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William J. Gradishar, MD, FACP, FASCO


Oral Versus Intravenous Paclitaxel Treatment in Metastatic Breast Cancer

By: Kayci Reyer
Posted: Wednesday, September 28, 2022

Findings from a phase III study presented in the Journal of Clinical Oncology suggest that oral paclitaxel may be a safe and effective alternative to intravenous paclitaxel in some patients with metastatic breast cancer. When administered with encequidar, a novel P-glycoprotein pump inhibitor, oral paclitaxel may be more easily absorbed and may allow patients to avoid common intravenous treatment complications, such as neuropathy.

“Potential benefits make oral administration of paclitaxel appealing, including home administration, lack of need for intravenous access, and as oral paclitaxel does not contain Cremophor EL, lack of hypersensitivity reactions or need for corticosteroid and antihistamine prophylaxis,” noted Hope S. Rugo, MD, FASCO, of the University of California San Francisco, and colleagues.

The study included 402 patients from Latin America who had been diagnosed with metastatic breast cancer. Patients were randomly assigned to receive either 205 mg/m2 of oral paclitaxel plus 15 mg of encequidar methanesulfonate monohydrate 3 consecutive days each week (n = 265) or 175 mg/m2 of intravenous paclitaxel once every 3 weeks (n = 137). The oral paclitaxel group experienced a higher confirmed response rate (36% vs. 23%) and longer progression-free (8.4 months vs. 7.4 months) and overall survival (22.7 vs. 16.5 months).

Grade 3 or 4 adverse reaction occurrence rates were comparable between the oral treatment (55%) and intravenous treatment (53%) groups. Neuropathy of at least grade 3 (2% vs. 15%) and alopecia (49% vs. 62%) were less common in the oral treatment group. However, adverse gastrointestinal effects such as nausea, vomiting, and diarrhea, as well as neutropenic problems occurred more often in the oral treatment group, particularly among patients whose liver enzyme levels were high. Treatment-related deaths during the study were slightly higher (3% vs. 0%) with the oral treatment.

Disclosure: For full disclosures of the study authors, visit

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