Dose Finding Trial of MK-7075 in Children and Adults With Proteus Syndrome

* INCLUSION CRITERIA:
* Meets published clinical criteria for PS.
* Measurable disease: Patients must have at least one measurable lesion for volumetric MRI or photographic CCTN.
* Has a CLIA-validated report demonstrating presence of a mosaic AKT1 c.49G\>A mutation.
* 6 years of age or older. The age limits including children and adolescents were chosen because childhood and puberty are considered to be the greatest risk for disease progression, and MK-7075 may provide the most benefit to this young group of patients. In addition, an important objective of this study is to characterize the pharmacokinetics of MK-7075 in the pediatric population since it has been better studied in adults.
* Not using nor has used within the past 6 months any medication known to affect the AKT/PI3K pathway (e.g., everolimus), reviewed by NIHCC pharmacist.
* Performance status: Patients greater than or equal to 16 years of age must have a Karnofsky performance level of greater than or equal to 40%, and adolescents 6 - 16 years old must have a Lansky performance of greater than or equal to 40%.
* Is willing to identify and allow us to communicate with an outside medical provider if needed.
* Hepatic function: Bilirubin must be less than or equal to 1.5 x the upper limit of normal and the SGPT (ALT) must be less than or equal to 2.5 x the upper limit of normal.
* Cardiac function: Must have an ejection fraction with normal limits for age by echocardiogram.
* Must have cognitive abilities to complete patient surveys/QOL assessments as appropriate for age or have an appropriate surrogate decision-maker or guardian able to complete these measures in the case of intellectually impaired adults.
* Renal function: Age-adjusted normal serum creatinine (see Table below) OR a creatinine clearance greater than or equal to 60 mL/min/1.73 m\^2.

  * Age (Years): less than or equal to 15; Serum Creatinine (mg/dl): less than or equal to1.2
  * Age (Years): \> 15; Serum Creatinine (mg/dl): less than or equal to 1.5
* Body surface area of at least 0.5 m\^2

EXCLUSION CRITERIA:

* Pregnant or breast-feeding females are excluded due to potential risks of fetal and teratogenic adverse events of an investigational agent. Pregnancy tests must be obtained prior to enrollment on this study in all females. Males or females of reproductive potential may not participate unless they have agreed to use an effective contraceptive method. Abstinence is an acceptable method of birth control.
* Patients who anticipate the need for surgical intervention within the first three cycles (3 months), as surgical intervention during the period of DLT evaluation may affect analysis of adherence and/or make the subject unevaluable.
* An investigational agent within the past 6 months.
* Ongoing radiation therapy, chemotherapy, hormonal therapy directed at the disease, immunotherapy, or biologic therapy.
* Clinically significant unrelated systemic illness, such as serious infections, hepatic, renal or other organ dysfunction, which in the judgment of the Principal or Associate Investigator would compromise the patient s ability to tolerate the agents used in this trial or are likely to interfere with the study procedures or results.
* Type I or II diabetes mellitus or is being treated with insulin or an oral hypoglycemic agent.
* Abnormal LVEF on echocardiogram.
* Patients with known extensive intestinal involvement of the disease or evidence of malabsorption that, in the investigator s opinion could compromise drug absorption.
* Patients who in the opinion of the investigator may not be able to comply with the safety monitoring requirements of the study.
* Inability to undergo MRI/CT and/or contraindication for MRI examinations following the MRI protocol. Prosthesis or orthopedic or dental braces that would interfere with volumetric analysis of target lesion on MRI.
* Evidence of a tumor, or other cancer requiring treatment with chemotherapy or radiation therapy.
* Patients with baseline (pre-treatment) QTcF\>470ms on ECG.
* Absence of an approved legal guardian or approved surrogate decision-maker in the case of intellectually impaired adults.