>= Grade peripheral sensory neuropathy (CTCAE, v. .) Nervous system disorder (paresthesias, peripheral motor neuropathy, or peripheral sensory neuropathy) ? Grade , per the CTCAE v.. Patients with > grade sensory peripheral neuropathy. Preexisting sensory neuropathy Grade ? Peripheral neuropathy >= grade sensory neuropathy or >= grade sensory neuropathy with pain within days of registration; prior neuropathy of this severity improved due to medical management such as gabapentin are potentially eligible Sensory/peripheral neuropathy. Pre-existing > grade peripheral sensory neuropathy Grade sensory or Grade painful peripheral neuropathy Patients must not have > grade sensory neuropathy No baseline peripheral sensory neuropathy >= grade Patients with evidence of >= grade peripheral sensory neuropathy Pre-existing grade >= peripheral sensory neuropathy No >= grade sensory peripheral neuropathy Peripheral sensory neuropathy at the thumbs bilaterally that interferes with function and/or activities of daily living Patients must not have grade or greater peripheral sensory neuropathy RANDOMIZED PHASE II (ARMS K AND L): Patients must not have grade or greater peripheral sensory neuropathy Sensory peripheral neuropathy >= grade Subject has known peripheral sensory neuropathy > Grade unless the absence of deep tendon reflexes is the sole neurological abnormality. Baseline peripheral sensory neuropathy ? grade Baseline of grade or worse peripheral sensory neuropathy Participant with sensory peripheral neuropathy of ? Grade at baseline, unable to swallow medication, or participants with prior history of seizure within the prior months. Preexisting sensory grade neuropathy Preexisting sensory grade >= neuropathy Current peripheral sensory neuropathy > grade Existence of peripheral sensory neuropathy >= grade (from any cause) Patients with grade sensory neuropathy at baseline Patient has >= grade peripheral sensory neuropathy or >= grade painful sensory neuropathy within days before enrollment; (NOTE: patient with peripheral neuropathy [PN] that was previously this severe but is currently improved due to ongoing therapy [e.g., gabapentin or amitriptyline] may be eligible) Grade >= sensory neuropathy at the time of enrollment No peripheral or sensory neuropathy > grade at study entry Preexisting sensory grade >= neuropathy ?Grade sensory neuropathy at baseline Sensory peripheral neuropathy greater than or equal to (>/=) Grade Evidence of sensory and/or peripheral neuropathy > grade Grade ? sensory neuropathy Sensory peripheral neuropathy greater than or equal to (>/=) Grade Grade ? sensory neuropathy Evidence of grade or greater sensory and/or peripheral neuropathy No evidence of peripheral or sensory neuropathy Patient does not have a clinically significant neurologic deficit or objective peripheral neuropathy (greater than or equal to grade ); peripheral (sensory or motor) neuropathy related to limb sparing procedure or amputation is allowed Patients with > grade sensory peripheral neuropathy Patients with ? grade sensory peripheral neuropathy