A validated liquid chromatography tandem mass spectrometry method for quantification of erlotinib, OSI-420 and didesmethyl erlotinib and semi-quantification of erlotinib metabolites in human plasma, 2015, Journal of Pharmaceutical and Biomedical Analysis, (107), [186][187][188][189][190][191][192][193][194][195] The substances were extracted using protein precipitation, separated on a BEH XBridge C18 column (100 x 2.1 mm, 1.7 µm) by gradient elution at 0.7 mL/min of acetonitrile and 5 mM ammonium acetate. The concentration was determined using a Waters Xevo triple quadrupole mass spectrometer in a multi reaction monitoring mode. The total run time was 7 minutes. Deuterated erlotinib and OSI-597 were used as internal standard for erlotinib and its metabolites respectively.Erlotinib, OSI-420 and didesmethyl erlotinib were quantified in the concentration range 25-5,000 ng/mL, 0.5-500 ng/mL and 0.15-10 ng/mL respectively. Precision and accuracy was < 14 % except for OSI-420 at LLOQ (17 %). Extraction recovery was above 89 %, 99 % and 89 % for erlotinib, OSI-420 and didesmethyl erlotinib respectively.The human liver microsomes generated 14 metabolites, three of them not previously reported.

Chemotherapy-induced myelosuppression, including thrombocytopenia, is a recurrent problem during cancer treatments that may require dose alterations or cessations that could affect the anti-tumor effect of the treatment. To identify genetic markers associated with treatment-induced thrombocytopenia, we whole-exome sequenced 215 non-small cell lung cancer patients homogeneously treated with gemcitabine/carboplatin. The decrease in platelets (defined as nadir/baseline) was used to assess treatment-induced thrombocytopenia. Association between germline genetic variants and thrombocytopenia was analyzed at single-nucleotide variant (SNV) (based on the optimal false discovery rate, the severity of predicted consequence, and effect), gene, and pathway levels. These analyses identified 130 SNVs and 25 genes associated with thrombocytopenia (P-value<0.002). 23 SNVs were validated in an independent genome-wide association study (GWAS). The top associations include rs34491125 in JMJD1C (P-value=9.07×10-5), the validated variants rs10491684 in DOCK8 (P-value=1.95×10-4), rs6118 in SERPINA5 (P-value=5.83×10-4) and rs5877 in SERPINC1 (P-value=1.07×10-3), and the genes CAPZA2 (P-value=4.03×10-4) and SERPINC1 (P-value=1.55×10-3). The SNVs in the topscoring pathway "Factors involved in megakaryocyte development and platelet production" (P-value=3.34×10-4) were used to construct weighted genetic risk scores (wGRS) and logistic regression models that predict thrombocytopenia. The wGRS predict which patients are at high or low toxicity risk levels, for CTCAE (OR=22.35, P-value=1.55×10-8), and decrease (OR=66.82, P-value=5.92×10-9). The logistic regression models predict CTCAE grades 3-4 (receiver operator characteristics (ROC) area under the curve (AUC) = 0.79), and large decrease (ROC AUC=0.86). We identified and validated genetic variations within hematopoiesis-related pathways that provide a solid foundation for future studies using genetic markers for predicting chemotherapy-induced thrombocytopenia and personalizing treatments.

A novel, rapid and sensitive liquid chromatography tandem-mass spectrometry method for quantification of vemurafenib in human plasma, that also for the first time allows for metabolite semi-quantification, was developed and validated to support clinical trials and therapeutic drug monitoring. Vemurafenib was analysed by precipitation with methanol followed by a 1.9 min isocratic liquid chromatography tandem masspectrometry analysis using an Acquity BEH C18 column with methanol and formic acid using isotope labelled internal standards. Analytes were detected in multireaction monitoring mode on a Xevo TQ. Semi-quantification of vemurafenib metabolites was performed using the same analytical system and sample preparation with gradient elution. The vemurafenib method was successfully validated in the range 0.5-100 μg/mL according to international guidelines. The metabolite method was partially validated owing to the lack of commercially available reference materials. For the first time concentration levels at steady state for melanoma patients treated with vemurafenib is presented. The low abundance of vemurafenib metabolites suggests that they lack clinical significance. Copyright © 2016 John Wiley & Sons, Ltd.

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Objectives: Gemcitabine/carboplatin treatment is known to cause severe adverse drug reactions which can lead to the need for reduction or cessation of chemotherapy. It would be beneficial to identify patients at risk of severe hematological toxicity in advance before treatment start. This study aims to identify genetic markers for gemcitabine/carboplatin-induced leukopenia and neutropenia in non-small cell lung cancer patients. Material and methods: Whole-exome sequencing was performed on 215 patients. Association analysis was performed on single-nucleotide variants (SNVs) and genes, and the validation was based on an independent genome-wide association study (GWAS). Based on the association and validation analyses the genetic variants were then selected for and used in weighted genetic risk score (wGRS) prediction models for leukopenia and neutropenia. Results: Association analysis identified 50 and 111 SNVs, and 12 and 20 genes, for leukopenia and neutropenia, respectively. Of these SNVS 20 and 19 were partially validated for leukopenia and neutropenia, respectively. The genes SVIL (p = 2.48E-06) and EFCAB2 (p = 4.63E-06) were significantly associated with leukopenia contain the partially validated SNVs rs3740003, rs10160013, rs1547169, rs10927386 and rs10927387. The wGRS prediction models showed significantly different risk scores for high and low toxicity patients. Conclusion: We have identified and partially validated genetic biomarkers in SNVs and genes correlated to gemcitabine/carboplatin-induced leukopenia and neutropenia and created wGRS models for predicting the risk of chemotherapy-induced hematological toxicity. These results provide a strong foundation for further studies of chemotherapy-induced toxicity.