| Treatment under study | Study enrollment | Sites | Enrollment, months | RRa | Screened | Screen ratiob |
---|---|---|---|---|---|---|---|
Mild cognitive impairment | Rofecoxib [54] | 1,457 | 46 | 24 | 1.32 | 2,849 | 1.95 |
 | Rivastigmine [55] | 1,018 | 65 | 12 | 1.30 | 1,526 | 1.50 |
 | Two studies of galantamine [56] | 2,057 | 177 | 12 | 0.97 | 2,759 | 1.35 |
 | Donepezil [57] | 270 | 22 | 16 | 0.77 | 588 | 2.18 |
 | Vitamin E and donepezil [38] | 790 | 69 | 23 | 0.49 | 2,264 | 2.87 |
 | TRIMCI study of trifusal [7] | 257c | 29 | 24 | 0.36 | NA | NA |
 | Donepezil [58] | 821 | 91 | 28 | 0.32 | 2,037 | 2.48 |
Mild-to-moderate AD | Dimebon [59] | 183 | 11 | 6 | 2.77 | 230 | 1.26 |
 | Idebenone [60] | 536 | 39 | 12 | 1.14 | 729 | 1.36 |
 | DHA (Joseph Quinn, personal communication) | 402 | 52 | 8 | 0.96 | 555 | 1.39 |
 | AN1792 [61] | 372 | 28 | 16 | 0.83 | NA | NA |
 | Rofecoxib [37] | 351 | 40 | 11 | 0.80 | 474 | 1.35 |
 | Tarenfl urbil [9] | 1,684 | 133 | 21 | 0.60 | 2,408 | 1.43 |
 | Gamma secretase inhibitor [62] | 51 | 6 | 51 | 0.57 | 71 | 1.39 |
 | 1,195 | 100 | 22 | 0.54 | 1,464 | 1.22 | |
 | Bapineuzumab [10] | 234 | 30 | 16 | 0.49 | 317 | 1.35 |
 | Rosiglitazone [65] | 518 | 67 | 17 | 0.45 | 687 | 1.33 |
 | High-dose B vitamin [66] | 409 | 40 | 27 | 0.26 | 601 | 1.47 |
 | Estrogen replacement [6] | 120 | 39 | 32 | 0.10 | 153 | 1.27 |
Moderate-to-severe/Severe AD | Memantine [13] | 404 | 37 | 6 | 1.82 | 589 | 1.46 |
 | Memantine [12] | 252 | 32 | 9 | 0.875 | 345 | 1.37 |
 | Memantine [67] | 350 | 35 | 17 | 0.59 | 547 | 1.56 |
 | Donepezil [5] | 249 | 50 | 18 | 0.28 | 334 | 1.34 |
 | Donepezil [68] | 343 | 91 | 44 | 0.09 | 543 | 1.58 |