Eligibility Criteria:
A. At least 10% total BSA with some scalp involvement (15 evaluable subjects ages 7 to 11 years) or B. At least 3% total BSA with some scalp involvement (10 evaluable subjects ages 2 to 6 years). "Napkin" psoriasis (ie, psoriasis in the diaper area) can be included in the BSA calculation for this age group.
Key Inclusion Criteria:
* Male or female subjects, ages 2 to 11 years, inclusive, at the time of consent
* For the maximum-use cohort:
A. ISGA of 3 or higher at Screening (see Appendix 2). Ages 7 to 11 - at least 10% total BSA with some scalp involvement (See Appendix 1).
Ages 2 to 6 - at least 3% total BSA (napkin psoriasis included) with some scalp involvement (See Appendix 1).
-For the general use cohort, an ISGA score of 2 or 3 at Screening with no BSA minimum.
Key Exclusion Criteria:
* Any inflammatory skin disease in the treatment area that may confound the evaluation of the plaque psoriasis
* Current diagnosis of unstable forms of psoriasis in the treatment area, including guttate, erythrodermic, exfoliative, or pustular psoriasis
* Use of any topical treatments that have a known beneficial effect on psoriasis, including but not limited to corticosteroids, retinoids, vitamin D derivatives, coal tar, tazarotene, medicated shampoos, or anthralin, within 2 weeks prior to enrollment
* Use of nonbiologic systemic antipsoriatic therapy (eg, corticosteroids, psoralen, retinoids, methotrexate, cyclosporine, other immunosuppressive agents), biologic therapy (eg, adalimumab, etanercept, golimumab, infliximab, ustekinumab), or phototherapy (eg, psoralen and ultraviolet A \[PUVA\], ultraviolet B \[UVB\]) within 4 weeks prior to enrollment
* Use of or need for initiation of any nonpsoriatic therapy that might affect psoriasis (including antimalarials, β-blockers, interferon, or lithium) within 4 weeks prior to enrollment
* Use of medications that affect or change calcium and parathyroid hormone (PTH) concentrations or interfere with the measurement of calcium or PTH concentrations within 4 weeks prior to enrollment
* Known difficult venous access beyond that expected for subject age
* Average daily ingestion of more than 2000 mg of elemental calcium or more than 1000 IU of vitamin D within 2 weeks prior to enrollment
* History of hypersensitivity, known allergy, or other adverse reaction to calcipotriene or other vitamin D analogs or to any component of the study product
* Current or past history of hypercalcemia, vitamin D toxicity, severe renal insufficiency, or severe hepatic disorders
* Use of any investigational therapy within 4 weeks prior to enrollment
* Pregnant or breast feeding female or females who do not use contraception
* Current immunosuppression
* Albumin-adjusted serum calcium at screening that is above the upper limit of normal