OBJECTIVE: We aimed to assess differences in baseline characteristics, efficacy, and safety of advanced therapies between male and female axial spondyloarthritis (axSpA) patients in randomized controlled trials (RCTs). METHODS: We conducted a systematic literature search for RCTs assessing the efficacy of advanced therapies in axSpA patients until March 19, 2023. We extracted the following outcomes by sex: baseline participant characteristics, Assessment in Spondylarthritis International Society criteria (ASAS40/20), and the Axial Spondyloarthritis Disease Activity Score low disease activity or inactive disease (ASDAS-LDA/ID). Random-effects models were used to calculate pooled effects for responses in males vs. females for different medication classes. RESULTS: We included 79 RCTs (n=23,748, 69.7% males). Only 9 trials (11.4%), 22 trials (28%) and 9 trials (11.4%) reported baseline characteristics, efficacy endpoints and safety endpoints by sex, respectively. At baseline, females were significantly older and had higher pain scores, while males had higher c-reactive protein levels. Overall, male patients were more likely to achieve an ASAS40 response compared to female patients for all advanced therapies (Odds Ratio (OR) 1.88, 95% confidence intervals (CI) 1.44, 2.46), and for IL-17A inhibitors (i) (OR 1.82), TNFi (OR 2.42), and numerically higher for IL-17A/Fi. Male patients were also more likely to achieve an ASDAS-LDA/ID (OR 2.19, 95% CI 1.47, 3.26) across all advanced therapies and for IL-17Ai (OR 2.08) and TNFi (OR 2.42) individually. CONCLUSIONS: Female patients with axSpA are less likely to achieve efficacy outcomes on advanced therapies compared to their male counterparts, with similar differences across medication classes. Future studies should study the biological (sex-related) and socio-cultural (gender-related) mechanisms underlying these differences.