This clinical trial is focused on studying a condition known as Myelodysplastic Syndrome (MDS), which affects the blood and bone marrow. Specifically, the study targets individuals with low- or intermediate-risk MDS, as classified by a system called the International Prognostic Scoring System-Revised (IPSS-R). The treatment being tested is an oral medication called Azacitidine, available in 200 mg and 300 mg tablets. This medication is being compared to a placebo, with both groups receiving the best supportive care available.

The purpose of the study is to evaluate the safety and effectiveness of Azacitidine in treating MDS. The study is divided into two parts. In the first part, different doses of the medication will be tested to find the most effective and safe dose. In the second part, the chosen dose will be compared to a placebo to see how well it works in improving the condition. Participants will take the medication orally, and the study will monitor their response over several cycles of treatment.

Throughout the study, participants will be closely observed to assess any changes in their condition and to ensure their safety. The study aims to determine if Azacitidine can help achieve a complete response, which means a significant improvement in blood cell counts and overall health. The results will help in understanding the potential benefits of this treatment for people with low- or intermediate-risk Myelodysplastic Syndrome.