Study on the Safety and Efficacy of Bimiralisib Gel in Participants Suffering From Actinic Keratosis

Key Inclusion Criteria: * Must be of at least 50 years of age, at the time of signing the informed consent. * Have a clinical diagnosis of stable, clinically typical actinic keratosis. * Have at least 3 actinic keratosis lesions contained within contiguous treatment regions of face and/or scalp and/or back of hands. * Must agree not to use any product on the treatment area during the entire course of study except for Investigator-approved cleanser, sunscreen, wash, and non-medicated makeup. * Must be willing to comply with sun avoidance measures for all exposed areas including use of Investigator-approved sunscreen and/or hats, have limited sun exposure time, and have no tanning bed use. * Must be in good general health (ECOG 0-1) * Participants of reproductive potential must agree to use double effective contraception from screening until 90 days after discontinuing study treatment. * Female participants who had a menstrual cycle within 2 years prior to screening must have a negative serum pregnancy test at screening and a negative urine pregnancy test on their first treatment day. * Must be capable of giving signed informed consent Key Exclusion Criteria: * Known or suspected hypersensitivity to any of the excipients of bimiralisib gel. * Clinically atypical and/or rapidly changing actinic keratosis lesions in the treatment area. * Clinical evidence of severe, uncontrolled autoimmune, cardiovascular, gastrointestinal, hematological, hepatic, neurologic, pulmonary or renal disease. * Participation in any clinical research study within 30 days of the Baseline Visit. * Cosmetic or therapeutic procedures (e.g. laser, peeling, photodynamic therapy, cryotherapy) within 4 weeks of the Baseline visit and within 2 cm of the selected treatment area. * Use of sun lamps, tanning beds, and tanning booths during the 4 weeks prior to the Baseline Visit or planned use during the study. * Use of any retinoids within 90 days of the Baseline Visit, or glucocorticosteroids, methotrexate or other anti-metabolites or nicotinamide within 28 days of the Baseline Visit. * Any systemic cancer therapy or diagnosis within 6 months of the Baseline Visit. * Any other malignancy within 5 years prior to Screening except basal or squamous cell carcinoma not in the treatment area that were treated with curative intent and are without recurrence. * Other significant uncontrolled or unstable medical diseases or conditions that, in the opinion of the Investigator, would expose the participant to unacceptable risk by study participation