Experts have cautioned that the hype surrounding T-cell cancer therapies could be too optimistic and overlooks the cost and safety concerns surrounding the treatment.

T-cell treatment is a form of immunotherapy that involves extracting a patient's own T-cells, engineering them to fight cancer, and then re-introducing them into the body. Results released earlier this week showed that it induced complete remission in 94% of terminally ill patients with acute lymphoblastic leukaemia – which lead researcher Stanley Riddell termed “unprecedented in medicine”. The breakthrough was widely reported by the media.

However, Cai Xuan, GlobalData’s Analyst covering Oncology and Hematology, has said that the optimism must be approached with caution: “The cost of T-cell therapy is currently estimated at a staggering $300,000 per patient, with some estimates pegging the cost at over $500,000,” she says. “Given this, T-cell therapies must show curative ability in order to justify such a high price tag in comparison to existing treatment options such as stem cell transplantation, which can cost from around $100,000 to $200,000.

“In order to do this, more trials must be conducted. To date, only a handful have gone ahead, in a limited number of patients, due to the high cost, as well as the long and difficult manufacturing processes involved in administering T-cell therapy. This presents a huge scalability problem which cannot easily be solved.”

She adds that T-cell therapy currently has a poor safety profile. Even in the limited data released so far, fatal cases of tumour lysis syndrome, cytokine release syndrome, and other organ-specific toxicities have been reported. 

Xuan continues: “The aggressive nature of T-cell therapy’s side effects means it is highly unlikely to replace current frontline therapy options. On top of this, the lack of long-term follow-up data presents the danger of additional long-term toxicities being revealed in the future.

“Data suggesting impressive remission rates of up to 90% in treated patients are preliminary, and it is still too early to tell if these remissions will turn into cures. T-cell therapy is undoubtedly a significant step forward for immunotherapy, but whether it will reach the status of a breakthrough cure remains to be seen.”

Meanwhile, in a blog Cancer Research UK’s Nick Peel notes that the patients recruited to these studies had very advanced cancers and were projected to have only two to five months to live.

“For most people with these cancers, there are highly effective treatments available,” he says. “So it’s important to view these latest findings as part of a bigger picture. Only with further research will we truly understand the role this type of immune cell therapy might play in treating these cancers.”

Read the CRUK blog here.