Pharmacokinetics of Trastuzumab After Subcutaneous and Intravenous Administration in Obese Patients.

Background: Subcutaneous trastuzumab (T-SC) administration does not allow the historical target concentration of 20 µg/mL for efficacy to be reached, from the start of treatment in patients with a body mass index (BMI) >30 kg/m2. Objectives: To analyze the influence of the strategy of dosification (fixed vs adjusted patient's body weight dose) on the initial minimum plasma concentration (Cmin) of trastuzumab in obese patients. Methods: This was an observational, prospective study, which included patients with HER2-positive nonmetastatic breast cancer treated with trastuzumab. The determination of the Cmin of trastuzumab was performed on day +21 of the first cycle using the ELISA technique. Patients were stratified according to the strategy of dosification and BMI. Results: A total of 50 patients were included; 16 patients received the drug intravenously and 34 in a fixed dosage subcutaneous (T-SC) regimen. The proportion of patients who achieved an adequate plasma concentration since the beginning of treatment was significantly higher when the drug was administered intravenously (93.8% vs 67.6%, P = 0.042). These differences are especially greater in T-SC patients with BMI >30 kg/m2, with only 20% of patients exceeding the pharmacokinetic target. Conclusion and Relevance: Our study suggests that trastuzumab SC fixed dose of 600 mg is not equivalent to IV administration, especially in obese patients. An adequate trastuzumab exposure in this population needs patient weight-adjusted IV dosage in the first administration. The clinical relevance of these findings remains to be elucidated, and further research, including larger controlled trials, is warranted.

Sequential RAS mutations evaluation in cell-free DNA of patients with tissue RAS wild-type metastatic colorectal cancer: the PERSEIDA (Cohort 2) study.

PURPOSE: RAS (KRAS/NRAS) mutational status on a tumor biopsy is mandatory to guide the best treatment in metastatic colorectal cancer (mCRC). Determining the RAS mutational status by tumor-tissue biopsy is essential in guiding the optimal treatment decision for mCRC. RAS mutations are negative predictive factors for the use of EGFR monoclonal antibodies. Cell-free DNA (cfDNA) analysis enables minimally invasive monitoring of tumor evolution. METHODS/PATIENTS: PERSEIDA was an observational, prospective study assessing cfDNA RAS, BRAF and EGFR mutations (using Idylla™) in first-line mCRC, RAS wild-type (baseline tumor-tissue biopsy) patients (cohort 2). Plasma samples were collected before first-line treatment, after 20 ± 2 weeks, and at disease progression. RESULTS: 117 patients were included (103 received panitumumab + chemotherapy as first-line treatment). At baseline, 7 (6.8%) patients had RAS mutations, 4 (3.9%) BRAF mutations and no EGFR mutations were detected (cfDNA, panitumumab + chemotherapy subpopulation [panitumumab + Ch]). The baseline RAS mutational status concordance between tissue and liquid biopsies was 94.0% (93.2%, panitumumab + Ch). At 20 weeks, only one patient in the study (included in the panitumumab + Ch) had an emerging cfDNA RAS mutation. No emerging BRAF or EGFR mutations were reported. At disease progression, 6 patients had emergent mutations not present at baseline (RAS conversion rate: 13.3% [6/45]; 15.0% [6/40], panitumumab + Ch). CONCLUSIONS: The concordance rate between liquid and solid biopsies at baseline was very high, as previously reported, while our results suggest a considerable emergence of RAS mutations during disease progression. Thus, the dynamics of the genomic landscape in ctDNA may provide relevant information for the management of mCRC patients.

Effect of UGT, SLCO, ABCB and ABCC polymorphisms on irinotecan toxicity. / Efecto de los polimorfismos en UGT, SLCO, ABCB y ABCC en la toxicidad del tratamiento con irinotecán.

BACKGROUND AND OBJECTIVES: Evaluate the relationship between the presence of polymorphisms in genes involved in the pharmacodynamics of irinotecan (UGT1A, SLCO1B1, ABCB1 and ABCC2) and the safety of irinotecan in the treatment of metastatic colorectal cancer (mCRC). PATIENTS AND METHODS: Prospective observational, single-centre study of 30 months duration, which included patients diagnosed with mCRC treated with FOLFIRI was carried out. Toxicity was evaluated in each treatment cycle according to the Common Terminology Criteria for Adverse Events (CTCAE) v.4.0 NCI. Genomic DNA was obtained with a peripheral blood sample from an extraction method based on alkaline lysis. Genetic characterisation was performed using the LigthCycler®480 platform and allele-specific HybProbe® fluorescent probes. Analysed polymorphisms were: UGT1A1*28, UGT1A1*60, UGT1A7*1,*2,*3,*4, UGT1A7*12, UGT1A9*22, SLCO1B1 (rs11045879), ABCC2 (rs717620) and ABCB1 (rs1045642). RESULTS: Thirty-four patients were included (73.5% were male, mean age 59.9 years [27-81]) in the study. Polymorphisms rs8175347, rs17868323, rs3832043, rs11692021 and rs7577677 were associated with a higher incidence of adverse effects. Furthermore, it was observed that those patients with wild-type in UGT family genes analysed have lower rates of toxicity associated with irinotecan treatment than those with certain mutated allele (P=.010). CONCLUSIONS: These results suggest that the presence of certain polymorphisms in the UGT1A family of genes is related to the development of toxicity during treatment with irinotecan.

SEOM clinical guidelines for the treatment of follicular non-Hodgkin's lymphoma.

Follicular lymphoma (FL) is the second most common subtype of non-Hodgkin's lymphoma (NHL) in the Western world. FL constitutes the most frequent indolent lymphoma, well characterized by its clinical presentation related to nodal involvement and its morphologic and biologic features. It is often managed as an incurable disease. However, several active therapeutic approaches from the "wait and watch" strategy to the allogeneic transplantation are available for management of patients with FL and clearly have changed the natural history of this disease, achieving a long-term disease-free survival. Therapeutic decision is mostly conditioned by patient's characteristics, stage, histological grade, tumor burden, and risk-predicting factors. This article try to summarizes the diagnosis and treatment of this heterogeneous group of patients.