Hand-Foot Skin Reaction (HFSR) is a common adverse event induced by Vascular Endothelial Growth Receptor Inhibitor (VEGFRi) treatment in cancer patients. The main purpose of this study is to evaluate the safety and efficacy of OQL011 compared to vehicle ointment in treating patients with moderate to severe VEGFRi-associated HFSR. This study will also identify an optimal dosage for Phase III study and explore the pharmacokinetics profile of OQL011 in HFSR patients.

Inclusion Criteria:

• Patient must be age ≥ 18 years.
• Patient must have a confirmed cancer diagnosis for which VEGFRi treatment is indicated, and must be currently under VEGFRi-based anti-cancer therapy with stable dosage for ≥ 1 week. This treatment may be VEGFRi monotherapy or VEGFRi-based combination therapy, so long as it does not include prohibited therapies.
• Patient must have shown signs of HFSR that meet (for Part 1) the NCI CTCAE v5.0 - PPE grade 2 or higher OR (for Part 2) IGA-HFSR criteria of grade 3 or higher.
• Patient on pain medications is allowed provided they have been on stable dosage in the past 1 week and is going to continue at the same dosage.
• Patient is able to use topical medications and complete questionnaires reliably.
• Eastern Cooperative Oncology Group (ECOG) performance score ≤ 2.
• Patient must have the ability to understand and the willingness to sign a written informed consent prior to study entry.

Exclusion Criteria:

• Patient with unresolved hand or foot skin disorders (NCI CTCAE v5.0 grade 2 or higher) due to other medications within 4 weeks prior to study entry.

• Patient who is using other topical medications in the hands or feet area and cannot stop such usage >7 days ahead of randomization.

• Patient who is using other concurrent cancer medications, such as capecitabine, pegylated liposomal doxorubicin, 5-fluorouracil, dabrafenib, vemurafenib, doxorubicin, docetaxel, cytarabine, ramucirumab and bevacizumab, which may result in hand-foot syndrome (HFS).

• Patient who is under uncontrolled intercurrent illness including, but not limited to, inadequately controlled nausea, vomiting, diarrhea or other conditions which may contribute to hypovolemia, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, recent myocardial infarction, uncontrolled hypotension or hypertension, cardiac arrhythmia, or psychiatric illness and social situations that would limit compliance with study requirements.

• Patient who has contraindication with the active compound, including severe anemia, increased intracranial pressure, known hypersensitivity.

• Patient who has other skin disorders that will affect the efficacy evaluation on hands and feet area, including but not limited to, tinea of feet and hands, hand/foot eczema, palmoplantar pustulosis, palmoplantar keratosis, acrodermatitis continua etc.

• Patient who used phosphodiesterase type 5 (PDE5) inhibitors such as sildenafil, vardenafil, and tadalafil within past 7 days.

• Patient with significantly abnormal lab test:

  • Inadequate hematologic function as indicated by:

    • Absolute neutrophil counts (ANC) ≤ 1,000 /mm^3
    • Hemoglobin (Hgb) ≤ 8.0 g/dL
    • Platelet count ≤ 75,000 /mm^3
    • PT or PTT > 1.5 x ULN (if patients on anticoagulants: PT INR > 3.5 x ULN)

  • Inadequate renal and liver function as indicated by:

    • Albumin < 2.8 g/dL
    • Total bilirubin ≥ 1.5 x ULN (or ≥ 2.5 x ULN for patients with Gilbert's syndrome)
    • Aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase ≥ 3 x ULN (or ≥ 5 x ULN for patients with liver cancer)
    • Creatinine > 2.0 x ULN.

• Pregnant or nursing women.

• Women of childbearing potential who are unwilling to comply with contraceptive requirements. Highly effective contraception which include two forms of birth control method (i.e., a hormonal method plus a barrier method) is advised for at least 2 weeks prior to study treatment and during study participation.

There is no plan to make individual participant data (IPD) available to other researchers.