Generator-produced yttrium-90 for radioimmunotherapy

Area of Science:

• Nuclear Medicine
• Radiochemistry
• Bioconjugation

Background:

• Yttrium-90 (90Y) offers advantages for radioimmunotherapy.
• Current clinical trials often use commercially sourced 90Y, not generator-produced.
• Developing methods for in-house generator-produced 90Y labeling is crucial for clinical trials.

Purpose of the Study:

• To adapt and develop procedures for labeling antibodies with generator-produced 90Y for human use.
• To establish a safe and efficient method for preparing 90Y-labeled diethylenetriaminepentaacetic acid- (DTPA) coupled antibodies.

Main Methods:

• Utilized a strontium-90 (90Sr) radionuclide generator with Dowex 50 cation exchange resin.
• Optimized elution using ethylenetriaminetetraacetic acid (EDTA) and subsequent purification.
• Labeled DTPA-coupled antibodies with purified 90Y, achieving high specific activity.

Main Results:

• The 90Sr generator supported up to 25 mCi without radiolytic degradation.
• Elution efficiency averaged 98% with minimal 90Sr breakthrough (0.002%).
• Resulting 90Y-labeled proteins achieved high specific activity (1-3 mCi/mg) and radiochemical purity (>90%).

Conclusions:

• Developed a safe and effective method for preparing 90Y-labeled proteins from a generator.
• This technique enables the use of high-purity, generator-produced 90Y for radioimmunotherapy.
• The prepared 90Y-labeled antibody conjugates are suitable for patient administration.