This study reports on the initial experience prescribing fingolimod to patients at an academic multiple sclerosis (MS) clinic, including first-dose observation (FDO) and three-month follow-up data. The authors found that fingolimod was well tolerated during FDO, and adverse events were self-limited.
Adverse events were similar to those described in clinical trials but the discontinuation rate was higher, with three patients (0.9 percent) discontinuing due to macular edema. None of the patients with macular edema were symptomatic, which differed from clinical trials in which half of the one percent of patients with macular edema were symptomatic.
The authors reviewed medical records of 317 MS patients prescribed fingolimod from September 2010 to July 2011. Fingolimod was most frequently used in patients with relapsing-remitting MS (80.8 percent) and as a second line agent (96.5 percent). In the current study, 3.8 percent of patients had diabetes and one of the three patients with macular edema had diabetes.
FDO was uneventful in 96.8 percent of patients. Adverse drug events at FDO included symptomatic bradycardia in 0.9 percent, chest tightness in 0.6 percent and hypertension in 0.3 percent.
At three months, fingolimod was discontinued in 9.5 percent of patients due to headache (1.2 percent), macular edema (0.9 percent), nausea (0.9 percent) or hypertension (0.6 percent).
The rate of macular edema at the three-month follow-up visit was similar to the rate in MS phase III clinical trials: 0.3 percent of patients on 0.5 mg fingolimod and 1 percent of patients on 1.25 mg of fingolimod. Macular edema typically occurred four months after initiation of fingolimod in clinical trials and caused visual symptoms in approximately half of the cases.
Patients with diabetes were excluded from phase III MS clinical trials due to their increased risk of macular edema. The authors also note that macular edema appears to occur at higher rates in patients with comorbid uveitis and with increasing age.
All patients who developed macular edema in the current study were older than age 50. The fact that they were all asymptomatic at the time of detection highlights the need for routine screening for macular edema at three to four months. Periodic additional ophthalmologic follow-up may be reasonable in patients with diabetes mellitus who are older than age 50, given the potential for increased risk in this population.
While this study is limited by its short follow-up, it highlights FDO information of patients starting fingolimod who otherwise would have been excluded from clinical trials: those with comorbid diabetes, cardiac disease, asthma and chronic obstructive pulmonary disease.