Long-term benefits
Onset of efficacy was achieved by 15 minutes after dose for both new and rollover patients, and maximal efficacy occurred by 30 minutes. Results were very similar at 24, 36, and 48 weeks. The investigators did not perform statistical analyses.
Across study weeks 1, 12, 24, 36, and 48, between 77% and 92% of new patients and between 65% and 77% of rollover patients self-reported full ON within 30 minutes. “The long-term benefits are maintained over a year as far as the speed of onset and the duration,” Dr. Pahwa said.
Treatment-emergent adverse events occurred in about half of the new and the rollover patient groups in the titration phase and in 71%-81% of patients during the long-term safety phase. Nearly all were mild to moderate in severity.
A large number of participants withdrew from this long-term safety phase because of adverse events – 90 (33%) of new enrollees and 16 (23%) of rollover patients. Only 4% dropped out for lack of efficacy, all in the new enrollee group. Because the sublingual formulation is delivered under the tongue, patients in that group had more oral side effects, Dr. Pahwa said. Otherwise, “the side effects were very similar to the subcutaneous delivery.”
Treatment-emergent adverse events specific to sublingual apomorphine included oral mucosal erythema, lip or tongue swelling, and mouth ulceration (6% to 7% of patients each). Occurring less often were glossodynia, oral candidiasis, stomatitis, and tongue ulceration (2% each).
These were in addition to adverse events typically occurring with subcutaneous apomorphine, which are nausea, falls, dizziness, somnolence, dyskinesia, syncope, and yawning.
There are no head-to-head comparisons of sublingual versus subcutaneous delivery of apomorphine. But based on experience, Dr. Pahwa said, “With the subcutaneous, you have a slightly faster onset of action compared to the sublingual. However, sublingual has a slightly longer duration of benefit.”
He predicted that patients may prefer using an injection for a faster benefit or a sublingual for a slightly longer benefit.
More therapeutic options are welcome
Commenting on the study, Ray Dorsey, MD, professor of neurology at the University of Rochester (N.Y.), said that, for people with more advanced Parkinson’s disease “there’s usually a caregiver who’s injecting someone with an off period, as opposed to sublingual, which seems like a much easier way of administering a drug, especially for people with motor fluctuations.”
He noted that adverse events that led to premature discontinuation from the study “are concerning about the overall tolerability of the drug, which also will be determined in clinical practice, and will likely influence its overall utility.”
However, more therapeutic options are welcome because “the number of people with advanced Parkinson’s disease is going to grow and grow substantially,” he said. “So having therapies that help people with more advanced Parkinson’s disease ... many of whom don’t reach the clinic ... are going to be increasingly important.”
The study was supported by Sunovion. Dr. Pahwa and Dr. Dorsey reported conflicts of interest with numerous sources in industry.
A version of this article originally appeared on Medscape.com.