Skip to main content

Table 2 Clinical trials conducted for ultra-orphan drugs and orphan drugs

From: Points to consider: efficacy and safety evaluations in the clinical development of ultra-orphan drugs

  RCT (number of drugs) Dose-response trial (number of drugs) Extension trials (number of drugs)
Japan Outside of Japan Japan Outside of Japan
Parallel-group trial and traditional 3 + 3 design Forced titration trial Optional titration trial Parallel-group trial and traditional 3 + 3 design Forced titration trial Optional titration trial
All ultra-orphan drug 3/43 (7%) 21/43 (49%) 5/43 (12%) 4/43 (3%) 13/43 (30%) 16/43 (37%) 2/43 (5%) 8/43 (19%) 16/43 (37%)
Metabolic drug 1/16 (6%) 11/16 (69%) 1/16 (6%) 1/16 (6%) 6/16 (38%) 7/16 (44%) 1/16 (6%) 4/16 (25%) 10/16 (63%)
Anticancer drug 1/11 (9%) 4/11 (36%) 4/11 (36%) 0/11 (0%) 4/11 (36%) 6/11 (55%) 0/11 (0%) 2/11 (18%) 1/11 (9%)
Biological drug 1/8 (13%) 2/8 (25%) 0/8 (0%) 2/8 (25%) 2/8 (25%) 1/8 (13%) 1/8 (13%) 1/8 (13%) 2/8 (25%)
Others 0/8 (0%) 4/8 (50%) 0/8 (0%) 1/8 (13%) 1/8 (13%) 2/8 (25%) 0/8 (0%) 1/8 (13%) 3/8 (38%)
All orphan drugs other than ultra-orphan drugs 30/88 (34%) 41/88 (47%) 33/88 (38%) 1/88 (1%) 31/88 (35%) 30/88 (34%) 0/88 (0%) 13/88 (15%) 8/88 (9%)
Metabolic drug 8/12 (7%) 3/12 (25%) 5/12 (42%) 0/12 (0%) 7/12 (58%) 3/12 (25%) 0/12 (0%) 3/12 (25%) 2/12 (17%)
Anticancer drug 7/33 (21%) 9/33 (27%) 18/33 (55%) 1/33 (3%) 5/33 (15%) 11/33 (33%) 0/33 (0%) 5/33 (15%) 2/33 (6%)
Biological drug 3/7 (43%) 1/7 (14%) 2/7 (29%) 0/7 (0%) 3/7 (43%) 0/7 (0%) 0/7 (0%) 1/7 (14%) 0/7 (0%)
Others 12/36 (33%) 28/36 (85%) 18/36 (50%) 0/36 (0%) 16/36 (44%) 17/36 (47%) 0/36 (0%) 4/36 (11%) 4/36 (11%)
  1. Classification of clinical trials of the ultra-orphan drugs and orphan drugs other than ultra-orphan drugs for each therapeutic category. Others: drugs other than metabolic drugs, anticancer drugs and biological drugs