Comprender el concepto de inmunogenicidad

Optimising the Therapeutic Interval for Biologics in Patients with Psoriasis

In our clinical experience, more than half of patients do not present a complete response to biologic drugs, or drug loses its efficacy over time. Plasma determinations of drug and anti-drug antibodies levels are an objective tool for optimisation in these patients; however, established therapeutic ranges are not suitable, so the objective of this study was to study these patients and optimise their healthcare. We have made a retrospective, observational study, using data of plasma levels of drugs and anti-drugs antibodies of infliximab, adalimumab or Etanercept, we summarise all data and make a study of sensitivity, specificity, positive and negative predictive value on current therapeutic ranges. We have found a statistically significant association between subtherapeutic levels and therapeutic failure in psoriasis treated with infliximab and adalimumab. New ranges were found with higher sensitivity than the established ones, we propose 2-10 µg/mL therapeutic range for infliximab, 3-11 µg/mL for adalimumab, and 1-7 µg/mL for etanercept. In conclusion, levels of drug and anti-drug antibodies are a decisive tool for predicting therapeutic response. The current therapeutic ranges may have minimum values that are excessively high, owing to which lowering them significantly increases the sensitivity of the test in all cases, and negative predictive value in the case of etanercept. Further prospective studies are needed to prove the usefulness of these new ranges.

Validation of an analytical method for the quantification of human fibrinogen in pharmaceutical products by size-exclusion liquid chromatography (SEC-HPLC)

Fibrinogen plays a vital role in normal homeostasis by promoting platelet aggregation, clot formation and fibrinolysis. It is quantified in finished pharmaceutical products using different methods described in pharmacopoeia, but these are inaccurate, difficult to validate and do not allow for identification of aggregates or protein products of the same formulation. The aim of this study was to develop and validate a method for quantification of the content of fibrinogen and other proteins present in pharmaceutical formulations by comparing it with current pharmacopeial methods. Fibrinogen was quantified in two commercial products and compared to a pharmacopeial method using a validated method for size-exclusion high-pressure liquid chromatography (SEC-HPLC). The fibrinogen level was in accordance with both products' specifications. The SEC-HPLC method showed that the percentage of fibrinogen was 94.88 for one product and 50.68 for the other, and detected high molecular weight aggregates in the second product. The SEC-HPLC method that we developed is an improvement to the current pharmacopeial method, because it allows for quantification of fibrinogen and determination of product purity. This is important because greater purity can reduce potential adverse effects of pharmaceutical products in patients.

Long-term survival of subcutaneous anti-tumor necrosis factor biological drugs administered between 2008 and 2012 in a cohort of rheumatoid arthritis patients

OBJECTIVE

To compare the survival of subcutaneous anti-tumor necrosis factor (TNF) drugs used between 2008 and 2012 prescribed in accordance with clinical practice.

MATERIAL AND METHODS

Retrospective, observational study of the patients in our center diagnosed with rheumatoid arthritis (RA). We included patients who had received a subcutaneous anti-TNF agent for at least 6 months. The data were analyzed using the SPSS V17.0 statistical package.

RESULTS

Forty-nine RA patients started subcutaneous biological treatment with an anti-TNF agent (32 with etanercept and 17 with adalimumab). The mean age was 45.94 years (75.5% female). The mean disease duration prior to starting anti-TNF administration was 2.67 years. The mean age at the start of treatment was 51.84 years, and the average Disease Activity Score 28 was 4.93. The median survival of the anti-TNF treatment was 8.40 years; the survival of etanercept was the longer of the two. The main reason for discontinuation was secondary failure (90.9%).

CONCLUSIONS

In routine clinical practice, the survival of subcutaneous anti-TNF treatment was extensive and was independent of whether or not the patients received concomitant immunosuppressive therapy.

Current state of biosimilars in Mexico: The position of the Mexican College of Rheumatology, 2016

The present document is a position statement of the Mexican College of Rheumatology on the use of biosimilars in rheumatic diseases. This position considers that biosimilars should be considered as interchangeable, that automatic substitution without previous notice in stable patients during follow-up is not ethical, that the approval of a biosimilar should only be given after exhaustive review of preclinical and clinical data marked by Mexican regulations, that it should be clearly stated in the nomenclature of biologic drugs which is the innovator and which is the biosimilar, that it is not correct to choose a biosimilar as treatment based only on economic reasons or extrapolate indications based only on the approval of the innovator and in the absence of safety and efficacy data for the biosimilar.