Dabur OncQuest's novel test known as CML Quest recommended for chronic myeloid leukaemia has proven to be the only clinically available option for oncologists to test drug resistance.
The CML Quest IRMA (Imatinib Resistance Mutation Analysis) is a first-of-its-kind test that is available globally. It was developed after a sequence of research in the Dabur OncQuest in-house laboratory. The test is available only at the centres of Dabur OncQuest pan-India and Nepal since mid-2007. The company has also CML Quest (MRD) the BCR/abl translocation assay by PCR.
CML Quest IRMA is exactly targeted to detect such mutations that enable clinicians to stratify patients as resistant to the targeted drug Imatinib Mesylate.
According to Dr Shyam Agarwal, medical oncologist, Gangaram Hospital, New Delhi, the CML-IRMA is quite a reliable test to identify mutations in ber-abl gene. Some mutations like T315 I are highly resistant to newer drugs like nilotinib and dasatinib. It is an expensive test, but when compared to the newer drugs, this test is cost-effective. This is the only available modality so far. People are working on intracellular levels of imatinib.
"The new mutations develop in chronic phase patients as they take imatinib. These mutations are responsible for resistance to imatinib and patient's condition deteriorates," he added.
Clinicians have widely accepted this test and are recruiting CML patients from all over the country to confirm drug resistance. The test helps to make critical decision on the therapeutic front. Once the BCR/abl Quantification indicates no response to Imatinib mesylate then patients can be quickly examined by CML Quest (IRMA) and switched to higher molecules that are now available in India. The innovation is highly economical as patients save both time and cost on drugs that may not control disease progression.
The test evaluates all major domains of the drug resistant gene that is the locations on gene where drug binds and imparts resistance of varying degrees based on binding sites.
The conclusive inferences are drawn based on the binding regions: if there is a mutation in the catalytic domain at position 315 of the gene it completely renders patient as drug resistance. If the mutations are present in other domain, it is a different clinical situation for the patients and therapeutic choices are made based on clinical picture.
Chronic Myeloid Leukaemia is a type of cancer attributed to change in genetic make up of an individual that forms a chromosome called Philadelphia chromosome OR BCR/abl hybrid gene, formation of that triggers the disease CML. All therapies for CML are directed towards controlling the genetic expression of BCR/abl. This test detects such mutations in the specific region of BCR/abl gene where drug binds and controls gene activity.