The percent of closed CAP trials (N=94) that met primary scientific objectives, by rate change and phase of trial. Of the 48 closed Phase 1 trials, 33 had an accrual increase of less than 0.5 patient/month, and 15 increased 0.5–3 patients/month. Of the 46 closed Phase 2 trials, 16 had an accrual increase of less than 0.5 patient/month, 20 increased 0.5–3 patients/month, and 10 increased 3+ patients/month. Of all closed trials, 24% had an accrual rate increase associated with a greater likelihood of meeting their primary scientific objectives (13 Phase 1 and 10 Phase 2 trials).