CAR-T for lupus
CAR-T is a cell therapy that has made waves in the treatment of some blood cancers. It harnesses the natural capacity of important immune cells called T cells, and genetically modifies them to better target cancer.
In the UK, several CAR-T therapies are approved in the treatment of B cell cancers that have failed to respond to other treatments. CAR-T therapy has provided a lifeline to patients who otherwise would have limited treatment options – but its potential may go further than that.
A recent clinical trial of a CAR-T therapy on six patients with severe lupus, an autoimmune condition, hints towards just one application of CAR-T outside blood cancers.
How CAR-T works
The ‘CAR’ in CAR-T stands for the crucial addition made to the T cells which helps them better target cancer. The ‘Chimeric Antigen Receptor’ can be thought of as a specially designed fishing hook that can target a specific molecule. Once CAR T-cells find their target, they initiate an immune response which kills their target cells.
In the case of blood cancers, CAR-T has been most effective in treating B cell cancers because ‘CAR’s can be made which specifically target B cells, and the body can build back up its supply of healthy B cells with relative ease after the treatment.
How is it treating lupus?
‘Obe-cel’ is the name of the most recently approved CAR-T therapy in England and Wales, where it can be used to treat B-cell acute lymphoblastic leukaemia in patients aged 26 and over who have not responded to other treatments.
Now, a clinical trial has shown that obe-cel also has potential in the treatment of lupus, an autoimmune condition that can be debilitating and even fatal.
The causes of lupus are not fully understood, but genetic and environmental factors are thought to be involved. It’s a difficult disease to diagnose, as its symptoms vary and can overlap with many other conditions – but generally patients with lupus suffer from chronic symptoms including fever, fatigue, skin rashes and joint pain.
In lupus, the immune system starts attacking friendly cells, and key players in this ‘friendly fire’ are the antibody-producing B cells. Because CAR-T therapies like obe-cel target B cells, clinicians thought these might be good candidates for treatment in the most severe cases of lupus.
The CARLYSLE Phase 1 clinical trial, which released early findings this month, showed that of six patients treated with obe-cel, five were in remission from lupus in the months following the treatment.
Yasmin Sheikh, head of policy and public affairs at the stem cell charity Anthony Nolan, said:
At Anthony Nolan, we’ve seen how transformative CAR T-cell therapy can be for people with blood cancer.
We’re very excited to see these results which highlight the potential for CAR T-cell therapy to also benefit people living with autoimmune conditions.
While these findings are highly encouraging, attention must turn to how these innovative treatments can be delivered in practice. The NHS must ensure that it has the workforce and infrastructure in place so that patients can benefit from these new therapies without delay.
Where to next
Whether CAR-T could be used as a wider treatment for lupus and other autoimmune conditions is being investigated around the world. In the UK, a similar trial is underway to see whether CAR-T could also treat multiple sclerosis.
In all cases, what still needs to be seen is how long the positive effects of the therapy last, and how the therapy might need to be specifically adapted to treat different conditions.
The expansion of CAR-T in the treatment of blood cancers and even solid tumour cancers holds much potential. Once researchers understand more about how to best use these super-charged T cells to treat different diseases, we could see CAR-T become a standard treatment option for many different cancers and immune conditions.