Duloxetine (DL) in treatment of oxaliplatin-induced peripheral neuropathy (PN).

Abstract

195 Background: Oxaliplatin is commonly used to treat many GI cancers, especially colorectal (CRC), pancreatic (PC), and gastric (GC); however, peripheral neuropathy (PN) is the dose-limiting toxicity. Duloxetine (DL) is a second-generation selective serotonin and norepinephrine reuptake inhibitor (SNRI) used for the treatment of depression, anxiety, PN-associated with diabetes or ongoing pain due to medical conditions such as fibromyalgia. In this retrospective study, we evaluated the role of DL in reduction of oxaliplatin-induced neuropathy. Methods: Patients with GI cancers receiving oxaliplatin-based chemotherapy regimens from Nov 2016 to Nov 2019 were included. Patients with pre-existing PN from other etiologies such as diabetes, alcoholism, autoimmune disease, infections, hereditary, etc. were excluded. Neurological evaluations were performed serially before initiating DL and every 4 weeks thereafter according to Common Terminology Criteria for Adverse Events (CTCAE) v5.0. DL was given at 30 mg by mouth (PO) once daily and if tolerated after 3 days, was escalated to 60 mg once daily. Response was calculated to include number of patients with stable PN, improved PN, or no benefit. Adverse toxicities were graded. Results: 53 patients with median age of 53 years (range: 38 – 72) received DL for oxaliplatin-induced PN during treatment of GI cancers (CRC: 40%, PC:30%, GC: 10%, others: 10%). Improvement in PN from higher to lower grades was witnessed at 2 weeks in only 4 patients. At 4 week of DL, 3/53 (6%) patients improved from G3 PN to G2, 6/53 (11%) from G3 to G1, and 28/53 (52.8%) from G2 to G1, 14/53 (26%) and 2/53 (4%) had stable G3 and G2 PN respectively. At 8 week of DL, 10/53 (19%) of patients improved from G3 to G2, 3/53 (6%) from G2 to G1, 23/53 (43%) from G1 to G0, while 11/53 (21%), 2/53 (4%) and 4/53 (8%) remained stable at G1, G2 and G3 respectively. Overall DL resulted in a response rate of 89% and stable PN in 11%. 5 patients had to stop DL due to G3 drowsiness, insomnia, dry mouth and headache. Overall, DL was well-tolerated with majority of toxicities in G1-2 grade: dizziness (15%), drowsiness (11%), sexual side effects (11%), dry mouth (11%), insomnia (8%), headache (8%). In addition to PN, DL helped in improving depression in 50% of these patients and decreased the pain score in an additional 23%. Conclusions: DL resulted in a clinically significant improvement in PN-induced by oxaliplatin with manageable toxicity profile. Additionally, DL also improved depression and pain score. DL may be considered as an option in ameliorating PN in these patients, however, caution must be taken about DL and other drugs interaction. Our study warrants a prospective randomized trial to study the effectiveness of DL in treating oxaliplatin-induced PN. Moreover, cost effectiveness of DL in concurrently improving PN, depression and pain needs to be studied as well.