Like transdermal patches, hydrogel implants offer automatic delivery, advantageous for those with chronic diseases, or for those with Alzheimer’s or arthritis or psychotic disorders who don’t remember to take their medication.
Hydrogels are a type of plastic — or polymer — with the advantages of both liquids and solids. They can function in a gel state but, like liquids, transport large molecules. They can have controlled thicknesses, and they can control distribution through filters and screens.
Like patches, hydrogel implants can be a silver lining for pharma companies with drugs that are about to go “off patent” and be sold as generic products. Put that drug in a hydrogel implant — using a material similar to that found in contact lenses — and not only does it represent a new revenue stream, but it has real advantages to the patient.
For instance, the previous treatment for prostate cancer involved painful monthly or quarterly injections in the stomach. In 2003 Valera Pharmaceuticals (formerly Hydro Med Sciences) began to market Vantas, a hydrogel polymer implant for prostate cancer.
Vantas, a 12-month hormone suppression therapy for advanced prostate cancer, contains the testosterone-reducing medication called histrelin. Vantas is a small, flexible cylinder that is placed under the skin of the upper inner arm. It remains in the arm to release histrelin continuously for a whole year. The histrelin reduces PSA — a prostate-specific antigen — a blood chemical associated with prostate cancer.
Valera is ready to begin Phase I/II clinical trials for a new narcotic addiction treatment that involves implanting a device under the skin of those addicted to pain-relieving drugs. The drug used, naltrexone, blocks euphoria-inducing chemicals produced by heroin and prescription pain killers such as morphine, hydrocodone, and oxycodone. It is approved for oral medication.
Valera has also filed a new drug application with the Food and Drug Administration to treat central precocious puberty, the premature development of secondary sexual characteristics in young children. Left untreated, the disorder can stunt a child’s growth.
The drug, Supprelin-LA, provides suppression of normal hormone production. The synthetic hormone used, histrelin, is approved for daily injection, but the new drug is a 12-month implant. The hydrogel technology dates back to the 1960s, when more than 100 scientists at Prague’s Academy of Sciences were laboring on polymer research projects. In the 1990s, so many Czech scientists moved to the Route 1 corridor, that it was dubbed “Hydrogel Valley.”
Valera Pharmaceuticals, 7 and 8 Clarke Drive, Cedar Brook Corporate Center, Cranbury 08512; 609-409-9010; fax, 609-409-1650. David Tierney, CEO. www.valerapharma.com