Background: Biologics such as rituximab and trastuzumab have improved the outcome of treatment for many cancers. However, due to their high economic burden, ‘highly similar’ products known as biosimilars have been developed and used. Yet, there is still concern surrounding comparability of efficacy and safety between the biosimilar and its reference biologic, especially regarding patients switching from the reference to the biosimilar.
Aim: To compare the efficacy and safety of rituximab and trastuzumab biosimilars to their reference biologics in oncology patients.
Methods: A systematic review with meta-analysis was conducted in accordance with the PRISMA guidelines. Medline, EMBASE and Cochrane Central were searched from inception to 26 April 2021 to obtain all randomised control trial (RCT) data reporting on safety and efficacy outcomes of oncology patients treated with rituximab or trastuzumab biosimilars.
Results: 69 RCTs were identified, of which 27 RCTs reported on patients treated with rituximab and 42 RCTs reported on patients treated with trastuzumab. The odds of achieving overall response rate in patients treated with rituximab and trastuzumab biosimilar compared to reference over at least 24 weeks of treatment was 1.06 (95% CI 0.88 – 1.26) and 1.09 (95% CI 0.93 – 1.28), respectively. Proportion of patients experiencing any treatment emergent adverse effects were comparable between arms (Rituximab, OR 1.20 [95% CI 0.98 – 1.49]); (Trastuzumab, 1.07 [95% CI 0.87 – 1.32]).
Conclusion: Biosimilars for rituximab and trastuzumab have comparable efficacy and safety for treatment naïve patients, thus use in oncology can be supported, however evidence for switching patients is lacking.