Efficacy of Ritlecitinib (PF-06651600) in Patients With Alopecia Totalis and Alopecia Universalis:  
Post Hoc Analysis of the ALLEGRO Phase 2b/3 Study

Xingqi Zhang,1 Nina Magnolo,2 Masato Mizuashi,3 Natasha Mesinkovska,4 Jerry Shapiro,5 Fan Zhang,6 Urs Kerkmann,7 Ernest Law,8 Robert Wolk,6 Gregor Schaefer7

1The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China; 2University Hospital Münster, Münster, Germany; 3Tohoku University Graduate School of Medicine, Sendai, Japan; 4School of Medicine, University of California, Irvine, CA, USA;  
5New York University Grossman School of Medicine, New York, NY, USA; 6Pfizer Inc, Groton, CT, USA; 7Pfizer Pharma GmbH, Berlin, Germany; 8Pfizer Inc, New York, NY, USA

BACKGROUND
• Alopecia areata (AA) is an autoimmune disease that has an underlying immuno-inflammatory pathogenesis and is characterized 

by nonscarring hair loss ranging from small patches to complete scalp, face, and/or body hair loss1

• Spontaneous hair regrowth can occur in AA; however, it is unlikely to occur in extensive forms of AA, including alopecia totalis 
(AT; complete loss of scalp hair) and alopecia universalis (AU; complete loss of scalp, face, and body hair)2 

• The Severity of Alopecia Tool (SALT) assesses the extent of scalp hair loss with scores ranging from 0 (no scalp hair loss) to 100 
(complete scalp hair loss); patients with AT and AU have a SALT score of 1003

• Ritlecitinib, an oral JAK3/TEC inhibitor, demonstrated efficacy and safety in patients aged ≥12 years with AA in the ALLEGRO 
phase 2b/3 trial (NCT03732807)4

OBJECTIVE
• To evaluate the efficacy of ritlecitinib at Weeks 24 and 48 in patients with AT and AU in the ALLEGRO phase 2b/3 study

METHODS
Study design 
• The ALLEGRO phase 2b/3 trial was an international, randomized, double-blind, placebo-controlled, combined dose-ranging and 

pivotal phase 2b/3 study (Figure 1) 

• Patients received once daily ritlecitinib (± a 4-week 200-mg daily loading dose): 200/50 mg, 200/30 mg, 50 mg, 30 mg,  
10 mg (10 mg assessed for dose ranging only), or placebo for 24 weeks

• During the 24-week extension, ritlecitinib groups continued receiving their 50, 30, or 10 mg maintenance doses, and patients 
initially assigned to placebo switched to 200/50 or 50 mg daily

Key eligibility criteria
• Patients aged ≥12 years with a diagnosis of AA and ≥50% scalp hair loss, including those with AT and AU, and a current  

AA episode duration of 6 months to 10 years

Figure 1. Study design 

Rit 200 mg QD

Rit 200 mg QD 

Rit 50 mg QD

Rit 30 mg QD

Rit 10 mg QD

Placebo

Placebo

Rit 50 mg QD

Rit 30 mg QD

Rit 50 mg QD

Rit 30 mg QD

Rit 10 mg QD

Placebo

Placebo

Rit 50 mg QD

Rit 30 mg QD

Rit 50 mg QD

Rit 30 mg QD

Rit 10 mg QD

Rit 200/50 mg QD

Rit 50 mg QD

Placebo-Controlled (24 Weeks)

Study Week

Extension
(24 Weeks)

Maintenance
(20 Weeks)

Loading
(4 Weeks)

BL 2 4 8 12 18 26 28 34 40 4824

S
cr

ee
ni

ng

R
an

do
m

iz
at

io
n

Screening and 
Randomization 

(35 Days)

n=132

n=66
n=65
n=63

n=130
n=132

n=130

BL, Baseline; QD, once daily; Rit, ritlecitinib.

Outcomes
• This study assessed the proportion of patients in each subgroup with response based on a SALT score of ≤20 (≤20% scalp 

without hair) and a Patient Global Impression of Change (PGI-C) response of “moderately improved” or “greatly improved” at 
Weeks 24 and 48

 - PGI-C is a self-reported, single-item scale on which patients rate the improvement or worsening of AA compared with AA at 
the start of the study, using a scale of 7 responses ranging from “greatly improved” to “greatly worsened”

Statistical analysis
• In this post hoc analysis, patients were stratified by type of AA at baseline and were divided into 4 subgroups: AT/AU, AT, AU,  

and non-AT/non-AU 

 - The AT/AU subgroup comprised all patients with a SALT score of 100 (complete scalp hair loss) at baseline 

 - Patients in the AT or AU groups had a SALT score of 100 at baseline and a clinical diagnosis of AT or AU, respectively,  
by the investigator

• Descriptive analyses were used to evaluate the proportion of patients with SALT ≤20 and PGI-C response by AT/AU status 

• 95% CIs were calculated based on normal approximation

Efficacy by AT/AU status at Weeks 24 and 48
• In all AA subgroups, SALT ≤20 response rates generally increased between Weeks 24 and 48 (Figure 2)

 - Across all ritlecitinib treatment groups (200/50 mg, 200/30 mg, 50 mg, 30 mg), SALT ≤20 response rates were highest in the 
non-AT/non-AU group at Weeks 24 and 48 

 - Placebo response rates were low across all subgroups at Week 24; a substantial proportion of patients who switched to 
ritlecitinib 200/50 or 50 mg had a SALT ≤20 response by Week 48

 - At Week 48, the proportion of patients with a SALT ≤20 response was generally similar across the AT/AU, AT,  
and AU subgroups

• Higher proportions of patients with non-AT/non-AU had a PGI-C response of "moderately improved" or "greatly improved" in all 
treatment groups vs patients with AT/AU, AT, or AU at Week 24, and response rates generally improved through Week 48 (Figure 3)

 - At Week 48, up to 49%, 50%, and 64% of patients had a PGI-C response in the AT/AU, AT, and AU subgroups, respectively,  
vs up to 73% in the non-AT/non-AU subgroup

Presented at the 2022 Fall Clinical Dermatology Conference; October 20 - 23, 2022; Las Vegas, Nevada

REFERENCES
1. Islam N, et al. Autoimmun Rev. 2015;14:81-89. 
2. Delamere FM, et al. Cochrane Database Syst Rev. 2008;16:CD004413.
3. Olsen EA, et al. J Am Acad Dermatol. 2018;79:470-478.
4. King B, et al. Presented at: EADV 2021.

DISCLOSURES
This study was sponsored by Pfizer Inc. 

F.Z., U.K., E.L., R.W., and G.S. are employees of Pfizer and hold stock or stock options in Pfizer. X.Z. declares no conflicts of interest. N.M. reports honoraria for participation in advisory boards from and being a speaker and/or for consultant for AbbVie, Almirall, 
BMS, Boehringer Ingelheim, Celgene, Eli Lilly, Janssen, LEO Pharma, Novartis, Pfizer, and UCB. M.M. is a principal clinical trial investigator for Pfizer. N.M. has provided professional services for AbbVie, Arcutis, Arena, BMS, Concert, Galderma, Merz, Eli Lilly, 
Kadmon, Novartis, and Pfizer and has received honoraria from Eli Lilly, Pfizer, Nutrafol, Concert, and Arena. J.S. provides consultancy for Pfizer and Eli Lilly and is a clinical trial investigator for Pfizer.

Third-party medical writing assistance, provided by Health Interactions, Inc, was funded by Pfizer Inc.

RESULTS 
• Of the 718 patients randomized, 151 (21%) had AT and 147 (20%) had AU; patients with AT and AU were evenly distributed across 

treatment groups (Table 1)

Table 1. Baseline characteristics 

Ritlecitinib QD

200/50 mg 
(n=132)

200/30 mg 
(n=130)

50 mg  
(n=130)

30 mg  
(n=132)

10 mg  
(n=63)

Placebo* 
(n=131)

Age

Mean (SD), years 34.5 (15.0) 33.7 (13.8) 32.4 (13.4) 33.7 (14.8) 34.3 (13.9) 34.0 (15.0)

12-17 years, n (%) 20 (15.2) 19 (14.6) 18 (13.8) 20 (15.2) 9 (14.3) 19 (14.5)

≥18 years, n (%) 112 (84.8) 111 (85.4) 112 (86.2) 112 (84.8) 54 (85.7) 112 (85.5)

Female, n (%) 81 (61.4) 85 (65.4) 71 (54.6) 80 (60.6) 43 (68.3) 86 (65.6)

White, n (%) 92 (69.7) 90 (69.2) 79 (60.8) 91 (68.9) 42 (66.7) 94 (71.8)

Type of AA, n (%)     

AT/AU† 60 (45.5) 60 (46.2) 60 (46.2) 61 (46.2) 29 (46.0) 60 (45.8)

AT‡ 25 (18.9) 34 (26.2) 30 (23.1) 26 (19.7) 12 (19.0) 24 (18.3)

AU‡ 26 (19.7) 21 (16.1) 24 (18.5) 29 (22.0) 13 (20.6) 34 (26.0)

Non-AT/non-AU 72 (54.5) 70 (53.8) 70 (53.8) 71 (53.8) 34 (54.0) 71 (54.2)

Baseline SALT score, mean (SD)

All patients 90.3 (15.1) 90.5 (14.3) 90.3 (14.7) 90.0 (15.1) 88.3 (16.9) 93.0 (11.5)

Non-AT/non-AU† 82.2 (16.5) 82.4 (15.4) 82.0 (15.9) 81.5 (16.3) 78.3 (17.6) 87.0 (12.9)

Duration of current AA episode, mean (SD), years 3.4 (2.93) 3.4 (2.89) 3.2 (2.67) 3.6 (2.82) 3.3 (2.65) 3.2 (2.65)

AA, alopecia areata; AT, alopecia totalis; AU, alopecia universalis; QD, once daily; SALT, Severity of Alopecia Tool. 
*Patients received placebo for 24 weeks and then switched to ritlecitinib 200/50 mg or 50 mg QD. 
†All patients in the AT/AU category had a SALT score of 100 at baseline. This subgroup includes patients who had received a clinical diagnosis of AT or AU plus those with a   
 baseline SALT score of 100 without a clinical diagnosis of AT or AU. 
‡Patients in the AT or AU category had a SALT score of 100 at baseline and received a clinical diagnosis of AT or AU, respectively, by the investigator. Patients with AT or AU  
were included in the AT/AU category.

Figure 2. Response based on SALT ≤20 at Weeks 24 and 48 by AT/AU status

AA, alopecia areata; AT, alopecia totalis; AU, alopecia universalis; QD, once daily; SALT, Severity of Alopecia Tool. Percentages and error bars (95% CIs) are shown for SALT ≤20 response at Week 48.

Figure 3. Response based on PGI-C score* at Weeks 24 and 48 by AT/AU status

AA, alopecia areata; AT, alopecia totalis; AU, alopecia universalis; PGI-C, Patient Global Impression of Change; QD, once daily. 
*PGI-C response was defined as “moderately improved” or “greatly improved”. Percentages and error bars (95% CIs) are shown for PGI-C response at Week 48.

CONCLUSIONS
• Ritlecitinib demonstrated clinical and patient-reported efficacy across all AA subgroups, including in patients with more 

extensive forms of AA (AT and AU)

• Higher SALT ≤20 response rates were observed in patients with less extensive AA (non-AT/non-AU) than in patients  
with AT/AU, AT, or AU over 48 weeks of ritlecitinib treatment 

• While SALT ≤20 responses were lower in patients with AT/AU compared to those without AT/AU, a substantial proportion of patients with AT/AU  
still reported moderate or great improvement in their AA while receiving ritlecitinib, suggesting that many patients experienced meaningful 
benefit without achieving SALT ≤20 response

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p/vqkur0904pp3n1v5

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