Outcomes analysis of an alternative formulation of PEGylated liposomal doxorubicin in recurrent epithelial ovarian carcinoma during the drug shortage era

Background: In response to the critical shortage of Doxil(®), the US Food and Drug Administration (FDA) allowed temporary importation of non-FDA-approved second-generation liposomal doxorubicin, Lipo-Dox(®). Lipo-Dox utilizes a different liposomal particle than Doxil and demonstrates different pharmacokinetic properties. Its use has never been evaluated in a North American population. The objective of this study was to evaluate the efficacy and tolerability of Lipo-Dox at Magee-Womens Hospital, University of Pittsburgh Medical Center, for patients with recurrent epithelial ovarian cancer who were treated during the Doxil shortage.

Methods: Patients treated with Lipo-Dox from January 2012 to December 2012 were identified retrospectively. Disease response was defined radiographically by RECIST (Response Evaluation Criteria in Solid Tumors) or biochemically by CA-125 level if measurable disease was not present. Survival was defined from the start date of Lipo-Dox until the date of progression or death. Toxicity was assessed by the Gynecologic Oncology Group common toxicity criteria.

Results: Eighteen patients with recurrent epithelial ovarian cancer who received Lipo-Dox were identified. These patients had a median of three prior treatment regimens. The median number of Lipo-Dox cycles given was 3.5 (range 1-8). No patients had a complete or partial response. Two patients had stable disease over a mean follow-up of 144.5 days. Fourteen patients had progressive disease, with a median time to progression of 82 days. Progression was based on CA-125 in four patients and RECIST in the remainder. Nine patients died from the disease.

Conclusion: Although this represents a small, pretreated population, there were no clinical responses to Lipo-Dox, raising the question as to whether it is an equivalent substitute for Doxil. Further evaluation is needed, but if confirmed, these findings raise concerns regarding the use of current stocks of Lipo-Dox, as well as the prudence of managing future drug shortages with pharmacologically similar, but clinically untested drugs.