| Literature DB >> 33156550 |
Mohamed-Eslam F Mohamed1, Sathej Gopalakrishnan2, Henrique D Teixeira3, Ahmed A Othman1.
Abstract
Upadacitinib is a selective Janus kinase 1 inhibitor that was recently approved for treatment of rheumatoid arthritis and is currently being evaluated for treatment of several other autoimmune diseases, including atopic dermatitis (AD). The relationships between upadacitinib plasma exposure and efficacy (assessed as Eczema Area Severity Index [EASI]-75, EASI-90, and Investigator Global Assessment [IGA] 0/1) in subjects with moderate to severe atopic dermatitis were characterized using the data from 167 subjects who were enrolled in a phase 2b dose-ranging study. Subjects were randomized to receive once daily doses of monotherapy treatment with upadacitinib extended-release 7.5, 15, or 30 mg or placebo for 16 weeks. Logistic regression models were developed and utilized to simulate efficacy for upadacitinib with an approximate phase 3 sample size. Based on exposure-response models, 15 mg once daily is predicted to achieve EASI-75, EASI-90, and IGA 0/1 responses in 48%, 26%, and 29% of subjects, respectively, compared with placebo responses of 9%, 2%, and 2%, respectively, whereas 30 mg once daily is predicted to provide an additional approximately 20% greater efficacy for these end points relative to 15 mg once daily. These analyses supported the selection of upadacitinib doses that are being evaluated in ongoing global phase 3 studies in atopic dermatitis.Entities:
Keywords: JAK inhibitor; Upadacitinib; atopic dermatitis; exposure-response; immunology; pharmacometrics
Mesh:
Substances:
Year: 2020 PMID: 33156550 PMCID: PMC8049015 DOI: 10.1002/jcph.1782
Source DB: PubMed Journal: J Clin Pharmacol ISSN: 0091-2700 Impact factor: 3.126
Summary of Demographic and Other Intrinsic Factors for Subjects Included in the Analyses Data Sets
| Characteristic | All Subjects (n = 167) | |
|---|---|---|
| Age (years) | n | 167 |
| Mean (SD) | 39.9 (15.8) | |
| Median | 37.0 | |
| Min‐Max | 18.0‐75.0 | |
| Body weight (kg) | n | 167 |
| Mean (SD) | 79.2 (19.5) | |
| Median | 76.5 | |
| Min‐Max | 45.0‐150 | |
| Sex | Male | 104 (62%) |
| Female | 63 (38%) | |
| Asian race | No | 129 (77%) |
| Yes | 38 (23%) | |
| Percentage of body surface area affected by atopic dermatitis | n | 167 |
| Mean (SD) | 46.3 (22.5) | |
| Median | 42.0 | |
| Min‐Max | 12.0‐99.0 | |
| EASI Score at baseline | n | 167 |
| Mean (SD) | 30.9 (13.6) | |
| Median | 26.4 | |
| Min‐Max | 16.0‐69.6 | |
| Disease duration at baseline (years)a | n | 166b |
| Mean (SD) | 25.9 (16.8) | |
| Median | 23.5 | |
| Min‐Max | 0.0‐72.0 |
SD, standard deviation.
aDisease duration was rounded to whole years. Minimum disease duration was 8 days.
bBaseline disease duration was missing for 1 subject, and baseline for NK cells was missing for 6 subjects.
Upadacitinib Model‐Predicted (Median [5th to 95th Percentiles]) Plasma Exposures During a Dosing Interval at Steady State for the Extended‐Release Regimens Evaluated in the atopic dermatitis Phase 2 Study
| 7.5 mg Once Daily | 15 mg Once Daily | 30 mg Once Daily | |
|---|---|---|---|
| Cavg, ng/mL | 7.8 (4.7‐15.7) | 13.7 (9.5‐25.5) | 29.7 (19.2‐58.6) |
| Cmax, ng/mL | 22.6 (15.7‐39.1) | 41.2 (27.7‐65.8) | 84.8 (59.7‐135) |
| Cmin, ng/mL | 2.0 (0.56‐6.2) | 2.7 (1.2‐11.3) | 6.6 (2.1‐22.1) |
Figure 1Observed and predicted EASI and IGA responses (NRIs) for atopic dermatitis subjects in week 16 versus upadacitinib average concentration. The solid blue line denotes median predicted probability, whereas the band indicates the 95% confidence interval (CI) of predictions. The observed data are binned into placebo and upadacitinib Cavg quartiles (black dots denoting median and error bars the binomial CIs). The red, green, and blue vertical lines at the bottom represent model‐predicted median Cavg over a dosing interval at steady state for 7.5, 15, and 30 mg doses, whereas the hinges in the box plot represent the 25th and 75th percentiles, and the horizontal lines denote the lowest or highest value within 1.5 times the interquartile range from the lower or upper hinge, respectively. Observations above and below 1.5 times the interquartile range are denoted as individual dots.
Parameter Estimates of the Logistic Regression Models for the Relationships Between Upadacitinib Plasma Cavg and the Probability of Achieving Different Efficacy End Points (NRI) in Week 16
| End Point | Parameter | Estimate (%RSE) | 95%CI |
|---|---|---|---|
| EASI‐75 | Intercept | −2.43 (23%) | −3.5 to −1.35 |
| Emax | 5.35 (17% | 3.06 to 9.36 | |
| EC50 (ng/mL) | 18.6 (26% | 4.28 to 81.1 | |
| EASI‐90 | Intercept | −3.87 (26%) | −5.85 to −1.9 |
| Emax | 6.2 (13% | 3.86 to 9.95 | |
| EC50 (ng/mL) | 18.1 (29% | 3.5 to 93.7 | |
| IGA 0/1 | Intercept | −4.03 (28%) | −6.21 to −1.84 |
| Emax | 5.78 (12% | 3.78 to 8.83 | |
| EC50 (ng/mL) | 12.8 (31% | 2.77 to 59.3 |
The parameter was estimated on a transformed exponential scale and the %RSE is given on this scale.
Simulated Percentage of Subjects Assuming Phase 3 Sample Size Who Achieve Different Efficacy End Points (NRI) in Week 16
| Dose Group | Placebo | 7.5 mg Once Daily | 15 mg Once Daily | 30 mg Once Daily |
|---|---|---|---|---|
| EASI‐75 | 9 (3‐17) | 32 (22‐40) | 48 (36‐60) | 68 (54‐81) |
| [10] | [29] | [52] | [69] | |
| EASI‐90 | 2 (0‐10) | 14 (10‐23) | 26 (17‐36) | 48 (31‐62) |
| [2] | [14] | [26] | [50] | |
| IGA 0/1 | 2 (0‐11) | 17 (10‐27) | 29 (19‐40) | 49 (31‐63) |
| [2] | [14] | [31] | [50] |
Note: Results represent median percentage of subjects (5th and 95th percentiles) from 200 replicates with 270 subjects/dose group in each replicate [observed percentage of subjects].