Description

The investigators hypothesize that adults with sickle cell disease (SCD) and osteonecrosis of the femoral (hip) and/or humeral (shoulder) heads will tolerate oral alendronate 70 mg administered once a week x 24 weeks (6 months). In addition to collecting safety and tolerability data on alendronate in study participants, the investigators will also measure the preliminary efficacy of alendronate using changes in the Adult Sickle Cell Quality of Life Measurement System (ASCQ-Me) Pain Impact scores from baseline to 3-months and 6-months after alendronate initiation. Serum and urine specimen will also be collected to assess changes in bone biomarkers at baseline, 3-months, and 6-months.

The investigators plan to recruit 24 adults with SCD from the University of California Davis Medical Center to this single-arm, open label, interventional study. The investigators anticipate enrolling 1-2 participants per month between Sep 2024- Dec 2025.

The study endpoints are summarized below:

• To determine the recruitment and retention rates of adults with SCD and osteonecrosis enrolled in this prospective, single-arm, open label alendronate interventional study
• To measure the safety, tolerability, and preliminary efficacy of oral alendronate in adults with SCD-related osteonecrosis over a 6-month treatment duration
• To measure changes in bone biomarkers in the serum and urine of study participants not receiving chronic red blood cell transfusions at 3 time points: baseline, 3-months, and 6-months after initiation of alendronate

The investigators' goal is to complete primary data analysis by May 2026.