Ex vivo CAR-T Therapies
With several ex vivo CAR-T therapies now approved, the use of lentiviral vectors to reprogram T-cells to fight and cure previously intractable haematological cancers is well accepted. However, concerns still exist about the safety of lentiviral vectors, especially as the transduction of residual cancer cells ex vivo remains a potential long-term risk.
Aberrant Pseudotyping
Ex vivo transduction protocols enhance the safe delivery of lentivirus by enriching and activating the patients own T-cells. If the lentivirus is aberrantly pseudotyped with a 𝛼-CD19 CAR there is the potential not only to reduce potency of transduction, but also to transduce cancer cells.
Reduction of aberrant pseudotying
The Lentitek platform can significantly reduce the expression of CAR payload within the manufacturing cell line, leading to vector with less potential to transduce B-cells. A reduction of aberrant pseudotyping will lead to higher transduction potency and better patient safety.
In vivo CAR-T Therapies
In vivo CAR-T therapy represent a huge advance existing existing ex vivo solutions. Patients benefit by being treated quickly and directly with the vector without having to undergo leukapheresis. As is the case with ex vivo T-cell transduction, if the lentivirus is aberrantly pseudotyped with the CAR, this will preferentially direct the lentivirus against the CAR target. Aberrant pseudotuping will not only significantly impact on transduction potency, but will also potentially transduce cancer cells, allowing for effective epitope escape and potential relapse.
The Lentitek system effectively reduces breakthrough expression of the CAR in the manufacturing cell line, improving quality, potency and the safety of in vivo CAR-T applications.
Gene Therapies
Lentivirus is used across a wide range of gene therapy applications where patient cells are modified ex vivo, e.g. to include blood clotting factors for haemophilia or replacement of haemoglobin for Sickle Cell Disease. Lentivirus is also used in vivo across a similar spectrum of treatments to cure genetic conditions.
The Lentitek system shows significant benefit in the reduction of LTR mediated splicing which leads to breakthrough expression of the payload (see our Science). Payloads are well known to impact on lentivirus yield through production cell toxicity, or impacting on the downstream purification process. Our unique promoter has been demonstrated to function across a range of clinically relevant payloads, brining increased production quality and consistency to the process.
Cell Therapies & Gene Editing
Many clinical stage allogeneic cell therapies have used lentivirus to modify cells in the upstream development stage. Indeed, directed gene editing technologies such as CRISPR often utilise lentiviral vectors to introduce the guide RNA and other components. Even where yield may be less critical, these payloads can still be challenging to produce, requiring additional time to troubleshoot.
The Lentitek system can bring benefit to these applications as splicing or breakthrough expression of the payload can cause issues which are time consuming to identify and resolve.