A Pilot Study of Metformin in Patients With a Diagnosis of Li-Fraumeni Syndrome
A Pilot Study of Metformin in Patients With a Diagnosis of Li-Fraumeni Syndrome
Background:

 -  Li Fraumeni Syndrome (LFS) is a highly penetrant, autosomal dominant cancer
 predisposition disorder. Four main cancer types including sarcoma, adrenocortical
 carcinoma, breast cancer, and malignant brain tumors commonly characterize LFS but the
 syndrome can include other cancers.

 -  Metformin is an oral biguanide drug that is approved by the FDA for the treatment of
 type II diabetes. Metformin has been associated with reduced cancer risk in several
 epidemiologic studies and reduced cancer mortality in patients with type 2 diabetes.

 -  Metformin decreases circulating insulin and IGF1, and promotes glucose uptake in
 skeletal muscle and inhibits gluconeogenesis in the liver. Elevations in circulating
 insulin and IGF1 levels have been associated with increased cancer risk.

 -  Preclinical research in animal models shows that metformin may be more toxic in cancer
 cells that have lost p53 function.

 -  Lifetime risk of cancer in LFS patients with germline TP53 mutations is estimated to be
 up to 70% by age 60, with women having excess lifetime cancer risk (up to 100%) compared
 to men (up to 80%). There are currently no approved chemopreventive agents for patients
 with LFS.

 -  Metformin has been shown to be safe and tolerable in diabetic and non-diabetics, and may
 be an ideal candidate for chemoprevention of cancer in this population.

 Objectives:

 -  Determine the tolerability of oral daily metformin in patients with LFS caused by
 germline TP53 mutations.

 -  Determine if 8 weeks of daily metformin administration has any effect on circulating
 IGF-1, insulin, and IGFBP3

 Eligibility:

 -  Must have a germline TP53 mutation and provide documentation of testing.

 -  Must have adequate organ function.

 -  Age greater than or equal to 18 years.

 Design:

 -  This is a pilot study to assess the tolerability of daily oral metformin administration
 in patients with LFS caused by germline TP53 mutations and to study the effect of
 metformin on biomarker levels in these subjects.

 -  In the absence of intolerable toxicity, a minimum of 22 patients will take metformin by
 mouth for a total of 14 weeks and then discontinue metformin for 6 weeks. The total time
 on study will be 20 weeks.

 -  Patients will be assessed for biomarker levels (IGF-1, insulin, IGFBP3) by blood sample
 at baseline, and weeks 0 and 8.
Background:

 -  Li Fraumeni Syndrome (LFS) is a highly penetrant, autosomal dominant cancer
 predisposition disorder. Four main cancer types including sarcoma, adrenocortical
 carcinoma, breast cancer, and malignant brain tumors commonly characterize LFS but the
 syndrome can include other cancers.

 -  Metformin is an oral biguanide drug that is approved by the FDA for the treatment of
 type II diabetes. Metformin has been associated with reduced cancer risk in several
 epidemiologic studies and reduced cancer mortality in patients with type 2 diabetes.

 -  Metformin decreases circulating insulin and IGF1, and promotes glucose uptake in
 skeletal muscle and inhibits gluconeogenesis in the liver. Elevations in circulating
 insulin and IGF1 levels have been associated with increased cancer risk.

 -  Preclinical research in animal models shows that metformin may be more toxic in cancer
 cells that have lost p53 function.

 -  Lifetime risk of cancer in LFS patients with germline TP53 mutations is estimated to be
 up to 70% by age 60, with women having excess lifetime cancer risk (up to 100%) compared
 to men (up to 80%). There are currently no approved chemopreventive agents for patients
 with LFS.

 -  Metformin has been shown to be safe and tolerable in diabetic and non-diabetics, and may
 be an ideal candidate for chemoprevention of cancer in this population.

 Objectives:

 -  Determine the tolerability of oral daily metformin in patients with LFS caused by
 germline TP53 mutations.

 -  Determine if 8 weeks of daily metformin administration has any effect on circulating
 IGF-1, insulin, and IGFBP3

 Eligibility:

 -  Must have a germline TP53 mutation and provide documentation of testing.

 -  Must have adequate organ function.

 -  Age greater than or equal to 18 years.

 Design:

 -  This is a pilot study to assess the tolerability of daily oral metformin administration
 in patients with LFS caused by germline TP53 mutations and to study the effect of
 metformin on biomarker levels in these subjects.

 -  In the absence of intolerable toxicity, a minimum of 22 patients will take metformin by
 mouth for a total of 14 weeks and then discontinue metformin for 6 weeks. The total time
 on study will be 20 weeks.

 -  Patients will be assessed for biomarker levels (IGF-1, insulin, IGFBP3) by blood sample
 at baseline, and weeks 0, 8, 14 and 20.
-  INCLUSION CRITERIA:

 -  All TP53 germline mutation positive adult patients will be eligible for this study.
 All patients must have a documented TP53 germline mutation.

 -  Patients with history of cancer must be in remission, with surgery completed at least
 6 months prior to enrollment and chemotherapy completed at least 1 year prior to
 enrollment (except for basel cell carcinoma of the skin).

 -  Age greater than or equal to 18 years. The doses of metformin used in this study
 exceed the maximum recommended daily dose for the pediatric population.

 -  ECOG performance status 0 or 1 or Karnofsky greater than or equal to 70%

 -  Patients must have normal organ and marrow function as defined below:

 -  Leukocytes*: greater than or equal to 3,000/microL*

 -  Absolute neutrophil count: greater than or equal to 1,500/ microL

 -  Platelets: greater than or equal to 100,000/ microL

 -  Total bilirubin: Within normal institutional limits

 -  AST(SGOT) / ALT(SGPT): less than or equal to 2.5 times institutional upper limit
 of normal

 -  Creatinine: Within normal institutional limits OR

 -  Creatinine clearance: greater than or equal to 60 mL/min/1.73m(2) if serum
 creatinine > institutional normal

 -  Note: If leukopenia is idiopathic and no other significant co-morbidities
 exist patients will not be excluded on the basis of their WBC.

 -  Metformin is a category B drug and can be used to treat gestational diabetes. Levels
 of metformin excreted in breast milk appear to be low and not clinically significant.
 However, for protocol safety reasons, we will not be enrolling pregnant and/or nursing
 women in this study as metformin as has not been extensively evaluated in non-diabetic
 pregnant and nursing women. For this reason, women of child-bearing potential must
 agree to use adequate contraception (hormonal or barrier method of birth control;
 abstinence) prior to study entry and for the duration of study participation. Women
 who are nursing will be advised to discontinue breastfeeding if the mother is treated
 with metformin. Should a woman become pregnant or suspect she is pregnant while she is
 participating in this study, she should inform Drs. Annunziata or Walcott, or protocol
 physicians/study team at NCI and her primary care provider immediately.

 -  Ability of subject to understand and the willingness to sign a written informed
 consent document.

 GENERAL EXCLUSION CRITERIA:

 -  Patients who have had stem-cell transplantation.

 -  Current use of metformin or other anti-diabetic agents, or hypersensitivity or allergy
 to metformin.

 -  Patients who are receiving any other investigational agents.

 -  Patients with history of chronic alcohol use

 -  History of allergic reactions attributed to compounds of similar chemical or biologic
 composition to metformin or other agents used in study.

 -  Patients with congestive heart failure requiring pharmacological management.

 -  Uncontrolled inter-current illness including, but not limited to, ongoing or active
 infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac
 arrhythmia, or psychiatric illness/social situations that would limit compliance with
 study requirements.

 EXCLUSION CRITERIA for 13C-MBT STUDIES:

 Exclusion criteria for 13C-MBT studies in addition to general exclusion criteria
 (pertaining to effects of oral uptake of the administered substrate or mitochondrial
 function in the liver):

 -  Gastric paresis

 -  Short gut syndrome

 -  Inflammatory bowel disease*

 -  Celiac sprue

 -  Pancreatic insufficiency or disease

 -  Any malabsorption disease/syndrome

 -  Chronic PPI use or H2 blocker use that cannot be temporarily discontinued (at least 48
 hours)

 -  Any acetaminophen, aspirin, NSAID, or statin use within 2 days of testing (known to
 affect mitochondrial function)

 -  Drugs that interfere with mitochondrial function if they are unable to be discontinued
 48 hours prior to (13)MBT testing will be excluded for this test only but eligible for
 the rest of the protocol.

 -  Any oral steroid use within 2 weeks of testing

 -  Chronic alcohol use** defined as > 2 standard drinks per day (more than 2 beers, 2
 glasses of wine, or 2 shots of liquor per day)

 -  Inflammatory bowel disease will be exclusion for the (13)C-MBT only, because even
 if well controlled we do not know the effect chronic inflammation in the bowel
 and steroid use may have on the test. The test analyzes exhaled CO2 in the breath
 and this can be affected by diet (carbohydrate heavy), exercise, and certain
 pathologies like liver disease. Also pro-inflammatory mediators have been shown
 to cause hepatocellular injury that may also interfere with results of the test.

 -  The test is currently being studied as an early detection, non-invasive
 method for liver cirrhosis. Therefore, patients who have had chronic alcohol
 use consistent with a regular pattern of alcohol consumption may have
 underlying liver disease that may affect the CO2 measurement. Further,
 alcohol changes the NADH/NAD ratio intracellularly and studies have shown
 that alcohol can inhibit methionine oxidation. Previous protocols utilizing
 the (13)C-MBT have excluded patients who consume greater than 20 g/day of
 alcohol. A standard drink is equivalent to approximately 14 g/day of alcohol
 (one 12 oz beer, one 5 oz glass of wine, or one shot of liquor). This
 information was obtained from the National Institute of Health/National
 Institute of Alcohol Abuse and Alcoholism (NIAAA):

 http://pubs.niaaa.nih.gov/publications/Practitioner/pocketguide/pocket_guide2.htm). We will
 also evaluate LFTs and should clinical concern arise, check PT/PTT and albumin. Patients
 with normal liver function and no substantial history of alcohol abuse will be eligible.

 EXCLUSION CRITERIA FOR 31P-MRS STUDIES:

 Although patients will need to sign a separate informed consent to undergo the (31)P-MRS
 studies the list below includes some of the general exclusion criteria as information for
 the caring physician. Exclusion criteria for (31)P-MRS studies in addition to general
 exclusion criteria:

 -  Inability to perform exercise with dominant leg

 -  Claustrophobia and/or inability to lie flat in MRI machine

 -  Metal medical implantable device or other MRI incompatible materials

 -  Body mass index under 19 or over 45

 -  Prior stem cell transplantation