Clinical and economic burden of intravenous paclitaxel or nab-paclitaxel for metastatic breast cancer.

BACKGROUND: Intravenous (IV) taxane therapy for metastatic breast cancer (mBC) has been associated with toxicities and demanding dosing schedules, which can limit treatment effectiveness. OBJECTIVES: To assess treatment patterns, toxicities, and costs in women with mBC initiating IV paclitaxel or IV nab-paclitaxel. METHODS: Adult women diagnosed with BC from January 1, 2014, to September 30, 2018, were identified in the MarketScan Commercial and MarketScan Medicare Supplemental databases. Women had a metastatic disease diagnosis and newly initiated treatment with IV paclitaxel/nab-paclitaxel (first administration date was considered the index date), and continuous enrollment for at least 12 months prior to and at least 3 months following the index date. Treatment discontinuation, dose reductions, toxicities, and health care utilization and costs per patient per month (PPPM) were assessed over the full follow-up and the index line of IV paclitaxel/nab-paclitaxel therapy (Index LOT). RESULTS: The sample included 8890 women aged 54.6 (±10.9) years, followed for 18.9 (±13.5) months. Most (82.0%) initiated IV paclitaxel/nab-paclitaxel monotherapy; 83.1% had early discontinuation (<18 weeks of treatment) of the Index LOT. Among the 6943 women eligible for the dose-change analysis, 42.4% evidenced an IV paclitaxel/nab-paclitaxel dose reduction ≥10% during the Index LOT. The most common toxicities during the Index LOT were gastrointestinal upset (30.5%), myelotoxicity (27.0%), infection (26.2%), general symptoms (25.9%), and chemotherapy-induced peripheral neuropathy (22.7%). Over follow-up, 39.7% of women had an inpatient admission and 43.0% had an emergency department visit. The mean of all-cause total costs was $11,991 PPPM, while BC-related total costs were $5320 PPPM. CONCLUSIONS: Many mBC patients initiating IV paclitaxel/nab-paclitaxel experienced dose reductions, toxicities, and/or early discontinuation of the Index LOT, which may limit treatment effectiveness. More tolerable treatments with reduced dosing complexity could improve mBC treatment and help contain costs.

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.