Randomized trial of the efficacy and safety of a new oral spray for drug‐induced xerostomia

The aim of this study was to evaluate the efficacy, safety, and tolerability of three formulations of DC161 oral spray, a saliva substitute, and a comparator in relieving drug‐induced xerostomia. This was an open‐label, randomized, 4‐period, cross‐over study in adult subjects with drug‐induced xerostomia and documented hyposalivation. During each of the four 1‐day periods, one product (one of three DC161 formulations or the comparator) was applied at T0 and then at T4h (before a meal). Mouth dryness and related symptoms were evaluated by the subject on a 100‐mm visual analog scale. The primary efficacy criterion was the area under the curve of the dry mouth evaluation (baseline to T4h) after the first application. The oral mucosa was examined by a dental specialist; tolerability and product acceptability were assessed by the subject. Twenty‐four subjects were randomized and completed the study. Despite large variability in data among the products, the selected aqueous formulation – DC161‐DP0292 – reduced the intensity of dryness of mouth at least as well as the comparator; DC161‐DP0292 provided a fast relief and a long‐lasting effect on mouth dryness. Both products improved other symptoms such as swallowing and speaking, even when applied just prior to a meal. DC161‐DP0292 was well tolerated and rated by subjects as providing a slightly higher acceptability of taste/aftertaste, texture, and lubricating effect than the comparator. No clinically relevant signs were reported for any product following the oral examination. DC161‐DP0292 provides fast and long‐acting symptomatic relief and is a relevant new treatment for drug‐induced xerostomia.