Abstract: This last decade, chimeric antigen receptor (CAR) T-cell therapy has become a real treatment option for patients with B-cell malignancies, while multiple efforts are being made to extend this therapy to other malignancies and broader patient populations. However, several limitations remain, including those associated with the time-consuming and highly personalized manufacturing of autologous CAR-Ts. Technologies to establish “off-the-shelf” allogeneic CAR-Ts with low alloreactivity are currently being developed, with a strong focus on gene-editing technologies. Although these technologies have many advantages, they have also strong limitations, including double-strand breaks in the DNA with multiple associated safety risks as well as the lack of modulation. As an alternative, non-gene-editing technologies provide an interesting approach to support the development of allogeneic CAR-Ts in the future, with possibilities of fine-tuning gene expression and easy development. Here, we will review the different ways allogeneic CAR-Ts can be manufactured and discuss which technologies are currently used. The biggest hurdles for successful therapy of allogeneic CAR-Ts will be summarized, and finally, an overview of the current clinical evidence for allogeneic CAR-Ts in comparison to its autologous counterpart will be given.
Genome engineering technologies are powerful tools in cell-based immunotherapy to optimize or fine-tune cell functionalities. However, their use for multiple gene edits poses relevant biological and technical challenges. Short hairpin RNA (shRNA)-based cell engineering bypasses these criticalities and represents a valid alternative to CRISPR-based gene editing. Here, we describe a microRNA (miRNA)-based multiplex shRNA platform obtained by combining highly efficient miRNA scaffolds into a chimeric cluster, to deliver up to four shRNA-like sequences. Thanks to its limited size, our cassette could be deployed in a one-step process along with all the CAR components, streamlining the generation of engineered CAR T cells. The plug-and-play design of the shRNA platform allowed us to swap each shRNA-derived guide sequence without affecting the system performance. Appropriately choosing the target sequences, we were able to either achieve a functional KO, or fine-tune the expression levels of the target genes, all without the need for gene editing. Through our strategy we achieved easy, safe, efficient, and tunable modulation of multiple target genes simultaneously. This approach allows for the effective introduction of multiple functionally relevant tweaks in the transcriptome of the engineered cells, which may lead to increased performance in challenging environments, e.g., solid tumors.
Mont-Saint-Guibert, Belgium – Celyad Oncology (Euronext & Nasdaq: CYAD) (the “Company”), a biotechnology company focused on the discovery and development of innovative technologies for chimeric antigen receptor (CAR) T-cell therapies, today announces the publication of the data from the haematological arm of the THINK study which evaluated CYAD-01 in relapsed or refractory (r/r) acute myeloid leukaemia (AML) and myelodysplastic syndromes (MDS) or multiple myeloma (MM) patients. The findings were published in the journal The Lancet Haematology.
CYAD-01 is the Company’s first autologous CAR T-cell candidate, based on the natural killer receptor NKG2D, assessed clinically. The completed THINK study was an open-label, dose-escalation Phase 1 study for patients with r/r AML, MDS, or MM, after at least one previous line of therapy. Patients were recruited from five hospitals in the USA and Belgium.
The Lancet Haematology publication includes data from the 16 patients treated with CYAD-01 in the dose escalation segment of the study, which evaluated three dose levels of CYAD-01 using a schedule of three infusions at two-week intervals in the absence of any preconditioning chemotherapy. Overall, CYAD-01 showed favourable safety data with signs of clinical activity with three of the 12 evaluable AML/MDS patients presenting an objective response.
Importantly, the THINK study is one of the first completed dose-escalation CAR T-cell studies in r/r AML/MDS. Unlike the majority of the studies evaluating CAR T-cell therapy candidates, the THINK study evaluated multiple infusions of CYAD-01 as a stand-alone product candidate (i.e., without prior bridging or preconditioning chemotherapy). This feature is of particular interest considering the median older age and the poorer general condition of patients with r/r AML or MDS at diagnosis.
Although the need to improve the anti-tumour activity is warranted, these data in a difficult-to-treat patient population potentially provide the proof-of-concept of targeting NKG2D ligands by a CAR T-cell product candidate, and support the further development of NKG2D-based CAR T-cell therapies.