Figure legends
Figure 1 CONSORT flow
diagram of clinical trial . For PK and population PK analysis subjects
in which any spillage occurred during injection were excluded. Other
analyses were done with all subjects who completed the study (N=24).
Figure 2 Volunteer reported outcomes indicate preference for
s.c. administration versus i.d. administration. Healthy volunteers were
injected with a single dose of adalimumab in the upper thigh and placebo
in the contralateral upper thigh administered i.d. using a hollow
microneedle or s.c. using a conventional needle. Pain scores were
measured during insertion of the needle (insertion pain) and during
infusion of the compound (injection pain) using a 100 points VAS.
Insertion and injection pain were normalized to the pain score during a
Mantoux which the volunteers received during screening. (A) VAS pain
scores for insertion pain. No differences were observed between s.c. and
i.d. insertion pain (p=0.68). (B) VAS pain scores for injection and
post-injection pain. Injection pain was significantly
(p<0.0001) higher for i.d. compared to s.c. injection.
Post-injection pain was not present. After injection, subjects were
asked multiple choice questions about their preference, for (C) how they
experienced the injection, (D) how they would like to get a hypothetical
future injection, (E) and for which injection they had fear. (A-E): N=12
per group, except for Mantoux where n=24. (A-B): mean ± SD; repeated
measures ANOVA; **** p<0.0001. NA:
not available because not measured. VAS: visual analogue scale.
Figure 3 Pharmacokinetics of adalimumab and anti-adalimumab
antibodies after i.d. or s.c. Injection . Mean anti-adalimumab levels
after (A) s.c. and (B) i.d. administration (n=12 per administration
type). (C) Average anti-adalimumab levels for subjects with
anti-adalimumab antibodies (n=10 for s.c. administration and n=6 for
i.d. administration). (D) Serum adalimumab concentrations over time (D,
n=10 for s.c. administration and n=9 for i.d. administration,
non-compartmental analysis). (C-D) Mean ± SD. (E) Schematic depiction of
population PK model. (F) Adalimumab absorption kinetics over time after
adalimumab administration following microneedle (i.d.) or s.c.
administration (typical population PK model). F: bioavailability; ID:
intradermal; ka: absorption rate constant; SC:
subcutaneous.
Figure 4 Similar cytokine
production after i.d. or s.c. adalimumab administration (A) TNFα, (B)
IL-1β, (C) IL-8, (D) IFNγ, and (E) IL-6 release after ex vivostimulation with LPS/aluminium hydroxide of whole blood samples. No
gender effect was observed. Mean ± SD. A-E: N=12 per group, repeated
measures ANOVA.
Figure 5 Characterization
of skin reaction following i.d. and s.c. injection. (A-C) 3D
photography; (A) Typical bleb after i.d. injection. (B) Maximum height
and volume of injection site. Volume was determined by outlining bleb
circumference and height and calculated using the DermaPix
(QuantifiCare, USA) algorithm for volume (σ = 5). Bleb height and volume
did not differ between i.d. adalimumab and i.d. placebo (height p=0.26,
volume p=0.29). (D) Redness of the injection sites, determined using a
multispectral camera, displayed using the CIELAB *a ratio (green colours
are negative, red colours positive). The more positive the CIELAB *a
ratio, the redder the injection site. I.d. adalimumab and placebo
injections induced significantly more redness of the skin compared to
s.c. adalimumab and placebo injections (p<0.0001). Within i.d.
administration, skin redness induced by adalimumab injection was
significantly higher than for placebo injection (p=0.0014) (E-F)
Representative OCT images of i.d. injection 10 minutes post injection;
(D-E) Cross-sectional planes of i.d. injection, and (F) top view of skin
surface with three puncture holes. (G) LSCI was used to quantify skin
perfusion in arbitrary PU 10 minutes post-injection. (H) Injection site
surface area 10 minutes post injection. Area was calculated based on
values above an arbitrary threshold of 90 PU. A significant difference
in skin perfusion and surface area 10 minutes post injection was
observed for both administration method (p<0.0001) and
treatment (p<0.0001). (I) Representative LSCI images of both
injection methods and treatments 10 minutes post injection. LSCI: laser
speckle contrast imaging; OCT: optical coherence tomography; PU:
perfusion units; B, D, G, H: mean ± SD, N=12 per group, repeated
measures ANOVA, **** p<0.0001.