Duloxetine to Prevent Oxaliplatin-Induced Peripheral Neuropathy in Patients With Stage II-III Colorectal Cancer

The primary and secondary objectives of the study: PRIMARY OBJECTIVES: I. To determine the dosage of duloxetine hydrochloride (duloxetine) (30 mg or 60 mg daily) that appears most promising in preventing oxaliplatin-induced peripheral neuropathy (OIPN). (Phase II) II. To demonstrate that the most promising dosage of duloxetine identified in the Phase II component is more effective than placebo at preventing OIPN sensory symptoms. (Phase III) III. To demonstrate that the most promising dosage of duloxetine identified in the Phase II component is more effective than placebo at preventing oxaliplatin-induced chronic neuropathic pain. (Phase III) SECONDARY OBJECTIVES: I. To characterize toxicity in each arm, including duloxetine side effects of nausea, dry mouth, dizziness, somnolence, fatigue, and insomnia using Common Terminology Criteria for Adverse Events (CTCAE) version (v) 5.0. (Phase II) II. To compare the serially measured OIPN total sensory neuropathy scores calculated from the six individual Quality of Life Questionnaire - Chemotherapy-Induced Peripheral Neuropathy 20 (QLQ-CIPN20) questions that quantify numbness, tingling, and pain in the fingers (or hands) and toes (or feet), measured on day 1 of each cycle of oxaliplatin treatment and at 1 month post-oxaliplatin treatment between the most promising dosage of duloxetine identified in the Phase II component and placebo. (Phase III) III. To compare the serially measured Brief Pain Inventory Short Form (BPI-SF) patient-reported on the average pain scores, measured on day 1 of each cycle of oxaliplatin treatment and at 1 month post-oxaliplatin treatment between the most promising dosage of duloxetine identified in the Phase II component and placebo. IV. To characterize toxicity in each arm, including duloxetine side effects of nausea, dry mouth, dizziness, somnolence, fatigue, and insomnia using the CTCAE v 5.0. (Phase III) OUTLINE: PHASE II: Patients are randomized to 1 of 3 arms. ARM I: Patients in Phase II receive duloxetine hydrochloride 30 mg (1 duloxetine capsule) orally (PO) once daily (QD) during week 1, duloxetine hydrochloride 30 mg (1 duloxetine capsule) PO QD and placebo (1 placebo capsule) PO QD during weeks 2-16, followed by duloxetine hydrochloride 30 mg (1 duloxetine capsule) PO QD during week 17 in the absence of unacceptable toxicity. ARM II: Patients in Phase II receive duloxetine hydrochloride 30 mg (1 duloxetine capsule) orally (PO) once daily (QD) during week 1, duloxetine hydrochloride 60 mg (2 duloxetine capsules) PO QD during weeks 2-16, followed by duloxetine hydrochloride 30 mg (1 duloxetine capsule) PO QD during week 17 in the absence of unacceptable toxicity. ARM III: Patients in Phase II receive placebo (1 placebo capsule) orally (PO) once daily (QD) during week 1, placebo (2 placebo capsules) PO QD weeks 2-16, followed by placebo (1 placebo capsule) PO QD during week 17 in the absence of unacceptable toxicity. PHASE III: Patients are randomized to 1 of 2 arms. ARM I: Patients in Phase III receive most promising dose of duloxetine hydrochloride from Phase II PO QD in the absence of unacceptable toxicity. ARM II: Patients in Phase III receive placebo PO QD in the absence of unacceptable toxicity. NOTE: Patients in all arms receive standard of care oxaliplatin during weeks 1-12. After completion of study, patients are followed up at 30 days and at 3, 6, 12, and 18 months after last oxaliplatin treatment.