Sildenafil Citrate in Treating Hand-Foot Skin Reaction in Participants with Cancer

Inclusion Criteria

• Patients with a clinical diagnosis of cancer that are within +/- 3 days of initiating treatment with sorafenib, sunitinib, or regorafenib. * Note: patients treated with a combination regimen that includes sorafenib, regorafenib, or sunitinib are eligible.
• Patients must exhibit an Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2.
• Females of child-bearing potential (FOCBP) and males must agree to use adequate contraception (e.g., hormonal contraceptives such as birth control pills, patch, intrauterine device; barrier contraception such as male/female condoms, diaphragm; male partner with vasectomy; abstinence) prior to study entry, for the duration of study participation, and for 30 days following completion of therapy. Should a female patient become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately. * Note: A FOCBP is any woman (regardless of sexual orientation, having undergone a tubal ligation, or remaining celibate by choice) who meets the following criteria: ** Has not undergone a hysterectomy or bilateral oophorectomy ** Has had menses at any time in the preceding 12 consecutive months (and therefore has not been naturally postmenopausal for > 12 months)
• FOCBP must have a negative urine or serum pregnancy test within 14 days prior to registration on study.
• Patients must have the ability to understand and the willingness to sign a written informed consent prior to registration in the study.

Exclusion Criteria

• Patients with a prior diagnosis of hand-foot skin reaction are not eligible.
• Patients who have had other chemotherapy or radiotherapy within 4 weeks prior to entering the study or those who have not recovered from adverse events due to agents administered more than 4 weeks earlier are not eligible.
• Patients who have a history of allergic reactions attributed to compounds of similar chemical or biologic composition to sildenafil or phosphodiesterase-5 (PDE5) inhibitors such as vardenafil (Levitra) and tadalafil (Cialis) are not eligible.
• Patients may not be receiving any other investigational agents. * Note: it is acceptable to be on combination therapy including either sorafenib, regorafenib, and/or sunitinib.
• Patients must not use topical steroids (e.g., hydrocortisone). Topical over-the-counter antibiotics (e.g., Neosporin) and skin protectants (e.g., Vaseline, Aquaphor) for local skin fissures on hands and feet. * Note: Patients are allowed to use topical medications on other body parts, besides the hands and feet, but must use qtips or gloves for application.
• Patients taking nitrates (e.g., nitroglycerin, isosorbide mononitrate, isosorbide dinitrate) and/or alpha blockers (e.g., tamsulosin, prazosin, afluzosin, silodosin) are not eligible.
• Patients taking Viagra must have a 1 day washout period prior to treatment. * Note: patients must agree to discontinue Viagra while on study treatment.
• Female patients who are pregnant or nursing are not eligible.
• Patients must not have any condition or situation which, in the investigator’s opinion, puts the patient at significant risk, could confound the study results, or may interfere significantly with the patient’s participation in the study.
• Patients who are unable to communicate or cooperate with the investigator due to language problems, poor mental development, or impaired cerebral function are not eligible.