Weak link of common leukaemia identified

A new study says that that gene mutation may have a great role to play in acute myeloid leukaemia - one of the most common forms of human leukaemia- indicating a promising new target for the condition.

The study conducted at the University of California, San Francisco (UCSF) Helen Diller Family Comprehensive Cancer Center and spearheaded by physician-scientists, authenticates certain activating mutations in the FLT3 gene as targets for acute myeloid leukemia therapy. These findings can pave way for the development of a drug that can combat this disease.

"These mutations are critically important for the survival of leukemia cells that harbor them," Neil Shah, MD, PhD, who headedthe research, and is co-leader of the Hematopoietic Malignancies Program at the Helen Diller Family Comprehensive Cancer Center at UCSF and the Edward S. Ageno Distinguished Professor of Hematology/Oncology has been quoted as saying.

"Our results also identify drug-resistant mutations in FLT3 that represent high-value targets for future drug development, and will hopefully rekindle interest in developing potent FLT3 inhibitors for the treatment of acute myeloid leukaemia," he explained.

The new study also reflects on why some older drugs developed to treat acute myeloid leukemia by targeting FTL3 have formerly could not do well in clinical trials. These drugs did not have lack of precision but of power-the drugs were aimed at the right target needed to stop the cancer, but probably they did not hit the target as hard as required.

In the future Patients can be served by therapies consisting combinations of multiple, more potent drugs that can overpower all drug-resistant forms of FLT3, said Shah, head of the lab that is working to identify such compounds and bring them to the clinic as fast as possible.

Acute myeloid leukemia is a condition in which the precursors of our own blood cells become corrupted by mutations in their DNA. These mutant precursors becomes unable to produce several critical components of blood: white cells, which fight infections; red cells, essential to carry the blood's oxygen supply; and platelets, which clog vessels in times of injuries checking the loss of blood.

On the other hand, the mutant precursors give rise to leukemia cells, that accumulate in the bone marrow and bloodstream, crowding out the healthy blood components, and also results in life-threatening infections, anemia, and bleeding.

In the recent decades, the five-year survival for acute myeloid leukemia has not changed for better, even when improved better diagnostic tests, imaging techniques and treatments have reduced the mortality rate for other forms of cancer.

Shah and his team of researchers conducted this study on eight leukemia patients on whom a clinical trial involving a compound known as AC220, the first clinically-active FLT3 inhibitor was conducted. All these patients relapsed after first achieving deep remissions with AC220.

In coordination with Pacific Biosciences, a Menlo Park, Calif. company, a new sequencing technology was put into practice to recognize drug-resistant mutations to more sensitively and precisely detect. The team showed that in all eight cases, one or more of these mutations evolved at the time AC220-resistant disease developed.

The team of researchers is now looking for compounds that can particularly target these mutated, AC220-resistant forms of FTL3, and have found out several promising candidates, one of which is currently being examined in a clinical trial at UCSF by Catherine Smith MD, who works in Shah's laboratory and also the first author of the study.

The journal Nature has published these findings in this week edition.

--with inputs from ANI