A multicenter, double-blind, placebo-controlled trial of the efficacy of oral
cromolyn sodium (200 mg orally four times per day) was conducted in 11 patients with
systemic mastocytosis who had been maintained with the
drug on an individualized compassionate-need basis. Efficacy was measured by physician assessment of overall disease severity based on history and physical examination at specified intervals and by the average daily patient symptom diary scores for each of three
mastocytosis-related symptoms that had previously appeared to be alleviated by the use of this
drug. Efficacy variables were compared for a 4-week baseline period, during which patients received open-labeled
cromolyn sodium, and at 4-week intervals during a 16-week period of random assignment to
cromolyn sodium or placebo. Overall disease severity and symptoms recorded in patient diaries were graded on a scale of 0 (absent) to 5 (incapacitating). The average physician assessment of disease severity and symptom scores of the patients in the placebo-treated group increased significantly during the randomization phase relative to patients in the
cromolyn sodium-treated group, reflecting an exacerbation of symptoms with
drug withdrawal (p less than 0.05 and less than 0.028, respectively). When the symptom scores were analyzed separately for gastrointestinal manifestations of disease (
diarrhea,
abdominal pain,
nausea, and
vomiting),
cromolyn sodium treatment was significantly beneficial relative to placebo (p less than 0.02), whereas the benefit for nongastrointestinal manifestations did not reach statistical significance.