Tocilizumab for the treatment of Rheumatoid Arthritis

PICHON-RIVIERE, A.; AUGUSTOVSKI, F.; GARCIA MARTI, S.; ALCARAZ, A.; GLUJOVSKY, D.; LOPEZ, A.; REY-ARES, L.; BARDACH, A.; CIAPPONI, A; OUBIÑA, M

Documento de Evaluación de tecnologías Sanitarias

IECS

Año: 2013 p. 1 - 30

1668-2793

Rheumatoid Arthritis (RA) is a chronic disease, very common in women, characterized by polyarticular and symmetrical inflammation with potential systemic involvement. Its prevalence in Argentina is 2 every 1,000 subjects; it is a cause of employment disability and of significant increase in mortality.To treat this condition, several conventional drugs -called disease-modifying anti-rheumatic drugs (DMARDs)- are used, methotrexate being the first choice.In case of inadequate response or intolerance to these drugs, the use of biological agents is recommended, including TNF-alpha inhibitors (anti-TNFs), or other biological agents such as tocilizumab.TechnologyTocilizumab is a humanized monoclonal antibody, interleukin-6 (IL- 6) receptor inhibitor. It was approved by the FDA, EMA and ANMAT to treat moderate to severe RA with inadequate response or intolerance to one or more conventional DMARDs or anti-TNF. It is administered intravenously at 8 mg/kg/monthly doses.PurposeTo assess the available evidence on the efficacy, safety and coverage related aspects regarding the use of tocilizumab in patients with RA.MethodsA bibliographic search was carried out on the main literature databases: DARE, NHS EED, MEDLINE, on Internet general search engines, in health technology evaluation agencies and health sponsors. Priority was given to the inclusion of systematic reviews (SR); controlled, randomized clinical trials (RCTs); health technology assessments (HTA) and economic evaluations (EE); clinical practice guidelines (CPG) and coverage policies of other health systems.ResultsOne direct and two indirect meta-analyses, one RCT, three CPGs, two HTAs and twelve coverage policies were included in the report. Their main results are described below.Tocilizumab versus DMARDsOne meta-analysis published in 2013 (which included fifteen RCTs comparing tocilizumab with any DMARD, including a total of more than 5,500 patients) demonstrated tocilizumab efficacy in patients who were DMARD-naive, failed prior to DMARD or anti-TNF therapy showed an ACR (composed index evaluating the disease activity improvement compared to baseline) 20, 50 and 70 significantly higher response in tocilizumab treated patients than in control groups at Week 24, as well as a significant difference in radiologic progression decrease favoring it. Three of the studies assessed monotherapy (tocilizumab vs. DMARD) and in the rest, tocilizumab with one DMARD (generally methotrexate) was compared versus a DMARD alone.Tocilizumab versus other biological agentsThe only RCT published compared tocilizumab monotherapy versus adalimumab (325 patients) in subjects whom methotrexate treatment continuation was inadequate. It showed a significantly high decrease in DAS 28 (composite index to assess clinical response) in the tocilizumab arm.One 2012 indirect meta-analysis (including more than 16,000 patients), analyzed the efficacy of different biological agents combined with DMARDs in patients who failed standard DMARDs, and did not find significant differences in the responses of ACR 20, 50 and 70 responses between etanercept and tocilizumab. Another indirect meta-analysis published in the same year (1,873 patients) found similar ACR 20, 50 and 70 responses between tocilizumab and other biological agents, in subjects who failed an anti-TNF.The European and Argentinean CPGs from 2013, consider the use of biological therapies adequate, including tocilizumab as an alternative, in patients who failed or were intolerant to a previous DMARD or anti-TNF therapy. The European guidelines also recommend it as an alternative in case of failed biological agents other than anti-TNF. The US GPCs (2012) recommend the indication of anti-TNF agents in patients with inadequate response to DMARDs; in case of failure to this second-line treatment changing to a biological therapy is recommended, being tocilizumab one of the choices. One UK HTA from 2012 that uses an economic evaluation, considers tocilizumab indication as an additional alternative to other biological agents in case of DMARD failure, as well as in the case of inadequate response to anti-TNF and rituxumab contraindication. One US HTA from the same year describes there is not enough evidence to support the superiority of one biological agent to the other.As regards coverage policies, eight US health sponsors cover tocilizumab only in case of failure to anti-TNF therapy failure while four also cover it in case of DMARD failure.ConclusionsThere is high quality methodological evidence on the efficacy of tocilizumab therapy in patients with moderate to severe RA, however, there is not adequate evidence on its efficacy compared to other biological agents.Only one comparative study showed that in patients who cannot receive methotrexate, tocilizumab is clinically and statistically more efficacious as monotherapy when compared with adalimumab monotherapy, however, there are no other RCTs assessing its efficacy versus other biological agents, and studies based on indirect comparisons suggest that it is similar to etanercept.Some international guidelines consider its use as another alternative in case of inadequate response to DMARDs, other guidelines only consider it in case of anti-TNF or biological agent failure.In view of this, the decision regarding coverage will depend on the relative cost of tocilizumab versus the other therapies.