SAT0172 Economic outcomes, treatment patterns, and adverse events and reactions for patients prescribed infliximab or ct-p13 in the turkish population

Abstract

BackgroundCT-P13, a biosimilar drug product to infliximab, was approved and marketed in July 2014 in Turkey. There is little information on the costs, treatment discontinuation and adverse events and reactions between patients who switched from infliximab to CT-P13 and patients who continued infliximab.ObjectivesThe study objective was to evaluate health care costs, treatment discontinuation, and adverse events and reactions between patients who switched from infliximab to CT-P13 and patients who continued infliximab in the Turkish population.MethodsAdult patients with ≥1 claim for infliximab or CT-P13 were identified in a Turkish healthcare administrative database representing 80% of the Turkish population during the identification period (16 July 2014–31 Aug 2015). Patients were required to continuously use infliximab for ≥6 months with no hospitalizations. Eligible patients either continued on infliximab (index date: date of first infliximab prescription), or switched from infliximab to CT-P13 (index date: switch date). Patients were excluded if they had ≥1 condition with an indication for infliximab during the baseline period. Patients who switched to CT-P13 were 1:10 matched to patients who continued infliximab based on the length of infliximab use prior to the index date. Demographics and clinical characteristics were measured 12 months pre-index date. Generalized linear models were used to compare adjusted health care costs, Cox regression was used to evaluate the adjusted risk of discontinuation, and Poisson regression was used to evaluate the adjusted risk of adverse events and reactions.ResultsThe study included 1,524 patients, of whom 1,388 were continuous infliximab users and 136 switched to CT-P13. Ankylosing spondylitis and rheumatoid arthritis were the most common conditions indicated for infliximab and CT-P13; however, patients were much less likely to be switched to CT-P13 for other conditions. After adjusting for demographics and clinical characteristics, patients who switched to CT-P13 had higher outpatient ([Turkish lira] TL 269 vs TL 181; p=0.005), inpatient (TL 64 vs TL 29; p=0.313), and pharmacy costs (TL 1,473 vs TL 1,329; p=0.371), which resulted in significantly higher total health care costs (TL 2,009 vs TL 1,640; p=0.046) compared to patients who continued infliximab. Additionally, patients who switched to CT-P13 were more likely to discontinue treatment (13.2 vs 1.52 per 1000 person-years) compared to those who continued infliximab. Of patients who discontinued CT-P13, 79% switched back to infliximab. After adjusting for baseline characteristics, patients who switched to CT-P13 were significantly more likely to discontinue treatment compared to those who continued infliximab (HR=5.53; 95% CI: 4.01–7.63). There was no difference in the adjusted incidence rate ratio (IRR) between the cohorts for adverse events (IRR=0.67; 95% CI: 0.19–2.30) and reactions (IRR=0.84; 95% CI: 0.55–1.27).ConclusionsPatients who switched to CT-P13 had significantly higher health care costs and were also more l...

Systematic review: efficacy and safety of switching patients between reference and biosimilar infliximab

“…In a large, controlled review of a Turkish healthcare administrative database, safety was compared in patients that switched from reference infliximab to CT‐P13 (n = 136) to those that continued to receive reference infliximab (n = 1388) . The adjusted incidence rate ratio (95% CI) for AEs between the groups was 0.67 (0.19, 2.30), indicating no statistically significant difference.…”

“…While the results of most of the uncontrolled, observational studies suggested that switching between reference and biosimilar infliximab products is safe and efficacious, the lack of a control arm, where patients maintain treatment with reference infliximab, makes it difficult to appropriately interpret the results. The largest controlled study found was an observational study of 1524 patients, which showed the rate of discontinuation was significantly higher in patients that switched from reference infliximab to CT‐P13 compared to those maintained on reference infliximab . However, these results should also be interpreted with caution as it was not a randomised study and the reasons for switching patients were not defined.…”

Non-medical Switching from Originator Tumor Necrosis Factor Inhibitors to Their Biosimilars: Systematic Review of Randomized Controlled Trials and Real-World Studies

“…However, 26 (35%) studies did report a switch-back from biosimilar to originator therapy among patients who had reported worsened outcomes or who had requested to switch back to the originator therapy for other reasons [ 15 , 17 , 41 – 43 , 46 , 48 , 51 , 52 , 57 , 58 , 63 , 71 , 75 , 77 , 83 , 86 , 90 – 92 , 95 , 100 , 103 , 104 , 113 , 115 ]. Furthermore, most studies did not report whether they were powered to detect differences in efficacy or safety after the switch, although several multiple cohort studies did provide some statistical comparisons, albeit with divergent results [ 14 , 44 , 45 , 51 , 73 , 88 , 95 , 99 , 100 , 115 ]. Twenty-five (34%) studies reported immunogenicity data, and three (4%) studies reported individual patient-level immunogenicity outcomes.…”

“…Discontinuation rates were similarly variable across studies regardless of the patient population (gastroenterology, 0–50%; rheumatology, 3–87%). Only 8 (11%) studies (5 in rheumatologic conditions, 2 in IBDs, and 1 in multiple indications) compared overall raw discontinuation rates between the switch group and the historical/parallel originator continuer group, with divergent results [ 14 , 15 , 51 , 71 , 88 , 95 , 100 , 115 ]. In three studies, discontinuation rates were slightly numerically lower for continuers versus switchers (8% vs. 10% [ 51 ], 14% vs. 16% [ 14 ], and 26% vs. 29% [ 100 ], respectively), whereas in one study discontinuation rates were slightly numerically higher for continuers versus switchers (14% vs. 8% [ 88 ]).…”

“…In three studies, discontinuation rates were slightly numerically lower for continuers versus switchers (8% vs. 10% [ 51 ], 14% vs. 16% [ 14 ], and 26% vs. 29% [ 100 ], respectively), whereas in one study discontinuation rates were slightly numerically higher for continuers versus switchers (14% vs. 8% [ 88 ]). In contrast, in four studies, the differences between the continuer and switcher groups were more pronounced (34% vs. 87% [ 71 ], 2 vs. 13 per 1000 patient-years [ 95 ], 5% vs. 24% [ 15 ], and 38% vs. 82% [ 115 ]). In three studies, hazard ratios showed that patients who switched from an originator to its biosimilar were significantly more likely to discontinue treatment than the historical/parallel continuer cohorts [ 14 , 51 , 95 ], whereas similar analyses in two studies showed no significant differences (Table 5 ) [ 44 , 100 ].…”