Testing the Efficacy of Topical Calcipotriene Plus 5-Fluorouracil Combination to Activate the Immune System Against Precancerous Skin Lesions in Organ Transplant Recipients

PRIMARY OBJECTIVE: I. To determine the induction of CD4+ TRM cells (CD3+CD4+CD103+) in the actinic keratosis at one day after completing one and two courses of calcipotriene plus 5-fluorouracil (5-FU) immunotherapy compared with before treatment. SECONDARY OBJECTIVES: I. To evaluate the persistence of CD4+ TRM (CD3+CD4+CD103+) in the AK at 6 months after initiation of treatment compared with before treatment. II. To evaluate the persistence of CD4+ TRM (CD3+CD4+CD103+) in the AK at 6 months after initiation of treatment compared with after completing one and two courses of treatment. III. To determine the percent reduction in the number of AKs on the treated areas at 8 weeks after one and two courses of calcipotriene plus 5-FU immunotherapy compared with before treatment. IV. To determine the erythema extent and intensity scores of the treated anatomical sites at one day after the completion of one and two courses of calcipotriene plus 5-FU immunotherapy. V. To determine differences in AK clearance between the treated anatomical sites (upper extremities versus \[vs.\] face vs. scalp). VI. To assess the safety and tolerability of one and two courses of calcipotriene plus 5-FU treatment. VII. To assess any incidence of biopsy-proven acute organ rejection of the graft. EXPLORATORY OBJECTIVES: I. To determine the percentage of participants with a new diagnosis of squamous cell carcinoma (SCC) on the treated anatomical sites at 6 months after the initiation of treatment compared with the identical duration prior to therapy. II. To evaluate the persistence of CD4+ TRM (CD3+CD4+CD103+) in the AK at 8 weeks after treatment with one and two courses of calcipotriene plus 5-FU compared with before treatment. III. To evaluate the induction of TSLP, CD8+ TRM and natural killer (NK) cell infiltrates in the AK at one day after one and two courses of calcipotriene plus 5-FU immunotherapy compared with before treatment. IV. To evaluate the induction of other immune cells/factors in the AK at one day after one and two courses of calcipotriene plus 5-FU immunotherapy compared with before treatment. V. To determine the induction of TSLP, CD3+ T, CD4+ T, CD8+ TRM, NK cell and other immune cells/factors in the AK at one day after two courses compared with one day after one course of calcipotriene plus 5-FU immunotherapy. VI. To evaluate the persistence of CD8+ TRM, NK cells in the AK at 8 weeks after treatment with one and two courses of calcipotriene plus 5-FU compared with before treatment. VII. To evaluate the persistence of CD8+ TRM, NK cells in the AK at 6 months after initiation of treatment compared with before treatment. VIII. To compare the immune infiltrate in any SCC that develops over 6 months after one and two courses calcipotriene plus 5-FU immunotherapy with SCCs that developed before treatment using archived tumor samples. IX. To evaluate the effect of number and type of field therapy and the number of cryotherapies after the trial, age, gender, history of immunosuppressive therapy, exposure to ionizing radiation or chemical carcinogens before and after transplantation, genetic factors (Fitzpatrick skin type I, II and III), pre-transplantation end-organ disease on SCC outcomes in OTRs. X. To compare the immune induction outcomes in AKs versus the normal skin samples. OUTLINE: Participants receive calcipotriene plus 5-fluorouracil cream topically twice a day (BID) for 6 consecutive days on study. Participants also undergo skin biopsies throughout the study. Patients who continue to experience AKs at week 8 may receive a second course of calcipotriene plus 5-fluorouracil cream topically BID for 6 consecutive days on study.