Search Results (4)

Background: The epidermal growth factor receptor (EGFR) is overactive in many tumors. This phase I trial evaluated the safety and preliminary efficacy of afatinib plus capecitabine in refractory pancreatic ductal adenocarcinoma (PDA), biliary tract cancers (BTC), and other solid tumors. Patients and Methods: The phase Ia study had a 3 + 3 design with capecitabine 1000 mg/m² twice daily on days 1–14 and afatinib 20 mg, 30 mg, or 40 mg daily in 21-day cycles. In phase Ib, 15 patients, each with PDA and BTC, were treated at maximum tolerated dose (MTD). Results: A total of 41 patients were enrolled. No dose-limiting toxicities were observed, and the MTD was 40 mg afatinib plus capecitabine. Among 36 response-evaluable patients, one had a partial response (3%), and eight (22%) had stable disease. Median progression-free survival (PFS) was 1.9 months (95% CI 1.0, 2.0) for PDA and 1.9 months (95% CI 1.6, 3.4) for BTC. Median overall survival (OS) was 3.2 months (95% CI 2.0, 5.8) for PDA, and 4.6 months (95% CI 1.9, 6.1) for BTC. Median OS was 5.8 months (95% CI 2.0, 9.6) for KRAS^WT PDA, and 5.0 months (95% CI 1.6, 6.1) for KRAS^WT BTC, vs. 3.9 months (95% CI 1.9, 5.8) for KRAS^MUT PDA and 3.1 months (95% CI 1.0, 22.8) for KRAS^MUT BTC, respectively. Conclusions: Afatinib plus capecitabine is tolerable but does not have clinically meaningful efficacy in refractory PDA/BTC. Future studies should test novel anti-EGFR/HER2 therapies in KRAS^WT cancers further selected with a comprehensive molecular profile. Full article

Aggressive-variant prostate cancers (AVPCs) are a subset of metastatic castrate-resistant prostate cancers (mCRPCs) characterized by defects in ≥ two of three of TP53, RB1, and PTEN (AVPCm), a profile linked to lineage plasticity, androgen indifference, and platinum sensitivity. Men with mCRPC undergoing biopsies for progression were assessed for AVPCm using immunohistochemistry (IHC), next-generation sequencing (NGS) of solid tumor DNA (stDNA), and NGS of circulating tumor DNA (ctDNA) assays in CLIA-certified labs. Biopsy characteristics, turnaround times, inter-reader concordance, and inter-assay concordance were assessed. AVPCm was detected in 13 (27%) patients via IHC, two (6%) based on stDNA, and seven (39%) based on ctDNA. The concordance of the IHC reads between pathologists was variable. IHC had a higher detection rate of AVPCm⁺ tumors with the shortest turnaround times. stDNA had challenges with copy number loss detection, limiting its detection rate. ctDNA detected the greatest proportion of AVPCm⁺ tumors but had a low tumor content in two thirds of patients. These data show the operational characteristics of AVPCm detection using various assays, and inform trial design using AVPCm as a criterion for patient selection or stratification. Full article

Fanconi anemia (FA) develops due to a mutation in one of the FANC genes that are involved in the repair of interstrand crosslinks (ICLs). FANCG, a member of the FA core complex, is essential for ICL repair. Previous FANCG-deficient mouse models were generated with drug-based selection cassettes in mixed mice backgrounds, leading to a disparity in the interpretation of genotype-related phenotype. We created a Fancg-KO (KO) mouse model using CRISPR/Cas9 to exclude these confounders. The entire Fancg locus was targeted and maintained on the immunological well-characterized C57BL/6J background. The intercrossing of heterozygous mice resulted in sub-Mendelian numbers of homozygous mice, suggesting the loss of FANCG can be embryonically lethal. KO mice displayed infertility and hypogonadism, but no other developmental problems. Bone marrow analysis revealed a defect in various hematopoietic stem and progenitor subsets with a bias towards myelopoiesis. Cell lines derived from Fancg-KO mice were hypersensitive to the crosslinking agents cisplatin and Mitomycin C, and Fancg-KO mouse embryonic fibroblasts (MEFs) displayed increased γ-H2AX upon cisplatin treatment. The reconstitution of these MEFs with Fancg cDNA corrected for the ICL hypersensitivity. This project provides a new, genetically, and immunologically well-defined Fancg-KO mouse model for further in vivo and in vitro studies on FANCG and ICL repair. Full article

Background and Aims: Multiple laboratory methods are used to screen patients with colorectal cancer (CRC) for mismatch repair (MMR) protein deficiency to identify possible Lynch syndrome patients. The goal of this study was to compare the agreement between ready-to-use immunohistochemistry (IHC) assays for MLH-1, PMS-2, MSH-2, MSH-6, and mutated BRAF at V600E and molecular methods in CRC cases. The inclusion of the BRAF V600E mutation testing is important for the identification of patients with sporadic CRC, as the BRAF V600E mutation is very rarely observed in patients with Lynch syndrome tumors. Methods: CRC cases were analyzed by ColoSeq^TM tumor sequencing assay and VENTANA MMR IHC Panel that included anti-MLH1, anti-PMS2, anti-MSH2, anti-MSH6, and anti-BRAF V600E antibodies. Additionally, CRC cases with MLH1 IHC loss were evaluated for MLH1 promoter hypermethylation. Results: One hundred and eighteen cases were analyzed. The overall percent agreement (OPA) for each evaluated marker status compared to next-generation sequencing (NGS) exceeded 96%. Twenty-three cases were positive for the BRAF V600E mutation by IHC and NGS, and twenty cases showed loss of MLH1 protein and were positive for MLH1 hypermethylation. Samples with loss of MMR protein expression by IHC demonstrated genetic and/or epigenetic alterations that were consistent with the observed protein expression patterns. Conclusions: The results of this study indicate that ready-to-use IHC assays can correctly identify the loss of MMR proteins and the presence of mutated BRAF V600E protein, supporting the utility of the VENTANA MMR IHC Panel as an aid to stratify patients with sporadic CRC vs. potential Lynch syndrome. Full article