Gene therapy for blood cancer shows 73 per cent response rate in clinical trials: Lancet study

An Indian-developed gene therapy for certain blood cancers has shown a 73 per cent response rate among patients in India. The results of the clinical trials were published in The Lancet Haematology journal. The study included researchers from the Indian Institute of Technology-Bombay and Tata Memorial Hospital, Mumbai.?

The gene therapy, also known as 'CAR T-cell therapy', involves modifying genes in one's T-cells, a type of immune cells to help fight cancer. For the study, the researchers looked at patients with leukaemia which occurs in bone marrow and lymphoma which affects the lymphatic system.

Researchers said in low and middle-income countries, patients in whom 'B-cell' tumours continue to grow following a period of remission (relapse), or do not respond to treatment (refractory), suffer from poor outcomes due to an absence of effective therapies.

A type of white blood cell, B-cells are crucial to one's immune system as they produce antibodies to fight infections. Speaking to PTI, Rahul Purwar, professor at IIT-Bombay and founder of ImmunoACT and lead author of the study said, "The clinical trials of India's first gene therapy for cancer offer hopes of another chance to live among these patients, that there is one more drug that doctors can try."

'ImmunoACT', or ImmunoAdoptive Cell Therapy Private Limited, is a gene-modified cell therapy company, a spinoff of IIT Bombay. Dr Hasmukh Jain, professor of medical oncology at Tata Memorial Hospital and first author said, "CAR T-cells, just like normal T-cells, persist in the body for a long time.
These cells help to prevent a relapse."

The CAR T-cell therapy is also a cost-effective alternative to that available in the developed world, Purwar added. "We developed it over a period of 11 years, starting with drug design and lab work, which was then translated into animal studies, before progressing to clinical trials," he said.

The injection 'talicabtagene autoleucel' is now approved in India, "available for USD 30,000," which is "less than one-tenth of the price of other approved CD19 CAR T-cell therapy products marketed worldwide", according to the research article.

In a linked commentary article, authors from the University of Pennsylvania in the US -- not involved in the study -- wrote that the approved CAR T-cell products cost USD 3,73,000 to 4,75,000, and clinical care and possible relocation expenses bring the total treatment cost to over USD 1 million.

"Therefore, access to CAR T-cell therapy is an important limitation to the success of this approach in not only high-income countries but particularly in low-income and middle-income countries," the research paper said.

In phase-1 of the India trials, talicabtagene autoleucel was injected into the veins of 14 patients aged 18 years or older having relapsed or refractory B-cell lymphoma. In phase-2 trials, the drug was given to 50 patients aged 15 years and older with relapsed or refractory B-cell leukaemia or B-cell lymphoma.

The typical age of the overall study group was 44 years. Of the 64 patients, 49 were men and 15 women.

While phase-1 trials assess a new drug's safety in 20-100 volunteers, along with how the drug is absorbed and metabolised in the body, phase-2 trials involve 100-300 participants for the testing of the new drug's effectiveness.

Among the 51 patients analysed, "the overall response rate was 73 per cent," according to the paper.

There were two treatment-related deaths, and the most common toxicities were neutropenia (unusually low count of neutrophils), which affected 55 of 57 patients, followed by thrombocytopenia (a low platelet count), which affected 37 of them, the team said.

Anaemia was found to affect 35 patients.

"Talicabtagene autoleucel had a manageable safety profile and induced durable responses in patients with relapsed or refractory B-cell malignancies," according to the research article.

"This therapy addresses an important unmet need for patients with relapsed or refractory B-cell malignancies in India," it said.

Jain said, the findings "give us an opportunity to test the therapy in the earlier settings and in combination with other immunotherapies".

These trials are now underway at the Tata Memorial Centre, he added.

(With PTI inputs)

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