A Phase II Study of Genexol® ( paclitaxel ) in Metastatic Breast Cancer

Abstract

Purpose: Paclitaxel is a very effective agent in the treatment of breast cancer. Samyang Corporation has developed its own process to produce paclitaxel in a large volume using plant cell culture technology. To evaluate the efficacy and safety of Genexol® in patients with metastatic breast cancer who have failed to respond to standard the rapy, we performed a prospective, multi-center phase II clinical trial.

Materials and Methods: Patients with metastatic breast cancer were included in this study. Enrollees were required to have histologically confirmed breast cancer with bidimensionally measurable metastatic disease. Genexol ® was adminis te red at 175 mg/㎡ as a 3-hour intravenous infusion every 3 weeks. All patients were premedicated with hydrocortisone, pheniramine maleate, and H2 blocker30 minutes priorto paclitaxel. We planned to administer at least 4 courses of paclitaxel unless there was disease progression or unacce ptable toxicity and to continue treatment up to a total of 6 courses in cases of objective response following 4 courses.

Results: The median duration of follow-up was 8.9 (2.07∼13.7) months. Forty-five patients were registered and 43 were eligible. The performance status of patients was ECOG 0∼1 in 39 patients (90.7%) and 2 in 4 (9.3%). The location of metastases at the start of the study were the lung (15 patients), liver (8 patients), lymphnodes (22 patients), and other (7 patients). Among the 40 evaluable patients, 15 patients obtained partial responses(PRs) (37.5%, 95% CI: 22.5∼52.5%). The median duration of response was 11.67 (4.1 ∼11.7) months and the median time to progression was 7.73 (2.8 ∼11.7) months. The median survival time was not reac hed at 13.7 months, and the overall survival rate at 13.7 months was 70.1%. The he matologic toxicity was primarily neutro penia with grade 3 or 4 in 10 patients (23.3%). The grade 3 or 4 non-he matologic toxicities included alopecia (17, 39.5%), mya-lgia (2, 4.7%), neuropathy (2, 4.7%), and pruritus (1, 2.3%). Mild hypersensitivity reaction was observed in 2 patients, although it did not cause withdrawal of the test drug.

Conclusion: The results suggest that the Genexol® in-jection is an effective anticancer for mulation for the treatment of metastatic breast cancer and toxicity is accepta-ble.