**Study Overview:** **Complex Regional Pain Syndrome Type 1 (CRPS-1)** is a painful condition affecting one limb. This study tests a new treatment called **IV AMBTX-01 (neridronate)**, administered through a vein, to see if it helps with the "warm" subtype of CRPS-1. **IV** stands for intravenous, meaning the medicine goes directly into your blood through a needle. A **positive triple phase bone scan (TPBS)** confirms the type of CRPS-1. **Study Details:** Participants will be in the study for about **18 weeks**, starting with a **6-week screening** to ensure they meet the study requirements. Treatment involves receiving the medicine on **Days 1, 4, 7, and 10**, followed by a **12-week follow-up** to monitor results. **Key Points:** - **Eligibility:** You must be at least 18, meet specific CRPS-1 criteria, and have had CRPS symptoms for no more than 6 months. - **Exclusions:** You can't join if you have other types of CRPS, severe health issues, or have taken neridronate before. - **Risks & Requirements:** Women must use effective birth control, and some medicines and therapies aren't allowed during the study.