Chronic myelogenous leukaemia (CML) was long-considered one of the deadliest forms of cancer, capable of striking at any time, causing extreme pain and worse still, affecting both adults and young children. Before the work of two pioneering medical researchers, a diagnosis of CML and subsequent attempts at treatment guaranteed prolonged pain and no certainty of remission. But now with Glivec, a cancer fighting drug with a 98 percent remission rate, CML has lost much of its former bite thanks to American oncologist Brian Druker and Swiss medicinal chemist Jürg Zimmermann.
Inventor(s): Jürg Zimmerman, Brian Druker
Invention: CML Treatment (marketed as Glivec)
Sector: Medical technology
In 1960, researchers identified an abnormally short chromosome in 95% of patients with CML, which they named the Philadelphia chromosome. Understanding the phenomenon of the Philadelphia chromosome was seen as the key to curing CML. After another 13 years of research, it was discovered that the Philadelphia chromosome is the result of two chromosomes swapping DNA.
By the early 1980s, researchers demonstrated that the DNA swap resulted in a fusion protein (the product of two genes or proteins joining together) called BCR-ABL. BCR-ABL causes the overproduction of white blood cells in the body. Where healthy blood contains 4,000 to 10,000 white cells per cubic millimetre, blood from a CML patient contains 10 to 25 times this amount.
In 1990, researchers began looking for BCR-ABL inhibitors and at Novartis, a phamaceutical company based in Switzerland, scientist developed a compound designed to reduce BCR-ABL. Jürg Zimmermann and his team set about improving the compound, eventually creating a potent and specific BCR-ABL inhibitor.
In 1994, Novartis teamed with Brian Druker and set about refining and readying the inhibitor for clinical trials that began in 1999. Today, the compound now known as Glivec is being hailed as something of a wonder drug. Follow-up data show that Glivec therapy helped 98% of patients in chronic-phase CML stabilise their blood counts.
Moreover, in 92 percent of cases, the Philadelphia chromosome was completely disabled, though still present. Patients treated with Glivec followed by a bone marrow transplant, a common course of treatment for CML, experienced a cure rate of 60-80%. Side effects of Glivec tend to be mild and easily manageable, with less than 5% of patients experiencing serious adverse effects.
Thanks to the Zimmermann-Druker partnership, the resources at powerhouses like Novartis and the tireless work of other medical researchers, it seems suddenly possible that a cure for cancer may indeed be found in our lifetime.