LEDoxy-SL: A Placebo-Controlled, Double-Blind, Randomized, 24-Month Trial of Six Weeks of Daily Doxycycline Plus...

Morbidity management of filarial lymphedema remains a challenge even during the post-lymphatic filariasis elimination era in Sri Lanka despite provision of the predominantly hygiene-based WHO Essential Package of Care. Because prior studies have suggested that 6 weeks of doxycycline may reduce progression of limb lymphedema, we conducted a randomized, placebo-controlled, superiority study to evaluate this possibility in Sri Lanka. Patients aged 14 to 65 years with lymphedema in one or both legs received either 200 mg of doxycycline daily for 6 weeks or matching placebo. The primary efficacy endpoint was improvement or lack of progression in lymphedema stage at 24 months postenrollment. Secondary endpoints included change in lymphedema stage at 12 and 24 months, frequency of acute adenolymphangitis episodes, and perceived disability measured by the WHO Disability Assessment Schedule 2.0 (WHODAS 2.0). Training and supplies for limb hygiene were provided throughout the study. Two hundred participants (100 in each arm) with lymphedema of Dreyer stages 1 to 3 were enrolled. By the end of the 2-year study, 29% of the doxycycline patients and 34% of those on placebo showed improvement (i.e., a decrease in lymphedema stage), whereas 11% and 15% of the two groups showed worsening of the lymphedema. Adenolymphangitis rates were comparable in the two groups (43 doxycycline and 38 placebo recipients), although attacks lasted slightly longer in placebo patients (6.5 days versus 5.2 days). In both groups, perceived disability improved initially, with partial rebound in the second year. Only 34 adverse events affecting 24 patients (11%) occurred during the 6-week treatment period. Although doxycycline did not significantly impact lymphedema progression in this study, the results clearly indicate that clinical and personal benefits can be obtained from intensive hygiene management alone.