Tapinarof Inhibits the Formation, Cytokine Production, and Persistence  
of Resident Memory T Cells In Vitro

Nathan Mooney,1 Jessica E. Teague,1 Ahmed E. Gehad,1 Kimberly McHale,2 David S. Rubenstein,2 Rachael A. Clark1
1Brigham and Women’s Hospital, Boston, MA, USA; 2Dermavant Sciences, Morrisville, NC, USA 

 BACKGROUND 
■ Tapinarof (VTAMA®; Dermavant Sciences, Inc.) is a first-in-class, non-steroidal, topical, 

aryl hydrocarbon receptor (AhR) agonist approved by the Food and Drug Administration 
for the treatment of plaque psoriasis in adults,1 and under investigation for the treatment 
of psoriasis in children down to 2 years of age and for atopic dermatitis in adults and 
children down to 2 years of age

■ Tapinarof cream 1% once daily treatment has been observed to induce a remittive effect 
in the phase 3 psoriasis long-term extension trial, PSOARING 32 

  –  Patients who achieved Physician Global Assessment (PGA) of 0 (clear) after topical 
tapinarof treatment remained clear for a median of ~4 months after therapy was 
discontinued, defined as a PGA of 0 or 1 (almost clear) while off therapy after achieving 
complete disease clearance (Figure 1)2

■ Resident memory T cells (T
RM

) drive lesional recurrence in psoriasis and are affected by 
AhR signaling3–5

■ AhR binds to toxins, endogenous and exogenous ligands, and has published effects on  
T cell differentiation6,7

Figure 1. Duration of Remittive Effect Among Patients Entering PSOARING 3 with a 
PGA Score of 0 (Clear): Maintenance of a PGA Score of 0 or 1 (Almost Clear) While  
Off Therapy

0

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0 25 50 75 100 125 150 175 200 225 250 275 300 325

79

Number of 
patients at risk

Overall 76 58 48 44 33 29 23 19 17 17 17 15 Trial
end

P
ro

b
a

b
il

it
y

 o
f 

d
is

e
a

se
 w

o
rs

e
n

in
g

Time (days)

Median time to PGA ≥2
115 days

Overall (n=79)

PGA, Physician Global Assessment.

 OBJECTIVE
■ To study the effect of tapinarof on T

RM
 using in vitro assays 

 MATERIALS AND METHODS

T Cell Activation and Cytokine Production Assessment
■ Blood-derived T cells were cultured with anti-CD2/CD3/CD28 activation beads for 1 week
  –  Activation was assessed at 24 hours (CD69 expression) 
  –  Expression of other markers (CD69, CD103, etc.) was determined after 1 week  

of culture 
■ Cytokine production was quantified using intracellular cytokine staining and flow 

cytometry analysis
■ An antigen-presenting cell assay was used to quantify the T

RM
 survival niche in skin cells

■ Dermatomed samples of human skin were cultured in Th17-skewing conditions8 for  
3 days, and analyzed for T cell activation (CD107a) and entry into the cell cycle (Ki-67) by 
immunostaining

 RESULTS 

Suppression of Early T Cell Activation and Induction of CD39 Expression
■ A significantly lower proportion of tapinarof-treated T cells (both CD4+ and CD8+ cells; 

P=0.012) were activated compared with control, following treatment for 24 hours  
(Figure 2A)

■ Numerically higher proportions of CD4 cells and significantly higher proportions of CD8 
cells (P=0.002) expressed CD39 following tapinarof treatment compared with control 
after 1 week (Figure 2B)

Figure 2. Tapinarof Significantly Suppressed Early T Cell Activation After 24 Hours 
and Induced CD39 Expression After 1 Week of Culture

Co
nt

ro
l

Ta
pi

na
ro

f

CD4+
A

P=0.012

0

10

20

30

Co
nt

ro
l

Ta
pi

na
ro

f

CD8+

P=0.012 P=0.002

0

10

20

30

40

A
ct

iv
a

te
d

 T
 c

e
ll

s,
 %

CD
8
+

CD
4
+

B

–75

–50

–25

0

25

C
h

a
n

g
e

, 
%

CD
4

CD
8

0

20

60

40

80

P
o

si
ti

v
e

, 
%

Control

Individual donor/data point

Tapinarof

In Vitro Generation of T
RM

 
■ CD4 T

RM
 formation was significantly reduced (CD69+, P=0.045 and CD69+CD103+, 

P=0.027) and there was a trend for reduced CD8 T
RM

 formation with tapinarof compared 
with control (Figure 3) 

Figure 3. Tapinarof Suppressed CD4 T
RM

 Formation in an In Vitro Culture System

Co
nt

ro
l

Ta
pi

na
ro

f

CD4 T
RM

A

–200

400

200

0

600

CD69+

P=0.045

Co
nt

ro
l

Ta
pi

na
ro

f

–50

100

50

0

150

CD69+CD103+ CD69+CD103+

P=0.027

C
e

ll
s/

1
0

0
0

 v
ia

b
le

, 
n

B

–100

0

–50

50

69+
69+/
103+

C
h

a
n

g
e

 i
n

 n
u

m
b

e
r 

o
f 

C
D

4
 T

R
M
, 

%

Co
nt

ro
l

Ta
pi

na
ro

f

C

–100

200

100

0

300

Co
nt

ro
l

Ta
pi

na
ro

f

–500

500

0

1000

C
e

ll
s/

1
0

0
0

 v
ia

b
le

, 
n

D

–100

0

–50

50

C
h

a
n

g
e

 i
n

 n
u

m
b

e
r 

o
f 

C
D

8
 T

R
M
, 

%

CD8 T
RM

CD69+

69+
69+/
103+

Control

Individual donor/data point

Tapinarof

T
RM

, resident memory T cell.

In Vitro Survival
■ The antigen-presenting cells used IL-32β produced by T cells to induce differentiation of 

monocytes into OX40L/CD40L-expressing dendritic cells (DC), which may support T cell 
survival in vitro (Figure 4A)

■ Tapinarof did not inhibit the formation of DC (not shown) but blocked T cell survival, 
suggesting it may interfere with DC:T cell signaling (Figure 4B)

Figure 4. Tapinarof Suppressed T Cell Survival in an In Vitro Antigen-Presenting 
Cell: T Cell Support Assay

2000

4000

6000

8000

10,000

0 14 21

IL-32β

Days in culture

Monocytes Co-stimulatory
DC

IL-32β

CD40L CD40LOX40L OX40L

T cell survival
in culture

V
ia

b
le

 T
 c

e
ll
s,

 n

A B

IL-32β + DMSO control
IL-32β + Tapinarof

No IL-32β

DC, dendritic cells; DMSO, dimethyl sulfoxide; IL, interleukin.

Cytokine Production by In Vitro Generated T
RM

■  IL-17A, TNFα, and IFNγ production was reduced among in vitro generated T
RM

 (Figure 5)
■ Non T

RM
: CD69–CD103–; SP T

RM
: CD69+CD103–; DP T

RM
: CD69+CD103+ 

Figure 5. Tapinarof Suppressed Cytokine Production in CD4 and CD8 T
RM

 Cells 
Generated In Vitro 

N
on

 T R
M

SP
 T R

M

DP
 T R

M

TapinarofControl

CD4+ T cellsA

0

20

10

30 IL-17A

N
on

 T R
M

SP
 T R

M

DP
 T R

M

40

80
90

60
50

70

100 TNFα

TNFαC

C
D

4
 T

 c
e

ll
s,

 %

N
on

 T R
M

SP
 T R

M

DP
 T R

M

0

80

20
40
60

100 TNFα

C
D

8
 T

 c
e

ll
s,

 %

N
on

 T R
M

SP
 T R

M

DP
 T R

M

0

20

10

30 IL-22

N
on

 T R
M

SP
 T R

M

DP
 T R

M

0

40

20

60 IFNα

C
D

4
 T

 c
e

ll
s,

 %

0

100

50

150
CD69+

C
e

ll
s,

 %

C
D

4
 T

 c
e

ll
s,

 %
C

D
4

 T
 c

e
ll

s,
 %

N
on

 T R
M

SP
 T R

M

DP
 T R

M

0

60

20

40

80 IFNα

C
D

8
 T

 c
e

ll
s,

 %

CD8+ T cellsB

SP
Control

SP
Tapinarof

0

100

50

150
CD69+ CD103+

C
e

ll
s,

 %

DP
Control

DP
Tapinarof

40

80
70
60
50

90
Non T

RM

P=0.018

C
e

ll
s,

 %

DN
Control

DN
Tapinarof

IL-17AD

–10

20

10

0

30
CD69+

C
e

ll
s,

 %

SP
Control

SP
Tapinarof

–20

30
20
10

–10
0

40
CD69+ CD103+

C
e

ll
s,

 %

DP
Control

DP
Tapinarof

–2

2
4
6

0

8
Non T

RM

C
e

ll
s,

 %

DN
Control

DN
Tapinarof

DN, double negative; DP, double positive; IFN, interferon; IL, interleukin; SP, single positive;  T
RM

, resident memory T cell;  
TNF, tumor necrosis factor. 

T
RM

 Activation and Proliferation
■ Tapinarof treatment significantly reduced T

RM
 activation (CD107a; P=0.0024) and 

proliferation (Ki-67; P=0.0067) (Figure 6) 

Figure 6. Tapinarof Suppressed T
RM

 Activation and Proliferation in Human Skin

CD107a+

P=0.0024

Co
nt

ro
l

Ta
pi

na
ro

f
0

10

40

C
D

1
0

7
a

+
 T

 c
e

ll
s,

 %

Ta
pi

na
ro

f

Control

Individual sample/data point

Tapinarof

20

30

Ki-67+

P=0.0067

Co
nt

ro
l

0

5

25

K
i-

6
7

+
 T

 c
e

ll
s,

 %

10

15

20

 CONCLUSIONS
■ Our initial results suggest tapinarof:
  – Reduced early activation in CD4+ and CD8+ blood-derived T cells
  – Upregulated CD39 on CD4+ and CD8+ blood-derived T cells
  – Reduced the in vitro generation of CD4+ T

RM
  

  – Reduced IL-17A, IFNγ, and TNFα production by CD4+ T
RM

  
  – Reduced T cell survival in an in vitro antigen-presenting cell:T cell support assay
  –  Reduced activation and entry into the cell cycle of T

RM
 in healthy skin cultured under 

Th17-skewing conditions
■ Additional donors will be tested to confirm statistical significance
■ Future studies will also test the effect of tapinarof in vivo using NSG mice grafted with 

human skin and infused with allogeneic peripheral blood mononuclear cells (PBMCs)
■ The demonstrated effects on T

RM
 may explain the ability of tapinarof to induce a remittive 

effect in psoriasis clinical trials2 

 REFERENCES
1. Dermavant Sciences. VTAMA (tapinarof) cream, 1%: US prescribing information. 2022. https://www.vtama.com/
docs/DMVT_VTAMA_PI.pdf. Accessed December 2022. 2. Strober B, et al. J Am Acad Dermatol. 2022;87:800–
806. 3. Matos TR, et al. J Clin Invest. 2017;127.11:4031–4041. 4. Lefevre MA, et al. Curr Opin Allergy Clin Immunol. 
2021;21:355–360. 5. Zaid A, et al. Proc Natl Acad Sci U S A. 2014;111:5307–5312. 6. Larigot L, et al. Biochim Open. 
2018;7:1–9. 7. Quintana FJ, et al. Nature. 2008;453:65–71. 8. Smith SH, et al. J Invest Dermatol. 2017;137:2110–2119.

 ACKNOWLEDGMENTS
Dermavant Science, Inc. provided material for these studies under a material transfer agreement. Adult skin samples were generously provided by Drs. Simon G. Talbot, Shailesh Agarwal, and Dennis P. Orgill of the Division of Plastic Surgery 
at Brigham and Women’s Hospital, Boston, MA. Drs. Qian Zhan and Ira Kim performed immunostaining and analysis for the activation and proliferation experiment. Dr. Yoshinori Watanabe performed the antigen-presenting cell:T cell survival 
assays. K.M. and D.S.R. are employees of Dermavant Science, Inc. with stock options. R.A.C. has served as a scientific advisory board member for Science Immunology, AnaptysBio, Micreos, and SEDEC Therapeutics. Editorial support under the 
guidance of the authors was provided by ApotheCom, UK, and was funded by Dermavant Sciences, Inc. in accordance with Good Publication Practice (GPP) guidelines (Ann Intern Med. 2022;175:1298–1304). 

Contact Dr Kimberly McHale at kimberly.mchale@dermavant.com with questions or comments.