Table 2. Efficacy at Week 12 in Patients With Moderate to Severe Psoriasis in a Phase 2b Study for Zasocitinib.
| End pointa | Placebo (n = 52) | Zasocitinib, once daily | |||
|---|---|---|---|---|---|
| 2 mg (n = 50) | 5 mg (n = 52) | 15 mg (n = 53) | 30 mg (n = 52) | ||
| PASI 75 (primary end point), No. (%) | 3 (6) | 9 (18) | 23 (44) | 36 (68) | 35 (67) |
| P value vs placebo | NA | .05 | <.001 | <.001 | <.001 |
| Proportion difference vs placebo, % (95% CI)b | NA | 12 (0 to 25) | 39 (24 to 53) | 62 (48 to 76) | 62 (47 to 76) |
| PASI 90, No. (%) | 0 | 4 (8) | 11 (21) | 24 (45) | 24 (46) |
| Proportion difference vs placebo, % (95% CI)b | NA | 8 (1 to 16) | 21 (10 to 32) | 45 (32 to 59) | 46 (33 to 60) |
| PASI 100, No. (%) | 0 | 1 (2) | 5 (10) | 8 (15) | 17 (33) |
| Proportion difference vs placebo, % (95% CI)b | NA | 2 (−2 to 6) | 10 (2 to 18) | 15 (5 to 25) | 33 (20 to 45) |
| PGA score of 0 or 1, No. (%) | 2 (4) | 5 (10) | 14 (27) | 26 (49) | 27 (52) |
| Proportion difference vs placebo, % (95% CI)b | NA | 6 (−4 to 16) | 23 (10 to 36) | 45 (31 to 60) | 48 (34 to 63) |
Abbreviations: NA, not applicable; PASI, Psoriasis Area and Severity Index; PASI 75, at least 75% improvement in PASI; PASI 90, at least 90% improvement in PASI; PASI 100, 100% improvement in PASI; PGA, Physician’s Global Assessment.
The PASI is a composite score ranging from 0 to 72 that considers the degree of erythema, induration/infiltration, and desquamation (each scored from 0 to 4 separately) for each of 4 body regions, with adjustments for the percentage of the BSA involved for each body region and proportion of the body region to the whole body. For PASI calculation, the 4 main body regions were assessed: the head, the trunk, and the upper and lower extremities, corresponding to 10%, 20%, 30%, and 40% of the total body area, respectively. The area of psoriatic involvement of these 4 main regions was given a numerical value: 0 indicating no involvement, 1 indicating less than 10% psoriatic involvement, 2 indicating 10% to less than 30% psoriatic involvement, 3 indicating 30% to less than 50% psoriatic involvement, 4 indicating 50% to less than 70% psoriatic involvement, 5 indicating 70% to less than 90% psoriatic involvement, and 6 indicating 90% to 100% psoriatic involvement.27 The PGA score is a 5-point morphological assessment of overall disease severity. For the purposes of this study, the PGA score ranged from 0 to 4, with 0 representing clear skin and 4 representing severe disease.
Proportion differences for achievement of PASI 75, PASI 90, PASI 100, and a PGA of 0 or 1 were calculated using the Mantel-Haenszel method. The P value for the primary end point was derived from a Cochran-Mantel-Haenszel test, with previous treatment with biologics included as a stratification factor, and compared with the proportion of patients achieving PASI 75 in each dose group of zasocitinib vs placebo. P values for secondary end points were not reported because these values have not been adjusted for multiple comparisons; 95% CIs are unadjusted.