Fanconi anemia (FA) is an autosomal recessive disease characterized by progressive bone marrow failure, variable congenital abnormalities and a predisposition to malignancy, particularly acute myeloid leukemia (AML) and squamous cell carcinoma (SCC). Improved transplant outcomes are modifying the natural history of Fanconi Anemia. Improved transplant survival, no radiation exposure, and almost no GVHD increases the importance of addressing later SCC even further. The investigators hypothesize that quercetin will prevent or delay the development of SCC and associated complications, there by ameliorating or delaying the need for potentially lethal treatment with chemotherapy and/or radiation therapy for the same.

Funding Source - FDA Office of Orphan Products Development (OOPD)

Fanconi anemia (FA) is an autosomal recessive disease characterized by progressive bone marrow failure, variable congenital abnormalities and a predisposition to malignancy, particularly acute myeloid leukemia (AML) and squamous cell carcinoma (SCC). Currently, the only curative treatment option for the hematological complications of FA include hematopoietic cell transplantation (HCT). The investigators hypothesize that quercetin will prevent or delay the development of SCC and associated complications, there by ameliorating or delaying the need for potentially lethal treatment with chemotherapy and/or radiation therapy for the same.

This study is an open-label, single arm study. This study will enroll approximately 45 post-HCT patients with FA, and approximately 10 patients with FA without history of HCT. In both groups, patients with or without existing pre-malignant lesions or history of SCC will be allowed to participate, if they wish so and at the discretion of the PI. All patients will be treated with oral quercetin.

The investigators will determine the efficacy of Quercetin in reducing buccal micronuclei (a surrogate marker of DNA damage and susceptibility to squamous cell carcinoma due to genomic instability) in post-HCT patients with fanconi anemia (FA).

Inclusion Criteria:

• Diagnosis of FA
• Able to take enteral medication
• Patients ≥2 years

Exclusion Criteria:

• Renal failure requiring dialysis
• Total bilirubin >3 mg/dl and/or SGPT >200 at time of enrollment
• Patients receiving digoxin therapy, who are unable to discontinue either treatment due to medical reasons
• Patients who are pregnant or breastfeeding or are at risk of pregnancy or fathering a baby and are unable to use acceptable methods of birth control during the length of the study
• Patients who have received quercetin supplementation or other antioxidants within the last 30 days
• Patients receiving radiation therapy, chemotherapy or immunotherapy for treatment of SCC.

Participants were monitored for up to 30 days following the final dose of quercetin. The timing of the final dose varied based on duration of participation. 17 participants were on study for less than 1 year, the average number of months was 6.8. 31 participants completed 1-year study period. Two of these participants discontinued drug prior to 2-year time point, the average number of months was 17. 29 participants completed the full 2-year study period, the average number of months was 26.6.

48 patients were enrolled but 1 patient did not initiate quercetin so the total at risk is 47.