Because each cancer arises from a unique set of mutations, the sensitivities of different tumours to different drugs is highly individualised and unpredictable. Drug sensitivities between tumours found in the same organ vary, and the most effective drug for treating a cancer of the ovary, for example, may in fact turn out to be one licensed for use in lung cancer. The current challenge is therefore choosing which drugs are best for each patient.
If we could discover a way of finding the best drug for each patient, outcomes would be dramatically improved even without the development of new drugs; by using what we have now more effectively.
It is this matching of drugs to patients that Imagen Therapeutics is striving for.
Imagen Therapeutics performs a functional test, which is often termed a phenotypic screening approach. The approach is concerned with examining the overall “functioning” of the cell under certain scenarios – in this case what they do when exposed to different drugs. We take a sample of the patient’s cancer and expose the cells to drugs for 72 hours and measure their cytotoxic effects. This focus determines what makes cancer cells die.
This approach provides benefits:
- ACCURATE – direct measure of cell death
- FAST – results available within 2 weeks
- COMPREHENSIVE – routinely produce detailed information on up to 56 different chemotherapies
- PERSONALISED – tested on samples derived directly from your patient
- Results tell the treating oncologists which drugs are killing the cancer cells
Other assay measure MTT and ATP, neither of which measure cell death directly but an average metabolic reading that is assumed to be proportional to the number of cells present. In these types of assay, agents that suppress cellular metabolism or cell division, without inducing cell death give a false positive reading.
In contrast, Imagen Therapeutics’ predictRx provides a direct measure, meaning that it can separately determine whether a compound’s action induces cell death or inhibits cell growth. This is possible because we directly image the cells, meaning that we can delineate cytotoxic from cytotrophic effects.
Because of the technology we use, Imagen Therapeutics is able to work with small amounts of fresh tissue. This means that we can test many drugs at different doses, without having to culture cells to produce greater quantities – which may lead to “phenotypic drift”. This is a phenomenon whereby the underlying biological characteristics vary over successive generations.
Between 2013 and 2015, Imagen Therapetuics processed many cancer samples using our system.
In ovarian cancer, we compared clinical response rates of patients to their next cycle of chemotherapy with the chemosensitivities we predicted. (Note: this was a match-up exercise to test the predictive value of our test; we did not influence treatment). Of the 28 patients for whom we have had clinical follow-up data, we correctly predicted the response to the next chemotherapy they received in all but one case.
Of the 28 patients, 21 patients did NOT respond to their next cycle of chemotherapy, and we predicted that this would be the case in all 21 patients. Eight patients DID respond to their next cycle. We predicted that this would be the case in seven of the eight cases.
Our clinical partners are currently auditing this preliminary data prior to publication.
During this auditing process, we found that in one patient:
- We predicted that she would not respond to a paclitaxel, carboplatin combination. As expected, her Ca125 levels and CT scan data indicated that the tumour had increased in size (progressive disease) during this treatment.
- Later, she was switched to carbocaelyx (a doxorubicin, carboplatin combination). Our screening data had clearly indicated that she would respond to doxorubicin, and, as expected, this second line treatment was very effective against her cancer.
These data mean that Imagen Therapeutics correctly identified not only drugs that would not work for this patient but also predicted a drug that turned out to be effective.
Imagen Therapeutics remains committed to helping improve cancer treatment outcomes for all cancer sufferers.
If you would like more information about our company or feel you can support our experimental aims then please do not hesitate to get in contact.