The study fully enrolled and completed after last patient completed the study

The purpose of this first in human and proof of concept study is to characterize the safety, tolerability and initial efficacy of CLL442 in patients with Squamous Cell Carcinoma in situ (SCCis) to enable further clinical development of CLL442.

Inclusion Criteria:

1. Written informed consent has been obtained.
2. Male and female patients, age ≥ 18 to ≤ 90 years (at the time of the screening visit).
3. A primary, clinically diagnosed and histologically confirmed cutaneous SCC in situ lesion, with or without the involvement of the follicular unit, and histologically diagnosed within 30 days of the screening visit. The post-biopsy residual SCCis lesion must be visually evident and at least 3 mm in either length or width.
4. The lesion must be located in a place easily accessible for topical application by the patient or their caregiver, excluding the genitals, perianal area, sub-ungual area, eyelids, ear and must be >1 cm away from the eyes and mouth.

Exclusion Criteria:

1. Evidence of dermatological disease or histological evidence of a confounding skin condition in the treatment area, including but not limited to BCC, worse level/grade of SCC, rosacea, psoriasis, atopic dermatitis, eczema, xeroderma pigmentosa, verrucous lesions or any other tumor in the biopsy specimen. Lesions with atypical histology such as: spindle cell SCC, acantholytic SCC, clear cell SCC, adenosquamous SCC, desmoplastic SCC or lesions that have been present for a short time and have been fast growing.
2. Treatment of the target SCCis lesion within 8 weeks of screening visit by any of the following treatments: Liquid nitrogen, Photochemotherapy (PUVA), Long wave ultra violet radiation (UVB light), surgical excision or curettage within 1 cm of target lesion.; Systemic retinoids.; Ionizing radiation or interlesional injections or; Undergone a facial resurfacing procedure, i.e., chemical peel, laser resurfacing, dermabrasion, within the target lesion;
3. Treatment with the following topical agents within the 4 weeks prior to the screening visit: Levulanic acid, 5-fluorouracil, corticosteroids, retinoids, diclofenac, hyaluronic acid, imiquimod.
4. History of recurrence of the target SCCis lesion.
5. Systemic use of immunosuppressive drugs within 4 weeks prior to screening visit or during the treatment period - Photodynamic therapy or immunomodulators, cytotoxic drugs, or interferon/interferon inducers within 4 weeks prior to study entry or expected during the study.
6. Women of child-bearing potential, unless they are using at least basic methods of contraception during dosing of investigational drug.
7. Pregnant or nursing (lactating) women.

Novartis is committed to sharing access to patient-level data and supporting clinical documents from eligible studies with qualified external researchers. Requests are reviewed and approved by an independent review panel on the basis of scientific merit. All data provided is anonymized to protect the privacy of patients who have participated in the trial in line with applicable laws and regulations.

This trial data availability is according to the criteria and process described on www.clinicalstudydatarequest.com

investigator and patient blinded