A Proof-of-Concept Assessment of the Safety and Efficacy of Intralesional Diclofenac in the Treatment of Cutaneous Neurofibromas

The objectives of this study were to assess the safety and efficacy of intralesionally administered diclofenac in the treatment of cutaneous neurofibromas in patients with NF1. This was a proof-of-concept, prospective, safety and efficacy study of the effect of intralesionally administered diclofenac 25 mg/ml given once a week to 3 target cutaneous neurofibromas for 4 consecutive weeks. Overall, there was no significant change in neurofibroma size. During the study, some treated lesions developed signs of necrosis and fell off after a few weeks, but none of the control neurofibromas fell off. There were no significant changes in patient’s vital signs. A few adverse events occurred, mostly at the injection sites. During the study, some neurofibromas developed necrosis after the diclofenac injections and eventually detached from the patient. Overall, diclofenac was well tolerated, suggesting minimal systemic exposure, which required confirmation and further studies, including bioavailability analysis.