CAR T-cell therapies have shown transformational potential for the treatment of cancer, generating excitement among researchers and oncologists. Six CAR T drugs have been approved by the FDA since 2017, and many are in clinical evaluation. BioStock takes a closer look at this emerging and promising form of cancer treatment.

For decades, the only options for treating cancer were surgery, chemotherapy and radiation therapy. Today, these continue to be a first line of attack against the life-threatening disease. However, a new category of treatment has emerged over the last 10-15 years, giving new hope to cancer patients: immunotherapy.

Immunotherapy represents a class of drugs designed to boost a patient’s immune system. This reinforcement helps the patient fight off diseases that have a way of circumventing immune defence mechanisms. Cancer is one of those diseases. It hides from our immune system by mimicking normal, healthy cells.

One of the most common and perceived as most promising types of immunotherapy at the moment is checkpoint inhibitors. These antibodies expose cancer cells to immune cells called T-cells. While this class of immunotherapy has broad appeal in the oncology world, they are not always effective, and can induce quite severe side effects in some patients.

The rise of CAR T-cell therapies

More recently, another class of immunotherapy has emerged: CAR T-cells. Considered revolutionary in the oncology field and nominated as 2018’s Advance of the Year at ASCO (American Society of Clinical Oncology), CAR T therapies work by genetically modifying T-cells extracted from a patient’s blood. The modification enables the expression of the chimeric antigen receptor (CAR), which is designed to recognise and bind to the specific cancer cells found inside the patient. The redesigned T-cells are then infused back into the patient’s bloodstream. Here, they can actively seek out and kill cancer cells.

This personalised treatment approach has shown remarkable results in clinical trials, with many patients experiencing complete remission. The first CAR T-cell therapies were approved by the FDA in 2017: Novartis’ Kymriah and Gilead Science’s Yescarta. Both are for the treatment of B-cell lymphoma. Since then, four new approvals have followed targeting a variety of blood cancers.

A prime example of CAR T success in the Nordics

According to an article published last month in the Swedish newspaper Sydsvenskan, in 2020, Skåne’s University Hospital (SUS) in Sweden was the first in the Nordic region to implement marketed CAR T therapies as part of treatment regimens for cancer patients. Since then, more than 20 patients with different types of blood cancer, including lymphoma, have undergone CAR T treatment at SUS.

In a statement to Sydsvenskan, Professor Mats Jerkeman, senior physician at the SUS oncology department, said that approximately half of the patients no longer show any traces of the disease. While there is still room for improvement, these results represent a major step in the right direction. According to Professor Jerkeman, these patients would have had a much grimmer prognosis without these therapies.

High costs represent major limitation for CAR T

CAR T therapies approved so far come with a strong safety profile. However, a major limitation exists: the cost. According to Sydsvenskan, these treatments can cost several million kronor per patient. This makes them a last resort type of option for now. The high cost also increases waiting times for approval for each patient, putting at risk patients with fast-spreading disease.

However, the high cost can be weighed against the prospect of long-term remission. For example, Novartis’ Kymriah, which is a one-time treatment for B-cell acute lymphoblastic leukaemia (ALL), has shown an 83 per cent remission rate after three months in patients that do not respond to standard treatments. This could translate to not only lesssuffering for patients, but also reduced overall societal burden.

For this reason, CAR T therapies remain one of the most promising cancer treatments on the market, so the market potential is significant. In fact, according to a report by Pharmaceutical Technology, CAR-T cell therapies is one of the fastest growing and potentially profitable therapeutic areas in oncology. The report shows a market size expected to reach 25 billion USD by 2028. This translates to a CAGR of over 47 per cent during the forecast period. The expected rise in cancer incidence will make the need for new treatments even greater.

Finding ways to boost CAR molecules

One thing is for sure, CAR T therapies have the potential to make a significant impact in the oncology field. Researchers are on the continuous pursuit of improving CAR T technology. Their aim is to find new and better ways of arming CAR molecules for more efficient binding to cancer cells.

A great example is Elicera Therapeutics – currently the only Swedish biotech developing CAR T therapy candidates. The company is based on the research from Professor Magnus Essand and his team at Uppsala University, and clinical studies with one of their candidates – ELC-301 – are expected to begin this year.

Globally, hundreds of CAR T candidates are being evaluated in clinical trials. Through continued research and development, this rising technology could be the answer that cancer patients have been waiting for.