Is combined immunotherapy the future of cancer treatment?

At Abu Dhabi Stem Cell Congress, leading researchers look at treatments beyond chemotherapy and radiotherapy

Leading researchers look at the potential of combined immunotherapies in cancer treatment. Photo: PA Wire

While medical advances are accelerating the fight against cancer, it continues to be the leading cause of death globally, killing about 10 million people a year, according to the World Health Organisation.

Leading researchers look beyond traditional chemotherapy and radiotherapy during the Abu Dhabi Stem Cell Centre’s second Bone Marrow Transplant and Cellular Therapy Congress on Sunday and at the potential of combined immunotherapies in cancer treatment.

Speaking to The National, Prof Yendry Ventura, chief executive of the Abu Dhabi Stem Cells Centre, advocates a comprehensive approach, stressing the need for combination immunotherapies to address cancer’s complexities.

Prof Ventura says that cancer’s diversity demands more than a one-size-fits-all treatment model, stressing that “one single intervention will not help us to address so many varieties of cancers”.

Describing what he calls the “sniper paradox,” Prof Ventura warns against focusing too narrowly on any single approach. While chemotherapy and radiotherapy will continue to play a role, Prof Ventura believes that combination immunotherapy offers the best path to a cure. “When we talk about curing diseases … you need to bring the epidemiological component,” he insists, noting that real progress will come when treatments are effective on a larger scale.

T-cell therapies targeting several cancer antigens

Dr Catherine Bollard, professor of paediatrics at Children's National Medical Centre, Washington, DC, highlights the success of CAR T-cell therapy, a way to get immune cells called T cells to fight cancer by re-engineering them in the lab, more in paediatric cases than in adults.

A 2020 study tracking children with acute lymphoblastic leukaemia, showed more than 85 per cent had complete remission after CAR T-cell treatment, while 60 per cent remained cancer-free for 12 months.

While it has worked in treating lymphoma and certain leukaemia, it has not yet turned effective in treating solid tumours. Dr Bollard explains it is because solid tumours employ a complex ecosystem – “tumour micro-environment” that “hides cancer cells from the immune system”. She compares it to a wall that current T-cell therapies struggle to breach.

She, however, remains optimistic that breakthroughs in genetic engineering could enable T-cells to penetrate these barriers. Her team is currently working on developing therapies that target several tumour antigens simultaneously, making it harder for the tumour to evade treatment. “If you have a treatment that can target multiple targets on a tumour cell, then it can’t keep up,” Dr Bollard explains.

Looking ahead, Dr Bollard envisions a future where immunotherapy becomes a frontline option rather than a last resort. “I definitely think immunotherapy is going to get more prominence,” she says, adding how CAR T-cell therapy could find a place alongside antibodies, checkpoint inhibitors and other advanced treatments.

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What tumour-infiltrating lymphocytes (TILs) can offer

Prof George Coukos, director of oncology at University Hospital of Lausanne and branch director at Ludwig Cancer Research, shares Dr Bollard’s focus on CAR T-cell therapy but sees particular promise in harnessing the body’s natural immune responses.

While CAR T-cell therapy has transformed treatment for blood cancers, he acknowledges that solid tumours – accounting for most cancer cases – pose additional challenges due to the scarcity of clear targets. Coukos's approach focuses on tumour-infiltrating lymphocytes (TILs), which are T cells naturally found in tumours.

Both TIL therapy and CAR T-cell therapy involve collecting a patient's immune cells but the key difference is that TIL cells are grown directly from a tumour whereas CAR-T cells are modified from normal T-cells found in the blood. “We take out natural immunity and turn it into a product – that is TIL therapy,” Prof Coukos explains.

Early trials of TIL therapy show promise for treating melanoma, with about half of patients responding and about a quarter achieving complete remission. Encouraging results are also emerging for lung, cervical and head and neck cancers, he adds, leading to hope for an expanded range of solid tumours.

Prof Coukos believes that within five years, researchers will have clear evidence that TIL therapy can work in more common cancers, such as colon and lung. “If we can demonstrate that, then this can be achieved within my lifetime,” he adds, hopeful that TIL therapy can be streamlined to reduce treatment time and increase accessibility worldwide.