Comparative Effectiveness of Biosimilar, Reference Product and Other Erythropoiesis-Stimulating Agents (ESAs) Still Covered by Patent in Chronic Kidney Disease and Cancer Patients: An Italian Population-Based Study

Background Since 2007 biosimilars of erythropoiesis-stimulating agents (ESAs) are available on the Italian market. Very limited post-marketing data exist on the comparative effectiveness of biosimilar and originator ESAs. Aim This population-based study was aimed to compare the effects of biosimilars, reference product and other ESAs still covered by patent on hemoglobinemia in chronic kidney disease (CKD) and cancer patients in a Local Health Unit (LHU) from Northern Italy. Methods A retrospective cohort study was conducted during the years 2009-2014 using data from Treviso LHU administrative database. Incident ESA users (no ESA dispensing within 6 months prior to treatment start, i.e. index date (ID)) with at least one hemoglobin measurement within one month prior to ID (baseline Hb value) and another measurement between 2nd and 3rd month after ID (follow-up Hb value) were identified. The strength of the consumption (as total number of defined daily dose (DDD) dispensed during the follow-up divided by days of follow-up) and the difference between follow-up and baseline Hb values [delta Hb (ΔHb)] were evaluated. Based on Hb changes, ESA users were classified as non-responders (ΔHb≤0 g/dl), responders (0Delta;Hb≤2 g/dl), and highly responders (ΔHb>2 g/ dl). A multivariate ordinal logistic regression model to identify predictors for responsiveness to treatment was performed. All analyses were stratified by indication for use and type of dispensed ESA at ID. Results Overall, 1,003 incident ESA users (reference product: 252, 25.1%; other ESAs covered by patent: 303, 30.2%; biosimilars: 448, 44.7%) with CKD or cancer were eligible for the study. No statistically significant difference in the amount of dose dispensed during the follow-up among biosimilars, reference product and other ESAs covered by patent was found in both CKD and cancer. After three months from treatment start, all ESAs increased Hb values on average by 2g/dl. No differences in ΔHb as well as in frequency of non-responders, responders and highly responders among different types of ESAs were observed in both indications of use. Overall, around 15-20% of ESA users were non-responders. Strength of treatment, but no type of dispensed ESAs was found to be predictor of responsiveness to treatment. Conclusions No difference on the effects on hemoglobinemia among users of either biosimilars or reference product or ESAs covered by patent was observed in a general population from Northern Italy, despite a comparable dispensed dose of the different ESAs during the first three months of treatment

Overview of the Safety of Anti-VEGF Drugs: Analysis of the Italian Spontaneous Reporting System

Introduction: Anti-vascular endothelial growth factor (anti-VEGF) drugs are widely used for the treatment of several cancers and retinal diseases. The systemic use of anti-VEGF drugs has been associated with an increased risk of serious adverse reactions. Whether this risk is also related to intravitreal administration of anti-VEGF drugs is unclear. Objective: The aim of this study was to provide an overview of the safety of anti-VEGF drugs in oncology and ophthalmology settings using the Italian Spontaneous Reporting System (SRS). Methods: We selected all suspected adverse drug reaction (ADR) reports attributed to anti-VEGF drugs and conducted descriptive frequency analyses stratified by indication of use. As a measure of disproportionality, we calculated the proportional reporting ratio with 95% confidence intervals at the level of standardized Medical Dictionary for Regulatory Activities (MedDRA®) queries (SMQs). Results: Of a total of 2472 anti-VEGF drug-related reports, 2173 (87.9%) and 299 (12.1%) were attributed to systemic and intravitreal use of these drugs, respectively. The frequency of serious ADRs reported was higher for intravitreal administration of anti-VEGF drugs than for systemic use in patients with cancer (58.9 vs. 34.1%) (p < 0.001) and were disproportionally associated with ischemic heart disease and thromboembolic and cerebrovascular events. Most serious ADRs related to anti-VEGF drugs in patients with cancer are known and clinically relevant (e.g., gastrointestinal and vascular disorders). Conclusions: This study documented that serious ADRs and systemic toxicity may occur not only with systemic use of anti-VEGF drugs in patients with cancer but also with intravitreal administration. Close monitoring of cardio/cerebrovascular adverse events should be considered during treatment with all anti-VEGF drugs