Background: Hand-Foot Skin Reaction (HFSR) is frequently associated with the use of multi-targeted tyrosine kinase inhibitors of the vascular endothelial growth factor receptor (VEGFRi) such as cabozantinib, regorafenib, sunitinib, and lenvatinib. HFSR affects the skin on the palms and soles and is manifested as edema, erythema, hyperkeratosis, and bullae, leading to a decrease in quality of life and interruptions in dosing. The incidence of HFSR differs among VEGFRi, ranging from 5-60% (all grades) and 1-18% (grade 3). To date, there is no FDA approved treatment for HFSR, and marginal benefit has been shown with topical urea or steroids. Although not fully elucidated, the pathogenesis of HFSR has been associated with impaired vascular repair mechanisms, caused by inhibition of VEGF signaling pathways. We hypothesize that topical stimulation of VEGFR through OQL011 will decrease the severity of HFSR symptoms via local upregulation of the VEGF/VEGFR related signaling pathways. Methods: NCT04088318 is a phase 2, double-blind, randomized controlled trial to evaluate the safety and efficacy of OQL011 compared to vehicle control in the treatment of moderate to severe HFSR in patients on VEGFRi therapy. Eligible patients will have ≥ grade 2 palmar plantar erythrodysesthesia (PPE). The study is expected to enroll 112 patients in two parts. In the first part, 42 patients will apply 0.2% OQL011 topical ointment or vehicle control (2:1 randomization) TID for six weeks. In Part 2, 70 subjects will be randomized into two additional dose levels or vehicle control in a 2:2:1 ratio. The two dose levels selected will be based on the efficacy and safety results of Part 1. The primary efficacy endpoint is improvement of NCI CTCAE v5.0 PPE to grade ≤1 by week 3. Photographs of the affected areas will be taken at Day 0, 7, 14, 21 and 42 timepoints. Superiority test will be performed to compare treatment groups, and the exposure-response relationship will be explored. In addition, an investigator global assessment (IGA) for HFSR will be used in this trial to specifically assess skin recovery and is proposed to be a new evaluation tool. The validity of IGA criteria will be evaluated by assessing the inter-rater and intra-rater reliability. The correlation between IGA, NCI CTCAE v5.0 for PPE, and patient reported outcomes including Visual Analog Scale of Pain, Hand-foot Quality of Life questionnaire will also be evaluated. This study began enrolling patients in December 2019 and is ongoing. Clinical trial information: NCT04088318