Part 1 complete; Part 2 will not be completed.

VT30-101 is a 2-part first-in-human trial of topically administered VT30 to subjects with cutaneous venous malformations, lymphatic malformations, or mixed venolymphatic malformations associated with PIK3CA or TEK mutations.

Part 1 is a 4-week treatment, open-label, 4-sequence, escalating repeat-application cohort study, with intra-subject and inter-cohort dose escalation.

Part 2 is a 12-week treatment, randomized, placebo-controlled, double-blind, safety and exploratory efficacy study. Part 2 will be initiated only after the successful completion of Part 1 with results that demonstrate the general safety and tolerability of topically applied VT30. Up to 12 subjects who complete Part 1 may be enrolled into Part 2 of the study.

The primary objective is to evaluate the safety and tolerability of VT30. The study will also determine the dose and regimen of VT30 to be carried into Part 2 of the protocol. Other aims include documenting plasma drug levels of VT30 and VT10 and, on an exploratory basis, examining pharmacologic target engagement and change in potential efficacy readouts.

VT30-101 is designed as a Phase 1/2, first-in-human study of topically administered VT30 to subjects with cutaneous venous malformations (VMs), lymphatic malformations (LMs), or mixed venolymphatic malformations (VLMs) associated with phosphatidylinositol 3-kinase catalytic alpha polypeptide (PIK3CA) or tyrosine receptor kinase (TEK) mutations. Capillary involvement and/or extension of the lesion into subcutaneous tissues is permitted.

The study will occur in 2 parts, and in both study parts, subjects will participate in a Screening Period (up to 6 weeks) before beginning the indicated Treatment Period.

Part 1 will be an open-label, 4-sequence, escalating repeat-application study comprised of up to 4 cohorts (3 subjects per cohort, with 3 up to 6 in Cohort 4, or the final Part 1 cohort). In each cohort, subjects will be given topical VT30 for a 4-week Treatment Period. Subjects will begin treatment with the designated dose on Day 1. After 2 weeks, the Investigator will examine the treated surface area and determine if the formulation is tolerated such that the subject may apply the next dose strength of VT30 gel for the remaining duration of the Treatment Period.

Specifically, the following gel dose strengths (concentrations) are planned for Cohorts 1 through 3 in Part 1:

• Cohort 1: initiate dosing with 0.12% (w/w) gel and progress to 0.6% (w/w) gel for the final 2 weeks of the Part 1 Treatment Period (if the lower dose is tolerated)
• Cohort 2: initiate dosing with 0.6% (w/w) gel and progress to 1.2% (w/w) gel for the final 2 weeks of the Part 1 Treatment Period (if the lower dose is tolerated)
• Cohort 3: initiate dosing with 1.2% (w/w) gel and progress to 2.3% (w/w) gel for the final 2 weeks of the Part 1 Treatment Period (if the lower dose is tolerated)

A Safety Review Committee (SRC), with sponsor, investigator and independent medical representation, will provide oversight and guidance for study conduct. After 3 subjects have been dosed for at least 21 days in any of the first three Part 1 cohorts, the SRC may request additional data, approve initiation of the subsequent cohort, or mandate that additional subjects to be enrolled at either the higher or lower dose within the cohort.

After 9 subjects in Cohorts 1 through 3 (3 subjects per cohort) have completed the 4-week Treatment Period, the SRC will determine if additional subjects should be assigned to Cohort 4 (or the final Part 1 cohort) to receive the MTD (maximum tolerated dose) or MFD (maximum feasible dose) strength of VT30. Subjects in Cohort 4 will receive the designated dose strength and regimen of VT30 for a full 4 weeks.

Following the completion of Cohort 4 in Part 1, the SRC will determine whether to authorize initiation of Part 2 and will confirm the dose level and regimen to be administered in Part 2.

Part 2 will be a randomized, placebo-controlled, double-blind study containing 36 subjects assigned in a 2:1 ratio to receive either VT30 or placebo. Up to 12 subjects who complete Part 1 may enroll in Part 2, provided they meet all Part 2-specific inclusion criteria with no applicable exclusions.

After the first 12 subjects in Part 2 have completed 4 weeks of treatment, the SRC will conduct a review of blinded safety data to confirm no revisions or changes are needed to the protocol. Subsequent reviews may also be conducted to ensure continued acceptable safety and tolerability.

After subjects complete their designated Treatment Period (in Part 1 or Part 2), they will participate in a 4-week post treatment Follow-up Period.

Inclusion Criteria:

1. Have signed the current approved informed consent form
2. Have a clinically or phenotypically defined VM, LM, or mixed VLM affecting the skin
3. Lesion genotyping confirms either PIK3CA or TEK mutations, known to be pathogenic
4. Agrees to use contraception if of childbearing potential
5. Be willing and able to comply with the protocol and be available for the entire study
6. Be at least 18 to 60 years of age
7. Lesion must be amenable to defining a contiguous study treatment area of 140 cm2

Exclusion Criteria:

1. Lesion to be treated is on the face or involves mucosa
2. Presence of ulcerations on the target-treatment lesion
3. Known systemic hypersensitivity to the VT30 drug substance, its inactive ingredients, or the vehicle
4. Uncontrolled diabetes mellitus
5. Hyperlipidemia that is poorly controlled on current treatment
6. Pregnant or nursing, planning to become pregnant, or planning to father a child during the study
7. History of malignancy except successfully treated nonmetastatic cutaneous squamous cell or basal cell carcinoma and/or localized carcinoma in situ of the cervix
8. Major surgery within 8 weeks of Screening, or a surgical, laser or other procedure involving the target lesion within 8 weeks of Screening, or planned to occur during the study
9. Any other medical or personal condition that, in the opinion of the Investigator, may potentially compromise the safety or compliance of the subject, or may preclude the subject's successful completion of the clinical study
10. Medically significant infection (eg, cellulitis or abscess, or a systemic infection) within 8 weeks of Screening
11. Ongoing therapy with another topical treatment or any medication that inhibits PI3K, Akt pathway, or the mTOR pathway, or in the opinion of the Investigator, the subject requires systemic therapy for their vascular malformation condition
12. Use of a biologic or systemic immunosuppressive agent within 3 months of Screening
13. Systemic use of corticosteroids, within 30 days of Screening
14. Treatment with a small molecule investigational product within 30 days of Screening, or with any investigational biologic products within 3 months of Screening
15. Positive for hepatitis C antibody, hepatitis B surface antigen, hepatitis B core antibody, or human immunodeficiency virus
16. Alanine transaminase or aspartate transaminase laboratory values in excess of 1.5X the upper limit of normal at Screening
17. Hemoglobin A1c is >8%
18. Any other clinically significant laboratory or testing abnormality that, in the opinion of the Investigator, might confound the study, interfere with the subject's ability to complete the study, or represent a meaningful safety risk upon study enrollment

Part 1: Open label Part 2: Double blind