A Phase 1 interventional study of Combination field therapy with 5-fluorouracil and calcipotriene (5FU/C) in Actinic Keratoses, sponsored by Cedars-Sinai Medical Center. Not yet recruiting at 2 sites in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-05.
Sponsored by Cedars-Sinai Medical Center · Phase 1, Interventional, and Treatment
Combination field therapy with 5-fluorouracil and calcipotriene (5FU/C) has become standard of care among dermatologists for the field treatment of diffuse actinic keratoses (AKs). Data suggest that the addition of calcipotriene elicits a sustained T cell memory allowing for both short and long-term AK clearance. Our objective is to evaluate the efficacy, as well as, document the timing, severity and duration of local cutaneous reactions to topical treatment with 5FU/C for the treatment of AKs.
The primary objectives of this study is to determine whether chronic, systemic immunosuppression alters the short and long-term clinical 9 efficacy of 5FU/C, presumably through decreased CD4+ T cell-mediated immune response in the skin.
Our central hypothesis is that SOTRs (Solid Organ Transplant Recipients) exhibit attenuated immunologic activation in response to 5FU/C, resulting in reduced AK clearance and potentially requiring extended duration of treatment compared to their immunocompetent counterparts. To test our hypothesis, we propose the following aims:
Aim 1. To assess the clinical efficacy of 5FU/C to treat AKs.
Our primary endpoint is the percent change from baseline in total AKs at week 9. Secondary endpoints include complete (100%) and partial (75%) clearance of AKs at week 9. These endpoints mirror prior pivotal trials of 5FU/C and will directly evaluate whether immunosuppression reduces clinical efficacy of 5FU/C to treat AKs.1,2
Aim 2. To determine whether extending 5FU/C therapy from 4 days to 8 days improves AK clearance in immunosuppressed patients.
We wish to provide an evidence-based rationale for extended treatment courses among immunosuppressed patients. Prior studies suggest immunosuppressed patients experience reduced local inflammatory responses and lower clearance rates when using topical field treatments for AKs, and clinical practice often involves empirically extending therapy in these instances. No prospective trial, however, has evaluated whether extending treatment duration improves outcomes. Our study's internal comparison of an extended exposure to 5FU/C in SOTRs will optimize treatment parameters and will provide the first evidence-based guidance on treatment duration for field cancerization in SOTRs.
Aim 3. To determine whether systemic immunosuppression affects local immune function in the skin.
Topical chemotherapeutics and immunomodulating agents (e.g. 5FU/C) elicit local reactions including erythema, scaling, edema, erosions, and pain.1-4 These local cutaneous reactions often serve as markers of a patient's immune activation and predict expected treatment success following cessation of therapy. Given that 5FU/C relies on the host's immune system to mount a T cell-mediated immune response, we anticipate decreased immune activation (and, therefore, decreased local, cutaneous reactions) among immunosuppressed, compared to immunocompetent, patients following the standard 4-day treatment course. We aim to evaluate local cutaneous reactions among SOTRs following an extended 8-day treatment to determine whether immunosuppressed patients require longer duration of therapy to generate immune responses comparable to immunocompetent patients following the standard 4-day treatment.
Completion of this study will fill a major evidence gap by establishing how immunosuppression influences the efficacy of a widely used field of therapy in dermatology. The findings will directly inform clinical practice guidelines, optimize treatment duration for immunosuppressed patients, and reduce reliance on empiric decision-making. Given the expanding population of transplant recipients, nationally and at Cedars-Sinai, and their disproportionate NMSC burden, the proposed research addresses an urgent public health need and aligns directly with CS Cancer Center's focus on cancer prevention.
343 studies on the registry are indexed under Keratosis, Actinic; 29 are open to participants now.
This study's planned enrollment of 96 is above the median of 60 across 295 interventional studies indexed under Keratosis, Actinic.
Browse Keratosis, Actinic studies →Cedars-Sinai Medical Center is the lead sponsor of 456 studies on the registry; 107 are open to participants now.
Of its 65 completed or terminated interventional studies of FDA-regulated products, 49 (75%) have results posted.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
All patients (n=32 immunocompetent patients and n=64 immunosuppressed, SOTRs) will receive 30g of 5FU/C, compounded by Strive Pharmacy (a FDA-registered 503B outsourcing facility). Solid Organ Transplant Recipients subjects will receive either 4 or 8-days of topical 5FU/C. Duration of treatment with 5FU/C ranges from 4 to 14-days in the clinical dermatology setting, depending on provider experience and judgement, patient compliance, anatomic location, and thickness of AKs.5 Roughly half (n=32) of the SOTRs will receive 4-days of 5FU/C and half (n=32) will receive 8-days of 5FU/C. This study design represents real-world clinical practice.
To assess the clinical efficacy of 5FU/C to treat Actinic Keratoses
Our primary endpoint is the percent change from baseline in total AKs at week 9. Secondary endpoints include complete (100%) and partial (75%) clearance of AKs at week 9. These endpoints mirror prior pivotal trials of 5FU/C and will directly evaluate whether immunosuppression reduces clinical efficacy of 5FU/C to treat AKs.
Time frame: 9 Weeks
Plan to share: Undecided
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