A Randomized, Double-blind, Placebo-controlled Phase 3 Study of Tamibarotene Plus Azacitidine Versus Placebo Plus Azacitidine in Newly Diagnosed, Adult Patients Selected for RARA-positive Higher-risk Myelodysplastic Syndrome (SELECT MDS-1)

A subset of participants have MDS characterized by an overexpression of the RARA gene. A blood test will be used to identify participants with RARA-positive MDS. Assessment of the RARA biomarker for study eligibility will be done by collection of blood samples from potential study participants at the pre-screening visit and testing at a central laboratory. Participants who meet eligibility requirements will be randomized 2:1 to receive either Tamibarotene plus azacitidine or placebo plus azacitidine.

Key Inclusion Criteria:

1. Participants must be at least 18 years old at the time of signing of an informed consent.
2. Participants must be RARA-positive based on the investigational assay.
3. Participants must be newly diagnosed with HR-MDS as follows:

   Diagnosis of MDS according to the World Health Organization (WHO) classification (Arber 2016) and classified by the Revised International Prognostic Scoring System (IPSS R) risk category as very high, high, or intermediate risk.

4. Participants must have Eastern Cooperative Oncology Group (ECOG) Performance Status of ≤2.

Key Exclusion Criteria:

1. Participants are suitable for and agree to undergo allogeneic HSCT at the time of Screening.
2. Participants who received prior treatment for MDS with any hypomethylating agent, chemotherapy or allogeneic HSCT.