Clinical Pharmacology for Zoryve Foam
Mechanism Of Action
Roflumilast and its active metabolite (roflumilast N-oxide) are inhibitors of PDE4. Roflumilast and roflumilast N-oxide inhibition of PDE4 (a major cyclic 3',5'-adenosine monophosphate (cyclic AMP) metabolizing enzyme) activity leads to accumulation of intracellular cyclic AMP. The specific mechanism(s) by which roflumilast exerts its therapeutic action is not well defined.
Pharmacodynamics
Pharmacodynamics of ZORYVE foam, 0.3%, in the treatment of seborrheic dermatitis and plaque psoriasis is unknown.
Pharmacokinetics
Absorption
Seborrheic Dermatitis
The pharmacokinetics of ZORYVE foam, 0.3%, was investigated in 10 adult and 10 pediatric (11 to 16 years of age) subjects with seborrheic dermatitis. In this study, a mean dose of approximately 4.1 g of ZORYVE foam, 0.3%, was applied once daily for 15 days to a mean ± SD body surface area (BSA) involvement of 6.5 ± 1.08% and 5.5 ± 1.27% in adult and pediatric subjects, respectively. Plasma concentrations of roflumilast were quantifiable in all but two subjects at Day 15. Plasma concentrations of roflumilast N-oxide were quantifiable in all subjects at Day 15. Following application of ZORYVE foam, 0.3%, the plasma concentration versus time profile was relatively flat, with mean peak-to-trough ratios of 1.68 and 1.62 for roflumilast and roflumilast N-oxide, respectively.
In adults, the mean ± SD maximum concentration (Cmax) was 2.2 ± 1.6 and 13.8 ± 9.0 ng/mL for roflumilast and the N-oxide metabolite, respectively. The mean ± SD systemic exposure (AUC0-24) was 36.6 ± 23.7 and 261 ± 190 h•ng/mL for roflumilast and the N-oxide metabolite, respectively. In pediatric subjects, the extrapolated mean ± SD AUC0-24 (based on pre-dose concentration) was 25.1 ± 30.2 and 253 ± 404 h•ng/mL for roflumilast and the N-oxide metabolite, respectively.
Plaque Psoriasis
The pharmacokinetics of ZORYVE foam, 0.3%, was investigated in 19 adults and 7 pediatric subjects 12 to 16 years of age with plaque psoriasis of the scalp and body. The entire scalp (BSA of approximately 4.5%) was treated in addition to the mean ± SD BSA involvement on the body of 25.0 ± 7.88% and 10.4 ± 0.54% in adults and pediatric subjects, respectively. In this study, the mean daily dose administered in adults was 10.3 g and in pediatric subjects from 12 to 16 years of age was 5.3 g of ZORYVE foam, 0.3%, once daily for 15 days. Following application of ZORYVE foam, 0.3%, the plasma concentration versus time profile was flat, with mean peak-to-trough ratios of approximately 1.2 for both roflumilast and roflumilast N-oxide.
In adults, the mean ± SD Cmax was 4.48 ± 2.28 and 29.9 ± 17.5 ng/mL for roflumilast and the N-oxide metabolite, respectively, on Day 15. The mean ± SD AUC0-24 was 90 ± 58.7 and 567 ± 436 h•ng/mL for roflumilast and the N-oxide metabolite, respectively, on Day 15. In pediatric subjects, the extrapolated mean ± SD AUC0-24 (based on pre-dose concentration) was 35.5 ± 41.4 and 270 ± 293 h•ng/mL for roflumilast and the N-oxide metabolite, respectively, on Day 15.
Distribution
Plasma protein binding of roflumilast and its N-oxide metabolite is approximately 99% and 97%, respectively.
Elimination
The plasma clearance after short-term intravenous infusion of roflumilast is on average about 9.6 L/h. Following topical administration, the mean half-lives of both roflumilast and the N-oxide metabolite were in the range of 3.6 to 5 days.
Metabolism
Roflumilast is extensively metabolized via Phase I (cytochrome P450) and Phase II (conjugation) reactions. The N-oxide metabolite is the only major metabolite observed in the plasma of humans. Following oral administration, roflumilast and roflumilast N-oxide account for the majority (87.5%) of total dose administered in plasma. Roflumilast was not detectable in urine, while roflumilast N-oxide was only a trace metabolite (less than 1%). Other conjugated metabolites such as roflumilast N-oxide glucuronide and 4-amino-3,5-dichloropyridine N-oxide were detected in urine.
While roflumilast is 3 times more potent than roflumilast N-oxide at inhibition of the PDE4 enzyme in vitro, the plasma AUC of roflumilast N-oxide on average is approximately 7-fold greater than the plasma AUC of roflumilast following topical administration. A similar ratio was observed following intravenous administration, whereas following oral administration the N-oxide metabolite circulated on average about 10-fold higher than the parent drug.
Specific Populations
Following topical administration, no clinically significant differences in the pharmacokinetics of roflumilast and roflumilast N-oxide were observed based on age, sex, race, or ethnicity.
Patients With Hepatic Impairment
No studies were conducted with topical roflumilast in subjects with hepatic impairment; however, oral roflumilast 250 mcg once daily for 14 days was studied in subjects with mild to moderate hepatic impairment classified as Child-Pugh A and B (8 subjects in each group). The AUC of roflumilast and roflumilast N-oxide were increased by 51% and 24%, respectively, in Child-Pugh A subjects and by 92% and 41%, respectively, in Child-Pugh B subjects, as compared to age-, weight-, and gender-matched healthy subjects. The Cmax of roflumilast and roflumilast N-oxide were increased by 3% and 26%, respectively, in Child-Pugh A subjects and by 26% and 40%, respectively, in Child-Pugh B subjects, as compared to healthy subjects [see CONTRAINDICATIONS].
Patients With Renal Impairment
No studies were conducted with topical roflumilast in subjects with renal impairment. Following oral administration in 12 subjects with severe renal impairment, no clinically significant differences in the pharmacokinetics of roflumilast and roflumilast N-oxide were observed.
Drug Interaction Studies
Clinical Studies
No formal drug-drug interaction studies were conducted with roflumilast topical foam, 0.3%.
Since a major step in roflumilast metabolism is the N-oxidation of roflumilast to roflumilast N-oxide by CYP3A4 and CYP1A2, drug interaction studies were performed with oral roflumilast and systemic inhibitors of CYP3A4 and CYP1A2 [see DRUG INTERACTIONS].
Erythromycin
In an open-label crossover study in 16 healthy volunteers, the co-administration of CYP3A4 inhibitor erythromycin (500 mg 3 times daily for 13 days) with a single oral dose of 500 mcg roflumilast resulted in 40% and 70% increase in Cmax and AUC for roflumilast, respectively, and a 34% decrease and a 4% increase in Cmax and AUC for roflumilast N-oxide, respectively.
Ketoconazole
In an open-label crossover study in 16 healthy volunteers, the co-administration of a strong CYP3A4 inhibitor ketoconazole (200 mg twice daily for 13 days) with a single oral dose of 500 mcg roflumilast resulted in 23% and 99% increase in Cmax and AUC for roflumilast, respectively, and a 38% reduction and 3% increase in Cmax and AUC for roflumilast N-oxide, respectively.
Fluvoxamine
In an open-label crossover study in 16 healthy volunteers, the co-administration of dual CYP 3A4/1A2 inhibitor fluvoxamine (50 mg daily for 14 days) with a single oral dose of 500 mcg roflumilast showed a 12% and 156% increase in roflumilast Cmax and AUC along with a 210% decrease and 52% increase in roflumilast N-oxide Cmax and AUC, respectively.
Enoxacin
In an open-label crossover study in 16 healthy volunteers, the co-administration of dual CYP 3A4/1A2 inhibitor enoxacin (400 mg twice daily for 12 days) with a single oral dose of 500 mcg roflumilast resulted in an increased Cmax and AUC of roflumilast by 20% and 56%, respectively. Roflumilast N-oxide Cmax was decreased by 14% while roflumilast N-oxide AUC was increased by 23%.
Cimetidine
In an open-label crossover study in 16 healthy volunteers, the co-administration of a dual CYP 3A4/1A2 inhibitor cimetidine (400 mg twice daily for 7 days) with a single oral dose of 500 mcg roflumilast resulted in a 46% and 85% increase in roflumilast Cmax and AUC; and a 4% decrease in Cmax and 27% increase in AUC for roflumilast N-oxide, respectively.
Oral Contraceptives Containing Gestodene And Ethinyl Estradiol
In an open-label crossover study in 20 healthy adult volunteers, co-administration of a single oral dose of roflumilast with repeated doses of a fixed combination oral contraceptive containing 0.075 mg gestodene and 0.03 mg ethinyl estradiol to steady state caused a 38% increase and 12% decrease in Cmax of roflumilast and roflumilast N-oxide, respectively. Roflumilast and roflumilast N-oxide AUCs were increased by 51% and 14%, respectively.
In Vitro Studies
Cytochrome P450 (CYP) Enzymes: In vitro studies suggest that the biotransformation of roflumilast to its N-oxide metabolite is mediated by CYP1A2 and 3A4. Based on further in vitro results in human liver microsomes, roflumilast and roflumilast N-oxide therapeutic plasma concentrations do not inhibit CYP1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1, 3A4/5, or 4A9/11; therefore, there is a low probability of relevant interactions with substances metabolized by these P450 enzymes. In addition, in vitro studies demonstrated no induction of the CYP1A2, 2A6, 2C9, 2C19, or 3A4/5 and only a weak induction of CYP2B6 by roflumilast.
Clinical Studies
Seborrheic Dermatitis
Two randomized, double-blind, vehicle-controlled trials (STRATUM [NCT04973228] and Trial 203 [NCT04091646]) enrolled a total of 683 adult and pediatric subjects with seborrheic dermatitis involving the scalp, face, and/or body with an Investigator Global Assessment (IGA) of moderate or severe (IGA of 3 or 4 on a 5-point scale from 0 to 4). In each trial, subjects were randomized 2:1 to receive ZORYVE foam, 0.3%, or vehicle foam applied once daily for 8 weeks. The combined trial population was 50% male, 79% White, 11% Black, 5% Asian, and 5% other races; for ethnicity, 79% identified as non-Hispanic/Latino and 21% identified as Hispanic/Latino. In Trial STRATUM, the trial population ranged in age from 9 to 87 years, including 7% of subjects who were 9 to 17 years of age and 12% of subjects who were 65 years of age or older. At baseline, 94% of subjects had an IGA score of 3 (moderate), and 6% had an IGA score of 4 (severe). At baseline, 67% of subjects had a Worst Itch-Numeric Rating Scale (WI-NRS) score of 4 or higher on a scale of 0 to 10. In Trial 203, the trial population ranged in age from 18 to 85 years, including 18% who were 65 years of age or older. At baseline, 93% of subjects had an IGA score of 3 Â (moderate), and 7% had an IGA score of 4 (severe). At baseline, 81% of subjects had a Worst Itch-Numeric Rating Scale (WI-NRS) score of 4 or higher on a scale of 0 to 10.
The primary endpoint was the proportion of subjects who achieved IGA treatment success at Week 8 (Table 3). Success was defined as a score of “Clear” (0) or “Almost Clear” (1), plus a 2-grade improvement from baseline.
Table 3: IGA Treatment Success at Week 8 in Adult and Pediatric Subjects 9 Years of Age and Older with Moderate to Severe Seborrheic Dermatitis in Trial STRATUM and Trial 203
|
STRATUM |
Trial 203 |
| ZORYVE foam, 0.3% |
Vehicle foam |
ZORYVE foam, 0.3% |
Vehicle foam |
| Number of subjects randomized |
N=304 |
N=153 |
N=154 |
N=72 |
| IGA success* |
79.5% |
58.0% |
73.1% |
40.8% |
| Difference from Vehicle (95% CI)† |
20.6%
(11.2%, 30.0%) |
33.8%
(20.3%, 47.4%) |
Abbreviations: CI = Confidence Interval
*IGA treatment success was defined as an IGA score of “Clear” (0) or “Almost Clear” (1), plus a 2-grade IGA score improvement from baseline at Week 8 (Multiple Imputation).
†Treatment difference and 95% CI are based on the CMH method stratified by pooled site and baseline IGA strata. |
In Trial STRATUM, among subjects with a baseline WI-NRS score of at least 4 (67% of subjects), there was a higher percentage of subjects who achieved a reduction of at least 4 points from baseline at Week 8 in the group who received ZORYVE foam, 0.3%, compared to the group who received vehicle foam (62.8% vs. 40.6% for a treatment difference of 25.7% and 95% CI of (13.4, 38.1)).
Plaque Psoriasis
Two randomized, double-blind, vehicle-controlled trials (ARRECTOR [NCT05028582] and Trial 204 [NCT04128007]) enrolled a total of 736 adult and pediatric subjects 12 years of age and older with mild to severe plaque psoriasis of the scalp and body. In each trial, subjects were randomized 2:1 to receive ZORYVE foam, 0.3%, or vehicle foam applied once daily for 8 weeks. The combined trial population was 55% female, 85% White, 5% Black, 6% Asian, and 4% other races; for ethnicity, 79% identified as non-Hispanic/Latino and 19% identified as Hispanic/Latino. The median age was 47 years (range 12 to 87 years).
In Trial ARRECTOR, the trial population ranged in age from 12 to 87 years, including 2% of subjects who were 12 to 17 years of age and 13% of subjects who were 65 years of age or older. At baseline, 86% of subjects had a Scalp Investigator Global Assessment (S-IGA) score of 3 (moderate) on a 5-point scale of 0 to 4, and 14% had an S-IGA score of 4 (severe); 28% of subjects had a Body Investigator Global Assessment (B-IGA) score of 2 (mild), 67% of subjects had a B-IGA score of 3 (moderate), and 5% had a B-IGA score of 4 (severe). At baseline, 76% of subjects had a Scalp Itch-Numeric Rating Scale (SI-NRS) score of 4 or higher on a scale of 0 to 10 and 73% had a Worst Itch-Numeric Rating Scale (WI-NRS) score of 4 or higher.
In Trial 204, the trial population ranged in age from 12 to 87 years, including 1% of subjects who were 12 to 17 years of age, and 9% who were 65 years of age or older. At baseline, 11% of subjects had an S-IGA score of 2 (mild), 76% of subjects had an S-IGA score of 3 (moderate), and 13% had an S-IGA score of 4 (severe); 36% of subjects had a B-IGA score of 2 (mild), 59% of subjects had a B-IGA score of 3 (moderate), and 5% had a B-IGA score of 4 (severe). At baseline, 89% of subjects had an SI-NRS score of 4 or higher on a scale of 0 to 10.
In both trials, S-IGA treatment success, a primary endpoint in ARRECTOR and Trial 204, and B-IGA treatment success, a primary endpoint in ARRECTOR, were defined as a score of “Clear” (0) or “Almost Clear” (1), plus a 2-grade improvement from baseline.
Table 4: S-IGA and B-IGA Treatment Success at Week 8 in Adult and Pediatric Subjects 12 Years of Age and Older with Plaque Psoriasis of the Scalp and Body in Trial ARRECTOR and Trial 204
|
Trial ARRECTOR |
Trial 204 |
| ZORYVE foam, 0.3% |
Vehicle foam |
ZORYVE foam, 0.3% |
Vehicle foam |
| Number of subjects randomized |
N=281 |
N=151 |
N=200 |
N=104 |
| S-IGA success* |
66.4% |
27.8% |
56.7% |
11.0% |
| Difference from Vehicle (95% CI)† |
37.1%
(27.1%, 47.1%) |
47.7%
(37.9%, 57.5%) |
| B-IGA success* |
45.5% |
20.1% |
39.0% |
7.4% |
| Difference from Vehicle (95% CI)† |
24.8%
(15.0%, 34.6%) |
32.4%
(23.3%, 41.6%) |
Abbreviations: CI = Confidence Interval
*S-IGA treatment success and B-IGA treatment success were defined as a score of “Clear” (0) or “Almost Clear” (1), plus a 2-grade score improvement from baseline at Week 8 (Multiple Imputation).
†Treatment difference and 95% CI are based on the CMH method stratified by pooled site and baseline IGA strata. |
SI-NRS success and WI-NRS success were defined as a reduction of at least 4 points from baseline with a baseline score of at least 4. In Trial ARRECTOR, among subjects with a baseline SI-NRS score of at least 4 (75% of subjects), a higher percentage of subjects achieved SI-NRS success at Week 8 in the group who received ZORYVE foam, 0.3%, compared to the group who received vehicle foam (65.3% vs. 30.3% for a treatment difference of 35.4% and 95% CI of (23.9, 47.0)). In Trial ARRECTOR, among subjects with a baseline WI-NRS score of at least 4 (72% of subjects), a higher percentage of subjects achieved WI-NRS success at Week 8 in the group who received ZORYVE foam, 0.3%, compared to the group who received vehicle foam (63.1% vs. 30.1% for a treatment difference of 32.8% and 95% CI of (20.3, 45.2)).