Discontinuing cotrimoxazole preventive therapy in HIV-infected adults who are stable on antiretroviral treatment in Uganda (COSTOP): A randomised placebo controlled trial
Cotrimoxazole (CTX) preventive therapy (CPT) reduces opportunistic infections and malaria in HIV-infected patients. In Africa, policies on sustained CPT during antiretroviral therapy (ART) differ between countries. We assessed the safety of discontinuing CPT in stable patients on ART in Uganda.
COSTOP was a double-blind placebo-controlled trial. Patients aged ≥18 years, on CPT, and stable on ART (CD4 counts ≥250 cells/μL); were randomised to daily oral placebo (PLC group) or cotrimoxazole 960 mg/tablet (CTX group). Co-primary outcomes were: (i) time to first cotrimoxazole-preventable infection, with non- inferiority of PLC defined as the upper one-sided 95% confidence limit of the adjusted hazard ratio(aHR) ≤1.25; and (ii) time to first grade 3/4 haematological adverse event.
2180 subjects (1091 PLC; 1089 CTX) were enrolled. 932 PLC and 943 CTX completed the trial after 12 months minimum follow up. Ninety-eight participants (59 PLC; 39 CTX) experienced 120 cotrimoxazole- preventable events, mainly bacterial pneumonia (72 events, 4 deaths PLC); (48 events, 2 deaths CTX). The aHR for time to first event was 1.57 (upper one-sided 95% confidence limit 2.21) in per protocol population (similar results in ITT population). 551 participants (318 CTX; 233 PLC) experienced 1043 haematological adverse events (616 CTX; 427 PLC). Time to the first adverse event, mainly neutropenia, was shorter in the CTX group (aHR 0.70 95%CI 0.59-0.82; log-rank χ2 = 18.08; P<0.0001). 362 (276 PLC, 86 CTX) participants experienced at least one episode of confirmed clinical malaria (P<0.0001).
In ART stable patients with CD4 counts ≥250 cells/μL, continued CPT significantly reduces risk of severe bacterial infections and protects against malaria, while discontinuing CPT reduces haematological adverse events.