A Phase II Trial of RAB001 (LLP2A-Alendronate) for Steroid-Induced Early-Stage Osteonecrosis of the Femoral Head

This is a multicenter, randomized (similar to drawing lots, where the treatment you receive is not chosen by you or the researchers), controlled, blinded (the three dose groups of the investigational drug are blinded, meaning neither you nor the blinded researchers will know which dose you are receiving) clinical study to evaluate the efficacy, safety, and PK/PD profiles of RAB001 for injection in patients with early-stage non-traumatic osteonecrosis caused by long-term glucocorticoid use. A parallel-group enrollment design will be used, with a total of approximately 160 subjects expected to be enrolled (High-dose A: 1200 μg/kg；Medium-dose B: 750 μg/kg ；Low-dose C: 400 μg/kg): Control group (D: Alendronate Sodium Tablets (Fosamax) 70 mg orally once weekly) = 40 cases . If you agree to participate in this trial, you will have a 25% chance of being assigned to one of the groups mentioned above. Supportive treatment: Calcium (recommended dose: 1000-1200 mg/d) + Vitamin D (recommended dose: 600-800 IU/d). The study physician may choose the appropriate dosage of calcium and vitamin D based on the subject's specific conditions. Primary endpoints: 1. . Change in femoral head necrotic lesion volume at 48 weeks (MRI) 2. . Change in hip function score at 48 weeks (HHS, Harris Hip Score)