Surrogate endpoints are commonly used to estimate treatment efficacy in clinical studies of chronic lymphocytic leukemia (CLL). This patient- and trial-level analysis describes the correlation between progression-free survival (PFS) and minimal residual disease (MRD) with overall survival (OS) in first-line trials for CLL. First, patient-level correlation was confirmed using source data from 12 front-line GCLLSG-trials. Additionally, a joint-frailty copula model was fitted to validate correlation in the setting of targeted therapies.Second, a meta-analysis of first-line phase III trials in CLL from 2008-2024 was performed. Treatment effect correlation was quantified from seven GCLLSG and nine published trials, using hazard ratios for time-to-event and odds ratios for binary endpoints. The GCLLSG analysis set comprised 4237 patients. Patient-level correlation for PFS/OS was strong with Spearman's Rho >0.9. The joint-frailty copula indicated a weak correlation for C/CIT with a tau of 0.52, (95% CI: 0.49 - 0.55) while the correlation was strong for TT (tau = 0.91, 95% CI: 0.89 - 0.93).The meta-analysis set contained a total of 8065 patients including 5198 (64%) patients treated with C/CIT and 2867 (36%) treated with TT. Treatment effect correlation of the hazard ratios (HR) for PFS and OS was R = 0.75 (95% CI: 0.74 - 0.76, R2 = 0.56), while correlation of end-of-treatment MRD with PFS and OS was R = 0.88 (95%CI: -0.87 - 0.89; R2 = 0.78) and 0.71 (95%CI: 0.69 - 0.73; R2 = 0.5), respectively. Patient-level correlation was confirmed in the setting of targeted therapies while treatment-effect correlation between PFS and OS remains uncertain. MRD response status showed a high treatment-effect correlation with PFS but not OS, with the caveat of a limited number of randomized trials with available MRD data.