The study was funded by Oasmia Pharmaceutical AB, Uppsala, Sweden.
A Randomized Trial Investigating the Efficacy and Safety of Water Soluble Micellar Paclitaxel (Paccal Vet) for Treatment of Nonresectable Grade 2 or 3 Mast Cell Tumors in Dogs
Article first published online: 6 MAR 2012
Copyright © 2012 by the American College of Veterinary Internal Medicine
Journal of Veterinary Internal Medicine
Volume 26, Issue 3, pages 598–607, May-June 2012
How to Cite
Vail, D.M., von Euler, H., Rusk, A.W., Barber, L., Clifford, C., Elmslie, R., Fulton, L., Hirschberger, J., Klein, M., London, C., Martano, M., McNiel, E.A., Morris, J.S., Northrup, N., Phillips, B., Polton, G., Post, G., Rosenberg, M., Ruslander, D., Sahora, A., Siegel, S., Thamm, D., Westberg, S., Winter, J. and Khanna, C. (2012), A Randomized Trial Investigating the Efficacy and Safety of Water Soluble Micellar Paclitaxel (Paccal Vet) for Treatment of Nonresectable Grade 2 or 3 Mast Cell Tumors in Dogs. Journal of Veterinary Internal Medicine, 26: 598–607. doi: 10.1111/j.1939-1676.2012.00897.x
- Issue published online: 2 MAY 2012
- Article first published online: 6 MAR 2012
- Manuscript Accepted: 23 JAN 2012
- Manuscript Revised: 4 JAN 2012
- Manuscript Received: 2 NOV 2011
Effective treatments for dogs with advanced stage mast cell tumors (MCT) remain a pressing need. A micellar formulation of paclitaxel (paclitaxel [micellar]) has shown promise in early-phase studies.
The objective was to demonstrate greater activity for paclitaxel (micellar) compared with lomustine. The null hypothesis was μp = μL (ie, proportion of responders for the paclitaxel [micellar] and lomustine groups, respectively).
Two hundred and fifty-two dogs with advanced stage nonresectable grade 2 or 3 MCT.
Prospective multicenter randomized double-blind positive-controlled clinical trial. The primary endpoint was confirmed overall response rate (CORR) at 14 weeks. A secondary endpoint, biologic observed response rate (BORR), also was calculated. Safety was assessed by the characterization and grading of adverse events (AE).
Overall CORR (7% versus 1%; P = .048) and BORR (23% versus 10%; P = .012) were greater for paclitaxel (micellar) compared with lomustine. Paclitaxel (micellar)-treated dogs were 6.5 times more likely to have a confirmed response and 3.1 times more likely to experience a biologic observed response. The majority of AE with paclitaxel (micellar) were transient and clinically manageable. Twenty-seven dogs (33%) receiving lomustine were discontinued because of hepatopathy compared with 3 dogs (2%) receiving paclitaxel (micellar) (P < .0001; odds ratio 26.7).
Conclusions and Clinical Importance
Paclitaxel (micellar)'s activity and safety profile are superior to lomustine. The addition of an active and novel taxane to the veterinary armamentarium could fill a substantial need and, as its mechanism of action and AE profile do not overlap with currently available TKI, its availability could lead to effective combination protocols.