A Phase 3 Multicenter, Randomized, Double-blind, Placebo-controlled 14-week Study of DS-5565 in Chinese Patients With Diabetic Peripheral Neuropathic Pain

ADPS responder rate

Ratio of Participants Responding to Treatment, as Measured by Average Daily Pain Score (ADPS) Reduction from Baseline. The ADPS is used to determine categorical response rates.

Time frame: at Week 14

Pain Intensity Score Using the Short-Form McGill Pain Questionnaire (SF-MPQ): Visual Analog Scale (VAS)

The VAS, in which the participant rates pain on a 100 mm-long horizontal line, where 0 mm = no pain and 100 mm = worst possible pain.

Time frame: at Week 14

Patient Global Impression of Change

Participants rate their overall impression of how the present pain compares to baseline using a 7-point scale, where 1 = very much improved and 7 = very much worse. Patient Global Impression of Change scores are used to determine categorical responder rates.

Time frame: at Week 14

Average Daily Sleep Interference score (ADSIS)

The sleep interference scores on a scale of 0-10, where 0 = pain did not interfere with sleep to 10 = pain completely interfered with sleep. The weekly ADSIS is based on participants daily sleep interference scores.

Time frame: at Week 14

Medical Outcome Study (MOS) sleep scale

Participants rate their sleep quality during the past 4 weeks in three parts of the questionnaire: Part 1 - The participants rate the average time required to fall asleep, 0-15 minutes = 1, 16-30 minutes = 2, 31-45 minutes = 3, 46-60 minutes = 4, More than 60 minutes = 5. Part 2 - The participants give the number of hours per night for the average hours of sleep per night. Part 3 - The participants using a score of 1 (all of the time) to 5 (none of the time) to rate their sleep disturbance in the following areas: difficulty in falling asleep or remaining asleep, difficulty in staying awake during the day, difficulty in breathing, and snoring during sleep.