Successful Human Tests for First Wirelessly
Controlled Drug-Delivery Chip
Two years ago, researchers at the Massachusetts Institute of Technology (MIT) and the MIT-Harvard Center of Cancer Nanotechnology Excellence (CCNE) demonstrated in animal tests that an implantable microdevice could safely and accurately track a tumor marker in a living animal. Now these same investigators report on the first human clinical trials of an implantable microdevice capable of delivering drugs at the direction of an external wireless controller. Though the clinical trial involved a drug used to treat osteoporosis, the device can be used to deliver virtually any drug at programmable intervals over an extended period of time.
Robert Farra of MicroCHIPS, Inc. led the research team that reported its findings in the journal Science Translational Medicine. The device was developed by Michael Cima, Robert Langer, and colleagues at the MIT-Harvard CCNE.
In this study, scientists used the programmable implants to deliver an osteoporosis drug called teriparatide to seven women aged 65 to 70. The study found that the device delivered dosages comparable to injections, and there were no adverse side effects. "Compliance is very important in a lot of drug regimens, and it can be very difficult to get patients to accept a drug regimen where they have to give themselves injections," says Dr. Cima. "This avoids the compliance issue completely, and points to a future where you have fully automated drug regimens."
The human clinical trial began in Denmark in January 2011. Chips were implanted during a 30-minute procedure at a doctor's office using local anesthetic, and remained in the patients for four months. The implants proved safe, and patients reported they often forgot they even had the implant.
Chips used in the study stored 20 doses of teriparatide, individually sealed in tiny reservoirs about the size of a pinprick. The reservoirs are capped with a thin layer of platinum and titanium that melts when a small electrical current is applied, releasing the drug inside. MicroCHIPS is now working on developing implants that can carry hundreds of drug doses per chip. Because the chips are programmable, dosages can be scheduled in advance or triggered remotely by radio communication over a special frequency called Medical Implant Communication Service (MICS). Current versions work over a distance of a few inches, but researchers plan to extend that range.
In the current study, the researchers measured bone formation in osteoporosis patients with the implants and found that it was similar to that seen in patients receiving daily injections of teriparatide. Another notable result was that the dosages given by implant had less variation than those given by injection.
This work is detailed in a paper titled, "First-in-human testing of a wirelessly controlled drug delivery microchip." An abstract of this paper is available at the journal's website.