Chemotherapy-induced peripheral neuropathy in metastatic breast cancer patients initiating intravenous paclitaxel/nab-paclitaxel.

BACKGROUND Intravenous (IV) taxanes for metastatic breast cancer (mBC) are associated with toxicities, such as chemotherapy-induced peripheral neuropathy (CIPN), which can detrimentally impact outcomes. OBJECTIVE To assess the impact of CIPN on clinical and economic outcomes in women with mBC, initiating IV paclitaxel/ nab-paclitaxel. METHODS Adult women in the MarketScan Commercial and Medicare Supplemental Database with a mBC diagnosis, initiating IV paclitaxel or IV nab-paclitaxel (index date = first administration) from November 1, 2013, to September 30, 2018, who had no prior neuropathy diagnoses, and continuous enrollment 12 months prior to and ≥ 3 months following index were selected. Propensity score-matched CIPN and non-CIPN cohorts were defined, based on postindex CIPN diagnosis. Clinical characteristics and all-cause and breast cancer (BC)-related health care utilization and costs per patient per month (PPPM) were compared between matched CIPN and non-CIPN cohorts during follow-up. RESULTS Among the 5870 women with mBC initiating IV paclitaxel/nab-paclitaxel, 42.7% developed CIPN. The matched cohorts each included 1950 women. Patients with CIPN were more likely to have a dose reduction (46.1% vs 38.2%, P < .001) or develop depression, diabetes, insomnia, liver dysfunction, or arthritis compared with the non-CIPN cohort, P < .05. Patients with CIPN were more likely to have an inpatient admission (39.2% vs 34.9%, P < .01) or emergency department visit (46.7% vs 35.6%, P < .001), as well as all-cause and BC-related costs that were $1102 and $725 PPPM higher, respectively, than women without CIPN (P < .01). CONCLUSIONS CIPN was common in women, following IV paclitaxel/nab-paclitaxel treatment and was associated with dose reductions, the development of comorbidities, and elevated health care costs. Therapies for mBC that offer increased tolerability are needed to help improve patient outcomes and control costs.