It was during my primary schooling days that a classmate was found to be pale and looking not so well. After the summer holidays, the boy was not seen around and we were told he had succumbed to blood cancer or leukaemia. Fast forward to 2010, a young girl in the USA had been battling the same blood cancer (Acute Lymphocytic Leukaemia). All the available options had been explored and it was hitting a dead end. The parents chanced upon an advertisement from the Children’s Hospital of Philadelphia about a new treatment that was being experimented on for blood cancer. The parents decided to take a chance, took their daughter Emily Whitehead immediately and got her enrolled for the trial drug.
The treatment offered then was a new form of immunotherapy to target cancer cells using one’s own cells called lymphocytes fitted with arsenals that go and bind to the cancer cells and kill them. The first night after the drug was injected, a challenge arose. Emily suddenly became unwell. Doctors had a vague clue that Tocilizumab, used to treat rheumatoid arthritis, can douse the acute inflammation reaction that develops following the infusion of the experimental drug (CAR-T). Thanks to this drug, which was used during Covid times in those who got admitted to intensive care, the girl survived and, in June 2012, got discharged from the hospital. Dr Carl June the physician who had been working on this very technology and developed the protocol could successfully salvage Emily from the deathbed. She has since become a celebrity survivor offering hope for thousands like her who are battling incurable blood cancer.
The field of cancer treatment, especially blood and lymph gland-related (lymphoma) cancers has witnessed phenomenal advancements that many types of cancers which were once universally fatal have a ray of hope with better drugs and treatment modalities available. It was in the sixties and seventies that Dr E Donnall Thomas and his research partner Dottie along with their research group at the world-famous Fred Hutchinson Cancer Centre in Seattle, stubbornly pursued stem cell transplantation. There are two ways of using stem cells (the mother cells which produce all the blood components) to deal with cancer. When one’s own stem cells are harvested and injected back, it is called autologous stem cell transplantation and when an unrelated donor’s stem cells are used for the transplantation, which is more technically challenging, it is called allogenic stem cell transplantation. Dr Donnall’s initial attempts were all met with bad failures with people dying but later through further refinements, did the group finally succeed. Around the world today, thousands are getting life-saving stem cell transplantation which has improved the survivability for many incurable blood cancers from zero percent to more than seventy percent in good centres. Further, new advances in cancer treatment have started exploring the options of selectively targeting cancer cells which express unique antigens. This has heralded the newer development of “immunotherapy’” or “cellular therapy”.
The survival of cancer cells in the bone marrow or inside the lymph glands is dependent on a finer interplay of the interaction of cancer cells with the surrounding normal cells.
Cancer cells have the ability to camouflage themselves and avoid getting targeted by the immune attack from one’s own immune system. The landscape of CAR-T treatment is now getting widened to include cancers such as lymphomas and myelomas and the outcomes have been improving drastically.
(The author is a consultant haemato-oncologist with a special interest in stem cell transplantation at Royal Wolverhampton NHS Trust, UK. He can be reached at praveen.kaudlay1@nhs.net)