Stem-cell transplants in multiple sclerosis will not threaten the current drug therapeutic market despite the extraordinary efficacy observed in a recent trial, neurologists said on the side lines of the recent ECTRIMS conference in London, UK.
Earlier this year an investigator-sponsored Phase II trial of immune-ablation and autologous heamopoietic stem-cell transplantation (aHSCT), garnered significant media attention due to the long term efficacy observed in a large number of the participants. However, experts cautioned that given the danger associated with the treatment, it was unlikely ready for usage in the general population and would be restricted to a last line option in the most severe patients. In the trial, one patient out of 24 (4%) died due to complications associated with the transplant.
The MS market is divided into high efficacy therapies, such as Sanofi’s (EPA:SAN) Lemtrada (alemtuzumab) and Biogen’s (NASDAQ:BIIB) Tysabri (natalizumab) and lower efficacy therapies such as Teva’s (NYSE:TEVA) Copaxone and Biogen’s Avonex (interferon beta-1a). Lemtrada which was approved in November 2014 by the FDA, generated global sales of USD 275m in 2015 and has projected peak sales of USD 1.2bn. Tysabri, which has been marketed since 2004, generated global sales of USD 1.9bn in 2015. Current MS leaders, Avonex and Copaxone, generated global sales of USD 2.6bn and USD 4bn respectively.
There will be continuing trials testing aHSCT in patients, however, it is unlikely to replace other standard of care treatments, said Dr Thomas Berger, Vice-Director, Clinical Department of Neurology, Innsbruck Medical University, Austria. The prevailing view at this time is that aHSCT is a highly efficacious and durable treatment with some heavily front-loaded safety issues at the time of immune-ablation, said Dr Jeffrey Cohen, director, Cleveland Clinic Mellen Cente, Ohio. There is clearly a great benefit from this treatment but the mortality risk is significant, said Dr Tomas Kalincik, Neurologist and Senior Research Fellow, Melbourne Brain Center, University of Melbourne, Australia.
In the procedure, stem cells are used to rescue patients from the heavy and potentially lethal chemotherapy, which essentially eradicates the immune system, explained Berger. Whilst the mortality rate for the procedure remains high, the treatment won’t be used frequently and will be reserved as a final option for patients with the most aggressive disease, said Dr Marinella Clerico, neurologist, University Hospital San Luigi Gonzaga, Turin, Italy.