A prospective open-label, single-arm pilot study assessing the feasibility and tolerability of a topical multi-ingredient emulgel containing glucosamine sulphate, chondroitin sulphate, curcumin, Boswellia serrata , ginger, oil of wintergreen, and menthol in children with haemophilic arthropathy

Objectives: This pilot study primarily evaluated the feasibility of study procedures, intervention delivery, adherence, safety, tolerability, and acceptability of adjunctive FreeFlex ™ Emulgel in children with symptomatic hemophilic knee arthropathy. Exploratory within-subject changes in knee-specific Hemophilia Joint Health Score (HJHS), faces pain scale–revised (FPS-R), and Pediatric Haemophilia Activities List (PedHAL) were assessed to estimate treatment effects and inform the design of a future randomized controlled trial (RCT). Material and Methods: This prospective, open-label, single-arm pilot study enrolled ten male children with hemophilia A or B and symptomatic knee arthropathy. Participants applied FreeFlex ™ Emulgel twice daily for 4 weeks alongside routine care. Feasibility outcomes included intervention adherence, treatment acceptability, patient and caregiver satisfaction, and safety. Exploratory clinical outcomes included knee-specific HJHS, pain intensity measured using the FPS-R, and functional ability assessed by the PedHAL. Results: All enrolled participants completed the 4-week study with no treatment-related adverse events, supporting the feasibility and tolerability of the intervention. Patient and caregiver satisfaction was reported by 60% and 70%, respectively. All predefined progression criteria for a future RCT were met, including retention, adherence, completion of study assessments, safety, and acceptability. Exploratory analyses demonstrated improvements in mean left knee HJHS (10.0 ± 2.21 to 8.8 ± 2.66; p = 0.023) and total knee HJHS (19.0 ± 3.59–17.4 ± 4.47; p = 0.048). Mean FPS-R scores decreased by 20%, and PedHAL scores showed numerical improvements, although these changes were not statistically significant. Conclusion: This pilot study demonstrated that adjunctive use of FreeFlex ™ Emulgel was feasible, safe, well tolerated, and acceptable in children with hemophilic knee arthropathy over 4 weeks. Exploratory improvements in joint health and patient-reported outcomes support the feasibility of conducting adequately powered RCTs to further evaluate clinical efficacy and establish treatment benefits.