicenter RCTs are needed to identify the subgroups of patients most likely to benefit from this combination regimen and to validate the optimal dose of this combination regimen.

Yao L ，Zhang C ，Li D ，Xu L ，Yang X ... -  《-》

Cardiac Events and Survival in Patients With EGFR-Mutant Non-Small Cell Lung Cancer Treated With Osimertinib.

Lin CY ，Chang WT ，Su PL ，Kuo CW ，Yang J ，Lin CC ，Lin SH ... -  《JAMA Network Open》

Osimertinib after definitive chemoradiotherapy in unresectable stage III epidermal growth factor receptor-mutated non-small-cell lung cancer: analyses of central nervous system efficacy and distant progression from the phase III LAURA study.

Distant metastases in non-small-cell lung cancer (NSCLC) are a poor prognostic factor that negatively impact quality of life. The central nervous system (CNS) is a common site of distant progression in epidermal growth factor receptor-mutated (EGFRm) NSCLC. Osimertinib is a third-generation EGFR-tyrosine kinase inhibitor recommended for advanced EGFRm NSCLC and as adjuvant treatment for resected EGFRm NSCLC. In LAURA (NCT03521154), osimertinib demonstrated statistically significant improvement in progression-free survival (PFS) versus placebo in unresectable stage III EGFRm NSCLC without progression during/following chemoradiotherapy (CRT). CNS efficacy and time to death or distant metastases (TTDM) analyses are reported here. Patients without progression during/following definitive platinum-based CRT were randomised 2 : 1 to receive osimertinib (80 mg daily) or placebo until progression [by blinded independent central review (BICR)] or discontinuation. The primary endpoint was PFS by BICR. CNS PFS by neuroradiologist BICR and TTDM by BICR were secondary endpoints. Overall, 216 patients were randomised (143 osimertinib, 73 placebo). Median CNS PFS by neuroradiologist BICR was not reached [95% confidence interval (CI) not calculable (NC)-NC] with osimertinib versus 14.9 months (95% CI 7.4 months-NC) with placebo; hazard ratio (HR) for CNS PFS: 0.17 (95% CI 0.09-0.32). CNS PFS analysis by investigator assessment was consistent with BICR assessment. The cumulative incidence of CNS progression at 12 months was 9% (95% CI 5% to 14%) with osimertinib and 36% (95% CI 24% to 47%) with placebo. There was clinically meaningful improvement in TTDM with osimertinib versus placebo; HR for TTDM: 0.21 (95% CI 0.11-0.38). The cumulative incidence of distant metastases at 12 months was 11% (95% CI 6% to 17%) with osimertinib and 37% (95% CI 26% to 48%) with placebo. Osimertinib demonstrated clinically meaningful improvements in CNS PFS and TTDM versus placebo, supporting osimertinib post-CRT as the standard of care in unresectable stage III EGFRm NSCLC.

Lu S ，Ahn MJ ，Reungwetwattana T ，Özgüroğlu M ，Kato T ，Yang JC ，Huang M ，Fujiki F ，Inoue T ，Quang LV ，Sriuranpong V ，Vicente D ，Fuentes C ，Chaudhry AA ，Poole L ，Armenteros Monterroso E ，Rukazenkov Y ，van der Gronde T ，Ramalingam SS ... -  《-》

Epidermal Growth Factor Receptor (EGFR) and SMAD4 negatively correlated in the progression of gallbladder cancer in Eastern Indian patients.

Two and half percent of the Indian population suffer from gallbladder cancer (GBC). The primary factors that lead GBC are associated with mutation of several protooncogenes such as EGFR, ERBB2, Myc, and CCND1 along with dysregulation of several tumor suppressor genes such as SMAD4 and CDKN2A. Bacterial infection caused by S.typhi and H.pylori are also hypothesized to be potential factors driving GBC. This study aims to investigate the molecular mechanisms driving the progression of gallbladder adenocarcinoma in Eastern Indian patients. We specifically focussed on analyzing the mutational status of the KRAS gene, examining the amplification of the ERBB2/Her2-neu gene, and evaluating the expression patterns of six dysregulated genes (CCND1, MYC, EGFR, ERBB2/Her2-neu, CDKN2A, SMAD4). Additionally, we assessed the expression status of TGF-beta, the association between bacterial infections (S. Typhi and H. pylori) and GBC, and the impact of single nucleotide polymorphisms in ERBB2/Her2-neu and CCND1 genes within this population. Sixty-seven samples from GBC-diagnosed patients, 26 other unrelated GBC samples for validation cohort, and 68 gallstone tissue samples were collected for this study. Genomic DNA from normal as well as tumor tissues were isolated, exon 2 and exon 3 of KRAS gene were amplified along, DNA sequenced and analyzed. KRAS codon 12 mutation was detected by allele specific PCR (ASPCR) method. Amplification of UreC A (coding for urease subunit α), VacA (coding for Vacuolating cytotoxin A) and CagA genes (coding for cytotoxin-associated gene A) in H.pylori were amplified using PCR. Similarly, FlicC (coding for flagellin gene C) in S.typhi was amplified using PCR. The ERBB2/Her2-neu SNP I655V, and CCND1 SNP A870G were analyzed using PCR followed by RFLP. Expression studies of CCND1, Myc, CDKN2A, ERBB2/Her2-neu, EGFR, and SMAD4 genes were measured in GBC tumor tissues by sybr green quantitative RT PCR. The oncogenes (EGFR and ERBB2/Her2-neu) were statistically significantly overexpressed and the tumor suppressor gene (SMAD4) downregulated in our GBC tumor patient samples. The EGFR and SMAD4 genes were negatively correlated (r = -0.01) in GBC patients and the data is statistically significant and validated through IHC technique. A significant downregulation of TGF-beta had also been observed. Lower frequency (i.e. 11.5%) of KRAS mutation in GBC tumor was observed. EGFR and SMAD4 expression were found to be negatively correlated in GBC tissue samples. ERBB2 overexpression/amplification was observed in 30% of the GBC samples. We also found a low percentage of GBC samples to show KRAS codon 12 mutation in Indian GBC patient population, as had been previously documented in pancreatic cancers.

Choudhury S ，Ghosh S ，Chakraborty P ，Pal S ，Ghosh K ，Saha S ，Midha J ，Sankar V ，Mohata A ，Chattopadhyay BK ，Ghosh S ，Das S ，Basu B ，Sikdar N ... -  《BMC GASTROENTEROLOGY》