Fawzia Ibrahim

Bio: Fawzia Ibrahim is an academic researcher from Mansoura University. The author has contributed to research in topics: Chemistry & Detection limit. The author has an hindex of 16, co-authored 121 publications receiving 6017 citations. Previous affiliations of Fawzia Ibrahim include Memorial Sloan Kettering Cancer Center.

Mutational landscape determines sensitivity to PD-1 blockade in non–small cell lung cancer

Abstract: Immune checkpoint inhibitors, which unleash a patient’s own T cells to kill tumors, are revolutionizing cancer treatment. To unravel the genomic determinants of response to this therapy, we used whole-exome sequencing of non–small cell lung cancers treated with pembrolizumab, an antibody targeting programmed cell death-1 (PD-1). In two independent cohorts, higher nonsynonymous mutation burden in tumors was associated with improved objective response, durable clinical benefit, and progression-free survival. Efficacy also correlated with the molecular smoking signature, higher neoantigen burden, and DNA repair pathway mutations; each factor was also associated with mutation burden. In one responder, neoantigen-specific CD8+ T cell responses paralleled tumor regression, suggesting that anti–PD-1 therapy enhances neoantigen-specific T cell reactivity. Our results suggest that the genomic landscape of lung cancers shapes response to anti–PD-1 therapy.

Direct determination of ampicillin and amoxicillin residues in food samples after aqueous SDS extraction by micellar liquid chromatography with UV detection

Abstract: A simple, sensitive and rapid micellar HPLC method was optimized and validated for the analysis of amoxicillin and ampicillin residues in food samples. Analytical separation was performed in less than 7 min using a RP C18 column with UV detection at 220 nm and a micellar solution of 0.05 M sodium dodecyl sulphate, 5% 1-propanol and 0.3% triethylamine in 0.02 M phosphoric acid buffered at pH 5 as the mobile phase. The flow rate was 1 mL min−1 and the effluent was monitored at 220 nm. The micellar method was successfully applied to quantitatively determine amoxicillin and ampicillin residues in spiked chicken muscles, chicken liver, bovine muscles, liver, kidney and eggs. The method was fully validated in accordance with ICH guidelines. Linearity was in the range 0.4–20 μg mL−1 for each drug and the percentage recoveries of both drugs ranged from 95.5 to 102.3% for amoxicillin and 95.6 to 101.7% for ampicillin. High extraction efficiency of amoxicillin and ampicillin was obtained without matrix interference in the extraction process and in the subsequent chromatographic determination. An aqueous solution of SDS surfactant only was used in extraction. No organic solvent was used during the pretreatment step. Hence, it is considered an interesting technique for “green” chemistry.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

Nivolumab versus Docetaxel in Advanced Nonsquamous Non–Small-Cell Lung Cancer

Abstract: BackgroundNivolumab, a fully human IgG4 programmed death 1 (PD-1) immune-checkpoint–inhibitor antibody, disrupts PD-1–mediated signaling and may restore antitumor immunity. MethodsIn this randomized, open-label, international phase 3 study, we assigned patients with nonsquamous non–small-cell lung cancer (NSCLC) that had progressed during or after platinum-based doublet chemotherapy to receive nivolumab at a dose of 3 mg per kilogram of body weight every 2 weeks or docetaxel at a dose of 75 mg per square meter of body-surface area every 3 weeks. The primary end point was overall survival. ResultsOverall survival was longer with nivolumab than with docetaxel. The median overall survival was 12.2 months (95% confidence interval [CI], 9.7 to 15.0) among 292 patients in the nivolumab group and 9.4 months (95% CI, 8.1 to 10.7) among 290 patients in the docetaxel group (hazard ratio for death, 0.73; 96% CI, 0.59 to 0.89; P=0.002). At 1 year, the overall survival rate was 51% (95% CI, 45 to 56) with nivolumab ve...

Nivolumab versus docetaxel in advanced squamous-cell non-small-cell lung cancer

Abstract: BackgroundPatients with advanced squamous-cell non–small-cell lung cancer (NSCLC) who have disease progression during or after first-line chemotherapy have limited treatment options. This randomized, open-label, international, phase 3 study evaluated the efficacy and safety of nivolumab, a fully human IgG4 programmed death 1 (PD-1) immune-checkpoint–inhibitor antibody, as compared with docetaxel in this patient population. MethodsWe randomly assigned 272 patients to receive nivolumab, at a dose of 3 mg per kilogram of body weight every 2 weeks, or docetaxel, at a dose of 75 mg per square meter of body-surface area every 3 weeks. The primary end point was overall survival. ResultsThe median overall survival was 9.2 months (95% confidence interval [CI], 7.3 to 13.3) with nivolumab versus 6.0 months (95% CI, 5.1 to 7.3) with docetaxel. The risk of death was 41% lower with nivolumab than with docetaxel (hazard ratio, 0.59; 95% CI, 0.44 to 0.79; P<0.001). At 1 year, the overall survival rate was 42% (95% CI, 3...

PD-1 Blockade in Tumors with Mismatch-Repair Deficiency

Abstract: BackgroundSomatic mutations have the potential to encode “non-self” immunogenic antigens. We hypothesized that tumors with a large number of somatic mutations due to mismatch-repair defects may be susceptible to immune checkpoint blockade. MethodsWe conducted a phase 2 study to evaluate the clinical activity of pembrolizumab, an anti–programmed death 1 immune checkpoint inhibitor, in 41 patients with progressive metastatic carcinoma with or without mismatch-repair deficiency. Pembrolizumab was administered intravenously at a dose of 10 mg per kilogram of body weight every 14 days in patients with mismatch repair–deficient colorectal cancers, patients with mismatch repair–proficient colorectal cancers, and patients with mismatch repair–deficient cancers that were not colorectal. The coprimary end points were the immune-related objective response rate and the 20-week immune-related progression-free survival rate. ResultsThe immune-related objective response rate and immune-related progression-free survival ...

PD-1 and PD-L1 Immune Checkpoint Blockade to Treat Breast Cancer

Abstract: Immune checkpoint inhibition represents a major recent breakthrough in the treatment of malignant diseases including breast cancer. Blocking the programmed death receptor-1 (PD-1) and its ligand, PD-L1, has shown impressive antitumor activity and may lead to durable long-term disease control, especially in the triple-negative subtypes of breast cancer (TNBC). Although immune checkpoint blockade is generally well tolerated, specific immune-related adverse events (irAEs) may occur. This review summarizes the clinical efficacy, perspectives, and future challenges of using PD-1/PD-L1-directed antibodies in the treatment of breast cancer.