PALA in advanced breast cancer. A phase II pilot study by the ECOG.

Thirty-three patients with advanced breast cancer were treated with PALA at a schedule of 1500 mg/m2/day for 5 days every 3 weeks. Time to progression varied from 4-305 days from the start of therapy (median, 49 days) with 3 partial responses (9%) for 231, 180, and 64 days, respectively. Toxicity was considerable, with severe skin and mucosal toxicity occurring in 48% and 39% of cases, respectively. Hematologic toxicity was usually mild. We conclude PALA has limited activity in advanced breast cancer, but may be of advantage in combination chemotherapy because of the relative bone marrow-sparing properties.