Pharmaceutical Stability of Romiplostim: In-use Functional Study Using Microscale Thermophoresis New Strategy and...

Area of Science:

• Biochemistry
• Protein Therapeutics
• Analytical Chemistry

Background:

• Functional stability is vital for therapeutic proteins throughout their lifecycle.
• Romiplostim (Nplate®) is used for immune thrombocytopenia, but in-use stability data is limited.
• Assessing therapeutic protein stability requires robust functional assessment strategies.

Purpose of the Study:

• To evaluate the in-use functional stability of romiplostim.
• To investigate romiplostim's interaction with its target, TPO-R.
• To develop and validate a new functional assessment strategy using microscale thermophoresis (MST).

Main Methods:

• Developed and optimized microscale thermophoresis (MST) and ELISA methods for romiplostim functional stability.
• Utilized Far-UV Circular Dichroism and Intrinsic Tryptophan Fluorescence Spectroscopy to confirm conformational stability.
• Assessed in-use stability under conditions simulating hospital handling (agitation, natural light) and forced degradation (freezing, artificial light).

Main Results:

• MST and ELISA demonstrated similar stability profiles for romiplostim.
• MST detected subtle functional declines in romiplostim stability not identified by ELISA.
• MST provided insights into romiplostim binding stoichiometry, indicating a 1:2 interaction at high concentrations.

Conclusions:

• Romiplostim functionality is sensitive to light exposure, less so to agitation and freezing.
• MST serves as an orthogonal strategy to ELISA for assessing therapeutic protein functionality.
• MST offers additional data on binding dynamics and stoichiometry, applicable to various therapeutic protein studies.