Triapine With Chemotherapy and Radiation Therapy in Treating Patients With IB2-IVA Cervical or Vaginal Cancer

PRIMARY OBJECTIVES: I. To determine the maximum tolerable dose (MTD) and recommended phase II dose (RP2D) of oral triapine when used in combination with cisplatin plus radiation therapy. II. To determine the oral bioavailability of triapine. III. To describe the pharmacokinetics (PK) of oral and intravenous triapine. SECONDARY OBJECTIVES: I. To determine whether the metabolic complete response (mCR) rate of oral triapine in combination with cisplatin chemoradiation using fludeoxyglucose F 18 (18F-FDG)-positron emission tomography (PET)/computed tomography (CT) at post-therapy (3-month) is at least 70%. II. To determine clinical overall response rate, progression-free survival, and overall survival. III. To determine the correlation of methemoglobin proportion (%) and triapine pharmacokinetic exposure. EXPLORATORY OBJECTIVE: I. To determine whether active human immunodeficiency virus (HIV) antiretroviral therapy impacts the antitumor activity of triapine. OUTLINE: This is a dose-escalation study of triapine. Patients undergo pelvic external beam radiation therapy (EBRT) or intensity modulated radiation therapy (IMRT) 5 days per week for 5 weeks (25 fractions) with a 3-day boost in week 6, and 1 or 2 applications of low dose rate (LDR) brachytherapy in week 6 or 5 fractions of high dose rate (HDR) brachytherapy at week 4 or 5. Patients also receive triapine intravenously (IV) over 120 minutes on day 1 and orally (PO) on days 2-5, 8-12, 15-19, 22-26, and 29-33 within 90 minutes after pelvic irradiation, and cisplatin IV over 60-120 minutes once weekly for 5 weeks (days 2, 9, 16, 23, and 30). Treatment continues in the absence of disease progression or unacceptable toxicity. Patients may receive a 6th cycle of cisplatin IV during the parametrial boost or any make-up radiation treatment in a sixth week of external beam radiotherapy. Patients undergo the collection of blood samples on study and undergo magnetic resonance imaging (MRI) and FDG-PET/CT during follow-up.