Roche and Trimeris, Inc. have announced that they will no longer pursue government approval to market a needle-free injection device for use with their entry inhibitor, Fuzeon (enfuvirtide).

Fuzeon, an antiretroviral drug that must be given by injection with a syringe under the skin, is typically used by people who are heavily treatment experienced. Pain, swelling, bumps and skin hardening at the site of the injections are the primary side effects of Fuzeon, occurring in up to 98 percent of people who use it. Fuzeon’s makers had hoped that a needle-free device, called the Biojector 2000 (B2000), would result in fewer such reactions. Although studies of the device have found that its use did result in fewer of the kind of injection-site reactions seen with syringes, the B2000 did cause bruising and nerve pain lasting up to six months in some people who used it. Because of this, the Food and Drug Administration (FDA) had twice asked Roche and Trimeris for additional safety data before approving the B2000 for use with Fuzeon.

The problems with the B2000 injector and the resulting delays at the FDA have led Roche and Trimeris to conclude that “[they] don’t believe it’s the ideal alternative delivery option for all treatment-experienced patients.”

The companies say that they will continue to evaluate other possible delivery devices and that people who are currently using the B2000 through a clinical trial or another program may continue to do so provided that they follow instructions included in Fuzeon’s safety label about the injector.