Pegylated liposomal doxorubicin (Doxil®) for metastatic breast cancer:: The Cancer Research Network, Inc., experience

Pegylated liposomal doxorubicin (Doxil(R)) was formulated to improve the safety, profile of doxorubicin. The major toxicities, mucositis and palmar-plantar erythrodysesthesia, are dose and schedule dependent, respectively. Anecdotal experience suggests that a dosage of 40 mg/m(2) every 4 weeks is well tolerated. To evaluate the safety and efficacy of this regimen in women with metastatic breast cancer; we performed a retrospective chart review at a private practice. Forty women received a median initial dose of 42.5 mg/m(2) usually every 4 weeks and a median cumulative dose of 135 mg/m(2) (range: 40-595 mg/m(2)). There were 10 partial responses and,seven patients with stable disease for more than 6 months resulting in a clinical benefit rate of 43% in the intent-to-treat analysis. The median time to progression was 4 months in all patients, 6.5 months in patients who had partial responses, and 10 months in patients who had stable disease for more than 6 months. There was no grade 4 toxicity. The only grade 3 toxicities were leukopenia in seven (18%) patients, mucositis in one (3%), and palmar-plan tar erythrodysesthesia in one (3%). More studies are warranted to confirm our findings, which suggest that pegylated liposomal doxorubicin at a dosage of 40-45 mg/m(2) every 4 weeks is clinically active in, and well tolerated by, women with metastatic breast cancer.