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

NCT07471880 | Active Not Recruiting Phase 2

• 1 other identifier: LBRC-RAB001-201
• Study Type: interventional
• Target: 161
• Locations: 1 country
• Sites: 1

Brief Summary

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. 1.. Change in femoral head necrotic lesion volume at 48 weeks (MRI)
2. 2.. Change in hip function score at 48 weeks (HHS, Harris Hip Score)

Conditions

Osteonecrosis; Osteonecrosis of the Femoral Head

Keywords

RAB001; LLP2A-Alendronate; Osteonecrosis of the Femoral Head

Outcome Measures

Primary Outcomes (2)

• Changes in Necrotic Area Volume of the Femoral Head (MRI)

  week48

• Changes in Hip Function Scores (HHS)

  It is a clinical tool widely used to assess hip function and pain levels. The scoring system is administered by physicians through questionnaires and physical examinations, covering multiple dimensions such as pain, function, deformity, and range of motion.Higher scores indicate milder symptoms in patients, with a maximum of 100 points and a minimum of 0 points.

  week48

Secondary Outcomes (8)

• Changes in the volume of the femoral head necrotic area (MRI)

  week24

• Changes in Hip Function Scores (HHS)

  week24

• Changes in bone mineral density (DEXA) of the proximal femur (total hip) and lumbar spine (L1-L4)

  week24and week48

• Rate of non-collapse of the femoral head(defined as femoral head collapse ≤ 2mm based on hip CT + MRI examination)

  week24 and week48

• Time to progression of osteonecrosis in the target-side femoral head compared to baseline (defined as femoral head collapse > 2mm based on hip CT + MRI examination)

  week48

Study Arms (4)

High-dose

EXPERIMENTAL

Intravenous infusion RAB001 1200μg/kg

Drug: RAB001 high dose

Medium-dose

EXPERIMENTAL

Intravenous infusion RAB001 750μg/kg

Drug: RAB001 medium dose

Low-dose

EXPERIMENTAL

Intravenous infusion RAB001 400μg/kg

Drug: RAB001 low dose

Alendronate

ACTIVE COMPARATOR

Drug: Alendronate (Fosamax)

Interventions

RAB001 high dose DRUG

Intravenous infusion RAB001 1200μg/kg

High-dose

RAB001 medium dose DRUG

Intravenous infusion RAB001 750μg/kg

Medium-dose

RAB001 low dose DRUG

Intravenous infusion RAB001 400μg/kg

Low-dose

Alendronate (Fosamax) DRUG

Alendronate 70mg weekly

Alendronate

Eligibility Criteria

• Age: 18 Years - 69 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• years ≤ age ≤ 69 years, gender not limited;
• Patients with glucocorticoid-induced osteonecrosis of the femoral head (ONFH) according to the 2019 edition of the "Guidelines for clinical diagnosis and treatment of osteonecrosis of the femoral head in adults", with an ARCO stage of II, and confirmed by CT and MRI examinations to have no femoral head collapse, and the time from first glucocorticoid use to the screening period must exceed 30 days;
• The participant has no plans for hip surgery on the target side within the next 54 weeks;
• Participants with unilateral or bilateral ONFH are not restricted. For unilateral involvement, the affected side (as the target side) must have no femoral head collapse confirmed by hip CT examination. For bilateral involvement, hip CT examination must confirm that at least one side has no collapse (the non-collapsed side is the target side; if both sides are necrotic and neither has collapsed, the side with more severe necrosis is the target side. If the contralateral side of the target side meets the criteria for study-defined osteonecrosis, all study information must be recorded for that side as for the target side);
• Participants must be informed about the study and voluntarily sign a written informed consent form before the trial.

You may not qualify if:

• BMI ≥ 35 kg/m²;
• The target-side osteonecrosis of the femoral head (ONFH) is classified as type M according to the China-Japan Friendship Hospital (CJFH) classification;
• Inability to walk or to complete all the examinations, treatments, and follow-ups required by the trial protocol;
• Currently receiving glucocorticoid pulse therapy;
• Severe metabolic diseases, cardiovascular diseases, clinically significant atrial fibrillation, uncontrolled hypertension, uncontrolled asthma, symptomatic pulmonary fibrosis, recent gastrointestinal bleeding requiring transfusion, mental or psychological disorders;
• History of deep vein thrombosis, with any invasive preventive/therapeutic measures taken within the last five years;
• Current fracture or infection in either hip joint, or previous surgery on the target-side hip joint;
• Planned oral surgery within 54 weeks after enrollment;
• Known hereditary bone diseases, such as achondroplasia, osteogenesis imperfecta, hypophosphatemic rickets, etc.;
• Use of medications for bone metabolic diseases, integrins, α4β1 inhibitors/antagonists, or anti-VEGF drugs within 6 months or 5 half-lives (whichever is longer) prior to screening, as detailed in section 12.7;
• Participants who have received opioid analgesics, non-steroidal anti-inflammatory drugs (NSAIDs), or other pain medications within 5 half-lives prior to screening;
• Comorbidities that, in the investigator's judgment, may affect the clinical efficacy assessment of the hip joint, such as knee osteoarthritis, scoliosis, pelvic or lower limb deformities, etc.;
• Previous allergy or contraindication to alendronate;
• Any of the following abnormal laboratory findings during screening:
• Phosphate level \< LLN; Patients with decompensated liver function (e.g., complications of portal hypertension such as ascites, gastroesophageal variceal bleeding, sepsis, hepatic encephalopathy, hepatorenal syndrome, etc.); Estimated glomerular filtration rate (eGFR) \< 35 mL/min/1.73 m² (calculated based on creatinine using the CKD-EPI Creatinine 2009 Equation); Hemoglobin \< 100 g/L; Prolonged QT interval (male \> 450 msec, female \> 470 msec).

Sponsors & Collaborators

• ZhongShan LaiBo RuiChen BioMedicine Co.,Ltd.: lead

Study Sites (1)

ZhongShan LaiBo RuiChen BioMedicine Co.,Ltd.

Zhongshan, Guangdong, 528400, China

Location

MeSH Terms

Conditions

Osteonecrosis; Legg-Calve-Perthes Disease

Interventions

Alendronate

Condition Hierarchy (Ancestors)

Bone Diseases; Musculoskeletal Diseases; Necrosis; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Femur Head Necrosis

Intervention Hierarchy (Ancestors)

Diphosphonates; Organophosphonates; Organophosphorus Compounds; Organic Chemicals

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER GOV
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: February 28, 2026
• First Posted: March 13, 2026
• Study Start: December 24, 2024
• Primary Completion (Estimated): October 10, 2026
• Study Completion (Estimated): February 28, 2027
• Last Updated: March 24, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will not share

Locations

CN (1)