The goal of this clinical trial is to determine safety, tolerability, pharmacokinetics, preliminary efficacy, and Maximum Tolerable Dose (MTD), of intralesional FLD-103 when administered to subjects with Basal Cell Carcinoma (BCC). The main questions it aims to answer are:

• Is FLD-103 safe and well tolerated?
• What is a safe dose of FLD-103 for future studies?
• How much FLD-103 enters the bloodstream and how long does it take to be cleared from the body?
• Does FLD-103 reduce the size of the tumor?

Participants will:

• Receive either a Single Ascending Dose (SAD) of FLD-103 or Multiple Ascending Doses (MAD) of FLD-103 once weekly for four (4) weeks.
• Visit the clinic a day after receiving a dose and once weekly for four (4) weeks after that for checkups and tests.

Inclusion Criteria:

• You are between 18 and 85 years old.
• You are willing to attend all study visits and follow the study procedures.
• You have been diagnosed with at least one nodular basal cell carcinoma (a type of skin cancer) that has never been treated and suitable for treatment and final excision by the Investigator.
• You are willing to avoid certain medications during the study as instructed by the study doctor.
• You are not currently participating in another clinical study.
• If you are a woman who could become pregnant, you must:
• Have a negative pregnancy test at the start of the study.
• Use effective birth control during the study and for 90 days after your last dose.
• Not breastfeed during the study and for 90 days after your last dose.
• If you are a man, you must use a condom during the study and for 90 days after your last dose if you have sex with a partner who could become pregnant.

Exclusion Criteria:

• You are currently breastfeeding.
• You have a known allergy or sensitivity to any ingredient in the study drug or to red tattoo ink.
• Your skin lesion is located in a high-risk area, such as near the eyes, nose, ears, lips, scalp, or on the hands or fingers.
• Your skin lesion needs to be removed urgently.
• Your basal cell carcinoma has spread to other parts of the body.
• You have received radiation therapy directly on or near the skin lesion being treated in this study.
• You have received phototherapy (such as Ultraviolet A or B light therapy) in the past 4 weeks or are expected to receive it during the study.
• You have been diagnosed with a liver or kidney disease that the study doctor considers significant.
• You are immunocompromised or have an active infection such as Human Immunodeficiency Virus (HIV), Hepatitis B, Hepatitis C or active Tuberculosis.
• You have or had another cancer in the past 5 years
• You have a skin condition associated with an increased risk of developing skin cancers (such as Xeroderma Pigmentosum).
• You have uncontrolled high blood pressure or a heart rhythm problem.
• You have had significant alcohol or drug use issues in the past 6 months, or have a mental health condition that the study doctor believes may affect your ability to participate safely.
• You are currently taking certain medications that are not allowed during the study
• You are an employee or family member of an employee at the study site or of the study doctor.