How targeted therapies are boosting outcomes for bone marrow cancer

New Delhi: Patients with chronic myeloid leukaemia (CML) -- a type of cancer of the bone marrow -- are seeing better outcomes with targeted therapies, said experts on Monday.

CML is a slow-growing cancer that affects the bone marrow and blood.

The US National Institute of Health (US) estimates that 1.2 to 1.5 million people worldwide are living with CML. The cancer has seen a notable rise in India, in recent years, with a typical diagnosis occurring in individuals aged 30-40 years.

According to data from Indian cancer registries, CML is the most common type of leukaemia diagnosed in the country. A previous study reported the annual incidence of CML in India to be 0.8 to 2.2 per 100,000 population.

Drugs known as tyrosine kinase inhibitors (TKIs) that target BCR-ABL protein are the standard treatment for CML.

Dr. Tulika Seth, Professor of Haematology at All India Institute of Medical Sciences (AIIMS), told IANS that the discovery of TKIs has revolutionised CML care.

“In recent years, targeted treatments like TKIs have provided relief for patients, especially when resistance to first-line therapies develops. However, maintaining adherence to treatment and regular follow-ups are essential in managing disease progression effectively,” Seth said.

Another is Asciminib, a medicine that specifically targets the ABL myristoyl pocket (STAMP).

These targeted medicines act directly on the BCR-ABL protein, a genetic mutation that drives the growth of cancer cells in CML.

Further, even with these therapies, patients must continue to monitor BCR-ABL levels, Dr. Arijit Nag, Consultant of Clinical Haematology and Bone Marrow Transplant in Tata Medical Center, told IANS.

“In my practice, I have seen targeted therapies have revolutionised in the years and helped the management of CML, this does not mean that CML has ceased to be a chronic illness. Follow-up visits are recommended every three months for patients after commencing treatment,” Nag said.

If CML progresses to advanced stages, resistance can develop due to mutations in the BCR-ABL gene.

“This often requires switching to different TKIs or second-line therapies. Additionally, treatment intolerance -- such as fatigue or gastrointestinal issues -- can impact a patient’s ability to continue therapy,” she noted.

Striking the right balance between managing resistance and minimising intolerance requires individualised treatment plans and close monitoring to ensure the best possible outcomes.

The key is to regularly monitor BCR-ABL levels, especially in advanced stages of CML, as it guides treatment decisions and allows for timely adjustments to therapy, Seth said

According to the European LeukemiaNet (ELN) guidelines, periodic assessments are key to ensuring optimal disease management as the treatment evolves.

It is because BCR-ABL levels will determine whether or not the treatment is working, Nag explained.

Regular testing helps the patient and physician monitor how well the current therapy is working, and change the practice, if required, to best suit the patient's needs.

The experts also called for building a strong support system of adherence, regular monitoring, and family support. This support is crucial, especially as patients progress to later-line therapies.