In addition to vaccines, many other drugs currently come in needles. Zosano, among other companies, is working to change that. Its system is an array of titanium microneedles, shaped like arrowheads, that have a dry medicine coating. Once inside the skin, the medicine dissolves away from the needles.
Daddona says they leave only a bit of redness when removed.
Zosano's lead patch candidate is a drug for osteoporosis — teriparatide, a lab-made version of the human parathyroid hormone. Teriparatide is already available for osteoporosis but requires daily needle sticks.
The company recently completed a trial comparing teriparatide-coated microneedles with standard injections, which was published in January in the Journal of Clinical Endocrinology and Metabolism. For six months, 165 women with osteoporosis received, daily, either injections, the microneedle patch with medicine or the patch with a placebo. Researchers found increased bone mineral density in the spines of women who received the drug in either form.
The microneedles appeared to provide more benefit than the single long needle, the scientists reported: When the researchers examined bone density in another site, the hipbone, they found that microneedle delivery increased mineral content while injections did not.
This could be because teriparatide works best when it's given as a brief pulse, Daddona says. With injections, fatty tissue at the injection site slows down the drug's spread. But with microneedles, the medicine reaches the bloodstream faster.
Zosano is in discussions with the Food and Drug Administration to plan a larger trial of the osteoporosis treatment. The company also is developing patches for several other drugs, including erythropoietin for anemia in people with kidney disease.
health@latimes.com
