Efficacy and safety of first-line combination therapy versus monotherapy for vitreoretinal lymphoma: a systematic review and meta-analysis

Background: Vitreoretinal lymphoma (VRL) is usually treated with a combination of intraocular methotrexate (ioMTX), high-dose intravenous methotrexate (HD-MTX), or local radiotherapy (RT) as the first options. The effectiveness and safety of monotherapy like bruton’s tyrosine kinase inhibitors (BTKi) for PVRL remain uncertain. Methods: A systematic review and meta-analysis of clinical trial data and conference abstracts in VRL patients treated with first-line combination therapy or monotherapy were conducted through a search of PubMed, Embase, and Scopus databases until December 2022. A total of 24 studies comprising 517 patients were included, and survival data were extracted from 279 patients due to inconsistent units across studies. Results: The combined treatment group used ioMTX + chemotherapy (in 4 studies), RT + chemotherapy (in 2 studies), ioMTX/HD-MTX based regimen (in 2 studies), ioMTX + RT + chemotherapy (in 2 studies), ioMTX + lenalidomide/BTKi (in 2 studies) and combination of multiple therapies (in 7 studies). The monotherapy group was mainly treated with oral monotherapies such as BTKi. The combination therapy had a higher overall response rate (ORR) and complete response rate (CRR) than monotherapy (ORR: 96% vs. 72%, CRR: 92% vs. 63%). Combination therapy also resulted in a longer median progression-free survival (28.8 months vs. 13 months, p = 0.012). However, the combination therapy group had more severe side effects (grade 3/4 toxicity) than the monotherapy group (45% vs. 8%). Conclusion: The study showed combination therapy had better OR and CR rates, longer survival, and more toxicity than monotherapy. While BTK inhibitors were well-tolerated, long-term effectiveness needs confirmation from prospective studies. In addition, given the small number of studies of monotherapy for VRL, more studies are needed to validate its effects. Trial registration: CRD42023400305.