Clinical Trials

Inclusion Criteria: 

• The participant must be at least 6 years of age at consent.
• The participant must have a clinically confirmed superficial/ cutaneous (visible on the skin) microcystic lymphatic malformation (LM), also referred to as the treatment area.
  • Via in-person skin examination the investigator must identify that the microcystic LM is:
    • Present on the surface of the skin as evidenced by blebs and/or vesicles and/or papules and/or plaques and/or leaking, crusting or bleeding on the surface of the skin, as consistent with a microcystic LM.
    • The participant’s treatment area microcystic LM is ≥ moderate on the overall CGI-S severity scale and at least two individual signs of ≥ moderate on the clinician microcystic LM multicomponent severity scale as rated by the clinician.
    • Participants who have vascular malformations that interfere with evaluating the treatment area microcystic LM, in the opinion of the investigator, should be excluded.
• The participant’s treatment area mi microcystic LM is ≥ moderate on the overall PGI-S.
• The microcystic LM treatment area must have a defined total area of  > ~9 cm^2 , and less than < ~200 cm^2 . The treatment areas within the total area do not need to be contiguous.
• At least 4 weeks have elapsed since the participant has had any major surgery and 12 months since surgery on the treatment area.
• At least 14 days have elapsed since the participant completed therapy with a Growth Factor (GF) that supports platelet, red or white cell number or function.
• Participants must not have received any investigational drug or biologic within 4 weeks or 5 half-lives, whichever is longer, prior to starting treatment with and during treatment with PTX022.
• There has been ≥ 5 months from involved field radiation (XRT) administered to the microcystic LM that will be studied.
• The participant is willing to abstain from application of other prescription or over the counter topical medications in the treatment area during the treatment period. Moisturizers and emollients are allowed.
• The participant is willing to forego medical interventional treatment (i.e., pharmacological or interventional such as sclerotherapy) of their microcystic LM with anything other than the study drug during the Treatment Period except when the Investigator believes that delay of treatment potentially might compromise the health of the subject.
• For participants aged 6 years old to < 12 years, a caregiver completing the participant assessments is available to remain consistent throughout the study.

Exclusion Criteria:

• The participant has previously participated in a clinical trial evaluating PTX-022.
• The participant’s treatment area is mainly in any wet mucosa or within the orbital rim. External genital presentation is permitted.
• Participants who are pregnant, breastfeeding or planning to become pregnant during the study including through the follow-up period.
• Participants of childbearing potential who are unwilling or unable to comply with contraception measures.
• The participant has any condition or situation which, in the Investigator's opinion, may put the subject at significant risk, could confound the study results, or could interfere significantly with the subject's participation in the study.
• Participants deemed by the investigator as unwilling or unable to remain compliant with all tests and procedures, adherence to the study drug administration regimen and other protocolrequired activities.
• The participant has used oral or topical sirolimus or a PI3K inhibitor in the past 6 months.
• The participant is using or recently used a topical, oral, or interventional treatment that might interfere with the evaluation of the study IP.
• The participant has not had photodynamic therapy (PDT) sclerotherapy or other laser surgeries to the microcystic LM identified for the study within 3 months.
• The participant is currently taking antibiotics.
• The participant has had either COVID-19 or the COVID-19 Vaccine within the last 3 weeks.
• The participant has had a recent injury to the treatment area that in the opinion of the investigator caused an exacerbation of the symptoms.
• Participants with known hypersensitivity to sirolimus.
• Known history of HIV seropositivity or known immunodeficiency.
• Participants with complicated vascular anomalies with severe systemic symptoms that require systemic therapy.
• Concurrent severe and/or uncontrolled medical disease which could compromise compliance with safety monitoring requirements for sirolimus.
• Participants previously treated for cancer within the past 5 years unless the Investigator concludes history of cancer is not confounding to safety.

Note: Other protocol defined Inclusion/Exclusion Criteria may apply.

Eligibility last updated 8/18/23. Questions regarding updates should be directed to the study team contact.