Abstract Paclitaxel (PTX), a microtubule-targeting anticancer agent, produces a debilitating peripheral neuropathy that is accompanied by neuropathic pain. Currently, there are only marginally effective therapeutic interventions available. Consequently, patients are forced to reduce or discontinue life-saving chemotherapy to cope with the pain. Recently, a newly identified agent, P7C3-A20, was found to be protective in several models of neurodegeneration, including Parkinson's disease and traumatic brain injury. Given that PTX triggers progressive degeneration of peripheral afferent neurons, this study was performed to evaluate the potential neuroprotective efficacy of P7C3-A20 in rodent models of PTX-induced peripheral neuropathy. P7C3-A20 (10 mg/kg) or vehicle (Cremophor EL/DMSO/5% Dextrose; 1:1:3) was administered intraperitoneally (i.p.) to Sprague-Dawley rats (250-300 g) everyday over a 28-day experimental paradigm. Following two days of treatment with P7C3-A20 or vehicle, rats also received 3 injections of PTX (11.7 mg/kg, i.p.) or vehicle (Cremophor EL/DMSO/5% Dextrose; i.p.) administered every other day. Treatment with P7C3-A20 did not alter body weights or leukocyte counts in control or PTX-treated rats. PTX treatment increased sensitivity to mechanical and cold stimulation (allodynia) of the hindpaw, evidence of peripheral neuropathy. Notably, P7C3-A20 treatment prevented the development of allodynia in response to PTX. Immunohistochemical analysis of paw biopsies indicated that P7C3-A20 prevented PTX-mediated degeneration of terminal nerve endings. Collectively, these data suggest that P7C3-A30 prevented the neurotoxic effects of PTX on peripheral sensory neurons. A xenograft tumor model of triple negative breast cancer was then used to determine whether P7C3-A20 diminished the antitumoral efficacy of PTX. MDA-MB-231 tumors were bilaterally implanted into flanks of female athymic nude mice and allowed to grow for 3 weeks prior to treatment. Using the same treatment protocol as the rats, tumor-bearing mice received daily treatment with P7C3-A20 (20 mg/kg, i.p.) or vehicle for 16 days. P7C3-A20 did not alter PTX-mediated inhibition of tumor growth. Furthermore, P7C3-A20 prevented PTX-induced mechanical allodynia in the mice. Taken together, this work indicates that P7C3-A20 prevents PTX-induced neuropathic damage without diminishing its antitumoral efficacy. P7C3-A20 may be an exciting new candidate to prevent peripheral neuropathy in patients undergoing cancer treatment with PTX. Citation Format: LoCoco PM, Risinger AL, Mooberry SL, Berg KA, Clarke WP. The neuroprotective aminopropyl carbazole, P7C3-A20, prevents paclitaxel-induced pain. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-15-07.