BOSTON—Long-term treatment with interferon beta-1a or glatiramer acetate has the potential to be cost effective and to alter the natural history of relapsing-remitting multiple sclerosis (MS), according to findings from a six-year observational study presented at the 2014 Joint ACTRIMS–ECTRIMS Meeting.
In 4,137 patients with relapsing-remitting MS who were followed for a median of six years, the observed increase in the Expanded Disability Status Scale (EDSS) scores was lower among treated patients than the increase seen in a natural history cohort that served as a comparator group (relative rates, 0.76 using a continuous Markov model and 0.61 using a multilevel model).
Results of Treatment Exceeded Predictions
The observed progression for utility—a quality of life measure derived from the EDSS scores, and the primary outcome of the study—was consistent with this finding (relative rates of 0.58 and 0.56, according to the two models, respectively), said Jacqueline Palace, BM, Consultant Neurologist at the University of Oxford, United Kingdom.
The researchers had predicted that treatment would reduce the observed progression for utility by 38%, compared with the natural history cohort. Data, however, indicated a reduction of about 42%, which was better than predicted, added Dr. Palace. A range of sensitivity analyses that examined the potential for various biases consistently demonstrated better outcomes in the treated patients, compared with the natural history cohort. If sustained over 20 years, the magnitude of the treatment effect observed in this study would be consistent with a predefined cost-effectiveness target of approximately $58,400 per quality-adjusted life-year, said Dr. Palace.
Patients included in this study were adults with a mean age of 38 and a mean age at disease onset of 31. Most participants (76%) were women. Mean disease duration was 7.7 years at baseline, and the patients had a mean of three relapses over the previous two years. Mean baseline EDSS score was 3.06.
The UK’s Risk-Sharing Scheme
“In 2002, the National Institute of Clinical Excellence [NICE], which is the UK body that sets the guidelines that decide [which drugs] should be available under the National Health Service [NHS], concluded that beta-interferon and glatiramer acetate were not cost-effective during the short-term, and thus it recommended that [they] couldn’t be available under the NHS at that stage,” explained Dr. Palace.
The NICE did state, however, that if the drugs’ effects were maintained over the long term, the drugs might be cost effective. The institute invited the Department of Health to “try and find a way to make the drugs available in a cost-effective manner,” said Dr. Palace. “This was the birth of the Risk-Sharing Scheme, and it is a way of providing disease-modifying therapies to patients cost effectively.”
At the start of the scheme, the drug prices were reduced according to a NICE model of cost efficacy. Prices were set at the equivalent of $58,400/quality-adjusted life-year. A price adjustment would have been required to achieve cost effectiveness if the outcomes of the treated patients had been worse than predicted. “We were allowed to reach this target over a 20-year lifespan, and the idea was to monitor a clinical cohort of patients, measuring their EDSS scores,” said Dr. Palace. The natural history dataset was used as a virtual placebo.
The investigation was the largest observational study to measure the effect and cost-effectiveness of interferon beta-1a and glatiramer acetate. The findings provide evidence that the treatment alters the natural history of relapsing-remitting MS, Dr. Palace concluded.