Ashley Davalos, Assistant Director at Ionis Pharmaceuticals, delivered this presentation on the development and validation of a universal in-process assay method for oligonucleotide determination via slope spectroscopy. Davalos began by introducing Ionis Pharmaceuticals, highlighting its thirty-year legacy as a leader in RNA-targeted therapeutics, with a robust pipeline of commercial medicines and clinical programmes. The presentation outlined the fundamental principles of oligonucleotide technology, focusing on antisense oligonucleotides (ASOs) and siRNA, their synthetic origins, and mechanisms of action in gene regulation.
The manufacturing process for oligonucleotide drug products was described in detail, emphasising the critical role of in-process assay methods. Davalos explained that accurate assay measurements are essential to avoid over- or under-dilution of drug batches, which can impact product quality and regulatory compliance. Conventional methods such as HPLC-UV were contrasted with the SoloVPE instrument, which is now favoured for its speed, simplicity, and adaptability.
A key innovation discussed was the universal assay method using the SoloVPE instrument. This approach leverages variable path length spectroscopy, allowing for rapid and precise quantification of oligonucleotides. The method’s universality is achieved by employing a reference standard, ensuring consistency across different compounds and concentrations. Method optimisation was a significant focus, with Davalos detailing the use of design of experiments (DOE) to refine parameters such as wavelength, absorbance threshold, and sample dilution. The optimal sample concentration was determined to be 0.1 mg/ml for ASOs, balancing accuracy and minimising intermolecular interactions.
Validation results were presented in accordance with ICH guidelines, demonstrating excellent linearity, accuracy, and precision across multiple sites and analysts. The SoloVPE method showed tight recovery rates and reproducibility, outperforming traditional HPLC methods in terms of efficiency and ease of use. Robustness testing confirmed the method’s reliability under various operational scenarios.
In conclusion, Davalos asserted that the universal assay method developed at Ionis Pharmaceuticals is now integral to commercial manufacturing processes. This advancement supports the consistent delivery of high-quality oligonucleotide medicines, reducing uncertainty and enhancing drug development efficiency. The ongoing use of this method positions Ionis at the forefront of innovation in RNA therapeutics.
