A Study of Oleogel-S10 Gel for the Treatment of Radiation Dermatitis in People With Breast Cancer

Inclusion Criteria:

* Patients who are receiving PMRT to the chest wall or post-lumpectomy RT to the whole breast cancer of any stage
* Age ≥ 18 years
* Patients who develop ARD grade 2/3 after fraction day 20 (when receiving 25 total fractions) or after fraction day 25 when receiving (30 total fraction inclusive of a 5 fraction boost) of radiation therapy with all locations of desquamation
* Able to self-administer topical interventions or provide for another person to apply the topical intervention
* Patients may be started on any topicals prior to study enrollment. Once patient is enrolled on study (on or before Day 1), patient must be able to discontinue other topicals (including topical steroids, Silvadene, calcineurin inhibitors) to the treatment area
* Patients have completed surgery or chemotherapy ≥ 4 weeks prior to start of radiation therapy. Patients may receive antibody-drug conjugates at any time before/during/after study
* Women of childbearing potential (WCBP) must have a negative serum pregnancy test at Screening and a negative urine pregnancy test at Baseline (Day 0) and documented monthly.
* WCBP must agree to abstrain from sex or use a highly effective method of birth control\* from the time of consent through visit 5.

  * Adequate contraceptive methods include those with a low failure rate, i.e., less than 1% per year, when used consistently and correctly, such as abstinence from sexual intercourse, and some double barrier methods (condom with spermicide) in conjunction with use by the partner of an intrauterine device, diaphragm with spermicide, oral contraceptives, birth control patch or vaginal ring, or injectable or implanted contraceptives. Abstinence is acceptable only as true abstinence: when this is in line with the preferred and usual lifestyle of the subject. Periodic abstinence (e.g., calendar, ovulation, symptothermal, post-ovulation methods) and withdrawal are not acceptable methods of contraception.

A woman that is postmenopausal (≥2 years since last menstrual period) or permanently sterilized (e.g., tubal occlusion, hysterectomy, bilateral salpingectomy) is not considered a WCBP.

Exclusion Criteria:

* Patients who are receiving radiation therapy for inflammatory breast cancer or malignant fungating wound
* Known history of allergy to any ingredient of the study medication
* Patients with collagen-vascular disease/vasculitis
* Patients receiving hypofractionated radiation therapy
* Special populations:

  * patients who, in the opinion of the investigator have a condition that precludes their ability to provide an informed consent