Will linking diagnostic tests for lung cancer to treatment deliver the promise of personalised medicine?
November was lung cancer awareness month, a time to assess where we are in cancer treatment and to consider future strategies to help prolong life and avoid the most challenging side effects.
Not long ago, if you were diagnosed with lung cancer, only
standard treatment options – whether surgery, chemotherapy and/or radiation –
were available. Today, medications tailored to your individual genetic makeup
can attack and block mutant cancer cells without harming healthy cells nearby,
with companion diagnostic tests to match mutation to medicine.
Targeted therapies are designed to help the patients who
will most benefit, but for such treatments to be possible there must be a
corresponding diagnostic test to identify the mutations causing the cancer to
replicate on a molecular level, and to inform the treatment plan.
For patients to benefit, their tumours must be analysed, yet
a recent study1 found that more than 25 percent of patients with non-small cell
lung cancer were not being tested for the specific mutations that play a role
in tumour growth and proliferation in up to 60 percent of patients. This was
not due to a lack of tumour tissue available or to the risks associated with
undergoing biopsy.
Those patients now have an alternative, as we have recently
launched a test that can use plasma – taken from a simple blood test – or
tumour tissue to detect 42 mutations in the epidermal growth factor receptor
(EGFR) gene. Now test results are available in about eight hours, a significant
improvement over past tests that could take days to deliver results, and,
unlike biopsies that show the presence of EGFR mutations in a single tumour,
the blood plasma test can detect mutations anywhere in the body. Meaning, if
the original tumour has metastasised, the test will still pick up the EGFR
mutation. Once identified, eligible patients can benefit from existing,
targeted companion treatments.
Roche has been investing in ‘liquid biopsy’ research in
order to remove the barriers that prevent patients from accessing innovative
molecular testing. Obtaining tumour tissue often requires invasive, risky
biopsies and it has its limitations because tumour tissue only presents a
single snapshot in time and is subject to sampling bias resulting from tumour
heterogeneity. Therefore, using a simple blood draw increases access to and
ease of testing. Our cobas EGFR Mutation Test v2 is one of only 10-15 examples
of molecular tests paired to treatment, of which the most widely known is the
test and treatment for the HER2 gene in breast cancer.
Pairing test and treatment is at the forefront of
personalised medicine, especially in oncology, because it helps patients –
through targeted treatment based on their individual molecular profiles, better
side effect profiles and better outcomes – and it offers physicians an
additional way to test for gene mutations, even in patients with advanced
disease. It also benefits payers, who want more value in cost-effective
treatments.
We are currently working to apply the cobas test to monitor
treatment response and progression of the cancer. Clinical trials will be
needed to prove the validity of such applications, and they will need approval
from regulatory agencies, but it is our hope that patients will have their
plasma tested at periodic check-ups to learn if their tumour has progressed,
developed additional drug-resistance mutations or whether the treatment
continues to prevent the tumour from
growing.
This is the future for advanced cancer care; the promise of
personalised medicine – fitting the right treatment to the right patient at the
right dose and the right time – is being fulfilled and the hope for the future
couldn’t be more promising.
1. The study was reported at the reported at the European
Lung Cancer Conference
The author:
Walter Koch is head of global research at Roche Molecular Diagnostics
