Implantable device could allow for better-targeted cancer treatment
While there are a large number of approved cancer treatments, identifying which drugs are best suited to individual patients is extremely difficult for doctors. A team of MIT researchers has developed a small, implantable device that aims to change this by allowing scientists to measure the effectiveness of different drugs, on a patient-by-patient basis.
When testing the effectiveness of a drug, a common technique is to extract tumor cells from the patient and use them to test a drug in a lab environment. The problem with this method is that the conditions under which the drug is acting are altered, with the conditions of the lab failing to accurately mimic those found inside the patient's body. To combat this, the MIT research team decided to turn the method on its head.
"The approach that we thought would be good to try is to essentially put the lab into the patient," said Oliver Jonas, a postdoc at MIT’s Koch Institute for Integrative Cancer Research. "It’s safe and you can do all of your sensitivity testing in the native microenvironment."
The device that the team engineered is around the size of a grain of rice, containing tiny reservoirs that can carry up to 30 different drugs. Constructed from a stiff, crystalline polymer, it's implanted into a patient via a biopsy needle.
Once in place, the device releases its various drug payloads, with the treatments seeping just 200 to 300 microns into the tumor without overlapping with one another. After 24 hours, the implant is removed from the patient along with a sample of the tumor surrounding it. The sample is then sliced into segments, separating the different drug treatments, before being analyzed using antibodies that can detect cell death.
The team tested the device on laboratory mice carrying breast, prostate and melanoma tumors that have known sensitivities to certain drugs. The results of the implant method matched up with existing knowledge of individual drug effectiveness.
Similarly, when testing the implant on triple negative breast cancer, the implant was able to identify the five drugs known to be most effective in combating the aggressive tumors.
In light of the positive results of the study, it's thought that the new method could help identify the best treatment options for individual patients. Furthermore, while the research focused on comparing the effectiveness of individual drugs, the implant could also be used to test varying combinations of drugs against each other.
It could also potentially be used as an effective method of testing experimental cancer drugs, allowing researchers to observe the effectiveness of different variants of a treatment.
The team is continuing its research, and is now working to make it possible to read the results of the implant while it's still inside the patient. A clinical trial will launch in 2016, focusing on breast cancer patients.
A paper describing the device was published on April 22 in the online edition of the journal Science Translational Medicine.