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.