THURSDAY, Feb. 16 (HealthDay News) -- Remote controls may not be for just appliances anymore. In a new small study, women with severe osteoporosis were implanted with a microchip that releases bone-building drugs at the push of a button, a delivery method that could someday become common for various health conditions.

Roughly 1.5-by-2.5 inches in size, the microchip significantly improved patient compliance with a drug regimen that normally requires painful daily self-injections, study authors said. The clinical trial, conducted on seven osteoporosis patients in Denmark, was the first to test a wirelessly controlled microchip in this capacity.

"It frees patients from the burden of managing their disease on a daily basis," said Robert Farra, co-author of the study and president and chief operating officer of MicroCHIPS Inc., the Waltham, Mass., company that funded and supervised the trial. "I think there will be a class of drugs [for other conditions] that will be very suitable to use the chip for . . . we were very pleased with the results."

The study is published Feb. 16 in the journal Science Translational Medicine, coinciding with its presentation at the American Association for the Advancement of Science annual meeting in Vancouver, Canada.

Along with researchers from MIT, Harvard Medical School and other companies and institutions, Farra implanted the microchip just under the skin near the waistline of the seven women, who ranged from ages 65 to 70 and had been using pre-filled injection pens containing teriparatide (brand name Forteo) for their severe osteoporosis, a bone-thinning disease.

Although a fibrous membrane grew around the device, which was expected, the microchip delivered the drug as effectively as daily injections, the study said. Blood tests done after the 12-month study period indicated rates of bone formation similar to when the women self-injected the drug.

Because daily injections can be psychologically and physically challenging, Farra said, only 25 percent of patients on teriparatide actually finish a typical 24-month regimen. But with the implant -- which delivered 20 timed doses controlled by doctors -- the compliance rate rose to 100 percent.

About 50,000 Americans take the drug each year at a cost of $10,000 to $12,000, which would be comparable to the cost of the microchip and the minor surgery to embed it, he said. The microchip can be implanted under local anesthesia in a doctor's office.

"It not only should offer a better quality of life, we should see improved outcomes because of the compliance boost," Farra said, adding that his company is developing a model that will deliver a year's worth of doses. He said he hopes it is approved by the U.S. Food and Drug Administration and on the market within four years.

Dr. Robert Recker, director of the Osteoporosis Research Center at Creighton University in Omaha, Neb., said he was skeptical that the microchip could keep the Forteo stable at body temperature since the drug is normally refrigerated when contained in injection pens.

However, Farra said that researchers had modified the drug to make this possible, an effort made easier because each dose was also sealed in tiny air- and moisture-proof compartments in the microchip.

The reservoirs pop open on a pre-programmed schedule or via a wireless signal, which can be sent from a doctor's computer or smartphone, Farra said.

"I do not see how this can be done with [a] reservoir, either above or below the skin surface," Recker said. "I think the claim must be corroborated with more studies. They must explain how they preserve the drug at body temperature."

More information

The University of New Hampshire has more about human microchip implantation.