A non-approved formulation of pegylated liposomal doxorubicin — called Lipodox — seems to lead to similar response rates and time to disease progression in ovarian cancer patients as the approved Doxil formulation, results from a single institution show.
The findings suggest that treatment with Lipodox during a shortage of Doxil in 2012 did not result in different therapeutic outcomes for these patients.
The study, “Comparing Outcomes in Patients with Recurrent or Refractory Ovarian Cancer Managed with 1 of 2 Versions of Pegylated Liposomal Doxorubicin at an Academic Medical Center,” was published in the Journal of Hematology Oncology Pharmacy.
Typically, ovarian cancer patients receive surgery and platinum-based chemotherapy as their first-line treatment. But most patients relapse and require additional therapies.
Pegylated liposomal doxorubicin is a kind of chemotherapy that may be given as a second-line option to ovarian cancer patients, regardless of whether they first responded to or failed platinum-based chemotherapy.
The treatment consists of tiny spheres containing the chemotherapeutic agent doxorubicin. The spheres, called liposomes, are made to last longer in circulation and to reach and accumulate in cancer sites more efficiently than doxorubicin, while showing significantly fewer side effects.
In 1995, Doxil became the first pegylated liposomal doxorubicin to be approved by the U.S. Food and Drug Administration. However, its manufacturer, Janssen Oncology, faced several hurdles in late 2011, leading the agency to approve the temporary importation of another formulation approved in India, called Lipodox.
The two formulations are very similar in terms of composition and characteristics, but trials in the U.S. have suggested that patients receiving each medicine have different outcomes.
Thus, University of North Carolina researchers sought to compare the clinical outcomes of ovarian cancer patients who received these formulations after having failed prior treatments.
The study included 40 patients who received Doxil or Lipodox between 2007 and 2014. Of them, 16 had received Doxil only, 20 received Lipodox only, and four had been given the two formulations. The study excluded patients who received the liposomal doxorubicin in combination with any other treatment approaches.
Overall, patients on Doxil only or Lipodox only were similar in terms of age, race, body mass index, and number of prior treatments. They also received a similar number of treatment cycles.
Interestingly, patients on Lipodox had better response rates — 25% versus 6% — and took longer before their disease progressed — 213 days versus 123 days — but the difference was not significant, even after adjusting for the number of unrelated illnesses and responses to platinum-based chemotherapy.
This suggests that the 2012 drug shortage did not affect the outcomes of relapsed or refractory ovarian cancer patients, at least in this institution.
“These data demonstrate no significant difference in [overall response rate] or [time to progression] in patients who received Lipodox compared with those who received Doxil, suggesting that the Doxil drug shortage did not adversely affect treatment outcomes when Lipodox was used as a monotherapy for recurrent or refractory ovarian cancer,” researchers said. “These data support the use of either drug in the event of a future [pegylated liposomal doxorubicin] shortage.”