The purpose of this study is to assess the safety, tolerability, and efficacy of BMS-986158 alone and in combination with either Ruxolitinib or Fedratinib in participants with Dynamic International Prognostic Scoring System (DIPSS)-intermediate or high risk blood cancer. Part 1 consists of BMS-986158 in combination with either Ruxolitinib or Fedratinib and Part 2 consists of BMS-986158 in combination with either Ruxolitinib or Fedratinib and BMS-986158 alone.