Causes for switch‐infected patients: the NEXT study

Purpose of the study NNRTIs are commonly used to initiate HAART. Despite their demonstrated efficacy, tolerability and resistance issues could lead to a treatment change. The objective of the NEXT study was to evaluate the reasons for switching an initial non‐nucleoside based regimen in the clinical setting, and the alternative regimen selected. Methods A retrospective multicentre study was undertaken between April and October 2009. Patients from 38 Spanish centres who had changed the initial EFV or NVP‐based regimen in the previous six‐month period were included. Social‐demographic and HIV‐related data was collected from medical records. Responsible physicians were interviewed about reasons for switching the non‐nucleoside and the alternative regimen of choice. Summary of results A total of 391 HIV‐1 infected patients had changed the initial EFV or NVP‐based regimen in the previous six months. Data were available for 316 (80.8%) of them. 245/316 patients received EFV as first line (77.5%). Median time to switch the NNRTI regimen was 16.9 months, shorter in case of EFV‐based regimen, 15.4 months, than NVP‐based regimen, 20.8 months. Most of changes were observed in the first month after initiation, representing 51.3% of the discontinuations, especially in case of EFV (57.1% EFV; 31% NVP). 9.2% of the patients switched due to chronic toxicity (after the first month of treatment). CNS toxicity was the most common reason for switching therapy in the acute term in 63% of the patients. Other tolerability issues that led to treatment discontinuation in the short term were lipid abnormalities due to EFV (4.1%) and liver enzyme elevations related to NVP (7%). Rash led to a similar rate discontinuation with both NNRTIs (12%). The second reason to discontinue the first‐generation NNRTI was virological/immunological failure in 40.5% of the patients (128/316). The new regimen selected was a boosted PI regimen in 52% of the cases, and was another NNRTI based regimen in 62.3%. Physicians marked safety/tolerability as the main reason for switching in 58.5% of cases (185/316).Conclusions In the clinical setting, both acute and chronic intolerance/toxicity represents the main cause of the first line treatment change based on a first generation NNRTI, mainly EFV. CNS toxicity was the most common reason for switching therapy in the acute term. Therefore, the tolerability profile of the alternative regimen played a relevant role when switching regimens.