(Treatments to shrink tumors before surgery, radiation or other forms of nondrug therapy) to use the investigational drug (Darovasertib) in patients with a type of cancer in the middle of the eye wall.

You may be able to join if

• Must be at least 18 years of age.
• Is able to provide written, informed consent before initiation of any study-related procedures, and is able, in the opinion of the Investigator, to comply with all the requirements of the study.
• Has an initial primary diagnosis of localized UM (no evidence of distant and/or extraocular disease) as clinically determined by the treating Investigator, with a plan to undergo either enucleation or plaque brachytherapy. (Note: Patients with local relapse after prior primary therapies are excluded.) Tumor must be able to be completely imaged by ocular ultrasound and color fundus photography for accurate tumor measurements and distance to vital eye structures, such as the fovea and optic disc. • Cohort 1: o Clinically diagnosed uveal (not iris) melanoma in which enucleation is recommended and meets the following criteria:  > 10 mm in thickness (or in regions where non-I125 plaque is standard of care, > 6 mm for non-I125 plaques)  Tumor must not exceed 16 mm in LBD to be considered eligible. o NOTE: The cancer cannot have attributes that necessitate enucleation regardless of response to therapy (e.g., extraocular disease, hemorrhage; blind painful eye; evidence of optic nerve invasion to an extent that despite tumor shrinkage eye preservation is not reasonably expected; etc.) • Cohort 2: o Clinically diagnosed uveal (not iris) melanoma in which plaque brachytherapy is recommended, meets the following criteria, and places the patient at significant risk of loss of useful vision in the affected eye:  4-10 mm in thickness (or in regions where non-I125 plaque is standard of care, 4-6 mm for non-I125 plaques)  Tumor must not exceed 16 mm in LBD to be considered eligible. • Cohort 2: o Clinically diagnosed uveal (not iris) melanoma in which plaque brachytherapy is recommended, meets the following criteria, and places the patient at significant risk of loss of useful vision in the affected eye:  4-10 mm in thickness (or in regions where non-I125 plaque is standard of care, 4-6 mm for non-I125 plaques)  Tumor must not exceed 16 mm in LBD to be considered eligible. o NOTE: Sub-foveal or > 180-degree optic nerve involved tumors are excluded. At least 10 subjects from Cohort 2 will participate in the PK substudy. • Cohort 3: o Clinically diagnosed uveal (not iris) melanoma that is < 4 mm in thickness requiring treatment  Tumor must not exceed 12 mm in LBD to be considered eligible. o NOTE: at least half the subjects must have a tumor that is ≤ 3 mm in thickness. Approximately 10 subjects in Cohort 3 will participate in the PK substudy. Lesions that are indeterminate or are nevi are excluded.
• Able to safely swallow orally administered medication.
• Has available prognostication results assessed by local standards, or patient must be willing to submit sample(s) (prior to neoadjuvant therapy or at the time of PLT) for local or central laboratory prognostication testing. If prognostication results are not available and sample(s) cannot be collected, a patient may be enrolled only after approval by the Medical Monitor.
• Has Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1 (Appendix 4, [Section 14.4]) (or Karnofsky ≥70%).