Tirbanibulin 1% Ointment for the Treatment of Actinic Keratosis on the Back of the Hands

Inclusion Criteria:

* o Informed consent

  * Diagnosed with AK on both hands
  * 4-8 AK lesions on each hand, difference in number of lesions \< 20%
  * Grade of lesions comparable in both hands: non hypertrophic, non-hyperkeratotic
  * Willing and able to comply with all study procedures
  * Use of medically acceptable contraception (both sexes)
  * 18 - 99 years of age.

Exclusion Criteria:

* o History of sensitivity and/or allergy to any of the ingredients in the study medication.

  * Open lesions of any kind on the hands
  * Concomitant cutaneous malignancy in treatment area
  * Immune deficiency
  * Participation in another clinical trial during the last 6 months
  * Had been previously treated with Tirbanibulin
  * Anticipated need for in-patient hospitalisation or in-patient surgery from Day 1 to Day 57.
  * Treatment with 5-fluorouracil (5-FU), imiquimod, diclofenac, photodynamic therapy, or other treatments for AK within the treatment area or within 2 cm of the treatment area within 8 weeks prior to the Screening Visit.
  * Use of the following therapies and/or medications within 2 weeks prior to the Screening Visit:

    * Cosmetic or therapeutic procedures (eg, use of liquid nitro-gen, surgical excision, curettage, dermabrasion, medium or greater depth chemical peel, laser resurfacing) within the treatment area or within 2 cm of the selected treat-ment area
    * Acid-containing therapeutic products (eg, salicylic acid or fruit acids, such as alpha and beta-hydroxyl acids and gly-colic acids), topical retinoids, or light chemical peels within the treatment area or within 2 cm of the selected treat-ment area
    * Topical salves (nonmedicated/nonirritant lotion and cream were acceptable) or topical steroids within the treatment area or within 2 cm of the selected treatment area; artifi-cial tanners within the treatment area or within 5 cm of the selected treatment area.
  * Use of the following therapies and/or medications within 4 weeks prior to the Screening Visit:

    * Treatment with immunomodulators (eg, azathioprine), cy-totoxic drugs (e.g., cyclophosphamide, vinblastine, chlo-rambucil, methotrexate) or interferons/interferon induc-ers.
    * Treatment with systemic medications that suppress the im-mune system (e.g., cyclosporine, prednisone, methotrex-ate, alefacept, infliximab).
  * Use of systemic retinoids (e.g., isotretinoin, acitretin, bexaro-tene) within 6 months prior to the Screening Visit.
  * Skin disease (e.g., atopic dermatitis, psoriasis, eczema) or con-dition (e.g., scarring, open wounds) that, in the opinion of the investigator, might interfere with the study conduct or evalu-ations, or which exposed the subject to unacceptable risk by study participation.
  * Other significant uncontrolled or unstable medical diseases or conditions that, in the opinion of the Investigator, would have exposed the subject to unacceptable risk by study participa-tion.
  * Pregnancy or lactation
  * Excessive exposure to UV radiation during study period.