Promising US-based startup Wugen has announced it has raised $172m in a recent Series B financing round. The company intends to use the funds to further its impressive pipeline of natural killer (NK) cell therapies, including initiating a Phase I/II trial for lead candidate WU-NK-101 in acute myeloid leukaemia (AML) and myelodysplastic syndromes, as well as beginning multiple new trials in solid tumours. Wugen also intends to advance its next-generation CD7-targeting chimeric antigen receptor (CAR) T cell therapy in T-cell acute lymphoblastic leukaemia (T-ALL).
There is much hype surrounding the prospect of off-the-shelf cellular therapy, and NK cell therapies, in particular, appear to offer potentially good efficacy, combined with more limited side effects compared to currently available CAR-T cell therapies. Wugen is pinning its hopes on memory-like NK cells, which the company claims have the potential to be more potent than conventional NK cells. NK cells are harvested from healthy individuals, removing the need for long manufacturing times associated with autologous therapies. Cells are then activated with interleukin-12, 15 and 18, resulting in their being differentiated into memory-like cells that can exhibit potent anti-tumour responses.
Results of a Phase I trial published in 2016 hint at the potential of memory NK cells. In the trial, relapsed or refractory AML patients were infused with donor NK cells followed by interferon activation. Of the nine evaluable patients, five clinical responses were seen, including four complete responses. Wugen has also published promising preclinical results of NK products in T-ALL. While CAR-T therapy is available in B-cell ALL, cell therapy development for T-ALL has lagged. T-ALL patients who relapse or are refractory to first-line treatment have a poor prognosis and limited therapeutic options. An effective cell therapy in this indication, therefore, has the potential to address a major unmet need.
Cell therapies for solid tumours have proven to be significantly challenging to develop. Wugen also hopes, however, that NK cells can be of use in these settings. Notable is the fact that preclinical data in mouse models indicate that memory NK cells are more effective than conventional NK cells at inducing an immune response against melanoma tumours. Wugen has indicated that a Phase I trial will be initiated in this, as well as other solid tumour indications, at the end of the year.
CAR-T cell therapies have been transformative in several haematological cancers, offering a potential cure to patients who would otherwise have had very limited options. There are, however, multiple factors that limit their use, notably their very high cost and the logistical challenges associated with delivery, including the need for patients to travel potentially long distances to specialised treatment centres and for physicians to be very familiar with adverse events. As well as this, not all patients are eligible for CAR-T therapy.
For those with rapidly progressing forms of the disease, or with certain bone marrow deficiencies, product cannot typically be manufactured quickly enough or even at all. There is, therefore, a significant unmet need for a greater number of options for these patients. An effective off-the-shelf cell therapy would be a significant advance and could complement currently available CAR-T therapies by acting as a bridging therapy that patients could receive, if necessary, while awaiting the production of their CAR-T product, or be used in patient groups for which CAR-T is unsuitable. The wealth of promising preclinical and early clinical data, combined with this newest batch of funding, will help Wugen advance this exciting technology in a multitude of indications.