Peter E. Larsson
Global Director Regulatory Affairs, PolyPeptide Group

Abstract

Synthetic peptides are increasingly used in vaccines. Specific regulatory guidance with respect to CMC for peptide drug substances is limited. The article discuss the regulatory requirements and industry experience for synthetic peptides in general and in vaccine products specifically

INTRODUCTION

There is a strong interest in vaccines composed of synthetic peptides, especially for cancer treatment and immunotherapy. As the peptide is normally of short to medium chain-length and the required quantity low, synthetic peptide vaccines have advantages over those vaccines manufactured by biological methods -  they are relatively low in cost, of high purity, and the manufacturing process is less complex. Currently, hundreds of vaccine clinical trials with synthetic peptides are ongoing with some programs approaching the registration phase. So far, there is substantial regulatory experience from the clinical phases, but not from the registration phase. 

From a regulatory standpoint, a synthetic peptide drug substance in a vaccine falls in a grey area. The peptide drug substance is neither fully classified as a small molecule nor as a biologic. This is, however, something the peptide industry is used to. What additionally complicates the situation in the case of vaccines is that they are classified by the US-FDA as biological drug products handled by CBER (Center for Biologics Evaluation and Research, FDA) while synthetic peptides t ...