Serotype Expansion Of GMP Platform Replication Competent Adeno-Associated Virus (rcAAV) Method

By Kaitlyn J. Knapp, Anandhakumar Jayamani, Steven Henry, Alexander Chiappini, Stacie Fichthorn, Marian L. McKee

Regulations require replication-competent virus testing to ensure the safety of vector-based gene therapies, which use modified Adeno-associated virus (AAV) vectors to deliver therapeutic genes. Monitoring for rcAAV is critical because viral replication could result in unintended side effects.

A study explored the applicability of a GMP (Good Manufacturing Practice) rcAAV method for AAV serotypes beyond AAV2—specifically AAV5, AAV8, and AAV9. Researchers assessed how serotype-specific factors, such as Multiplicity of Infection (MOI) and cell line tissue type, affect infectivity and present testing challenges.

The current method successfully detected replication competence in AAV9, but not in AAV5 and AAV8, possibly due to their longer response times and lower infection sensitivity. The study highlights that amending the platform to accommodate the varied infection sensitivity and response time of AAV5 and AAV8 may show success. These results and future experiments will expand the capabilities of rcAAV assays and the diversity of AAV vector therapeutics that can undergo GMP safety testing.

Understand the impact of serotype-specific factors on AAV infectivity and learn about the proposed next steps for method expansion.