Hylenex Accelerates Time to Peak Blood Concentration for Subcutaneous Morphine

Patients receiving palliative care in hospices, hospitals, and other settings can benefit from a subcutaneous injection of morphine with Hylenex recombinant (hyaluronidase human injection). A Phase 3B clinical trial showed that this formulation, jointly developed by Halozyme Therapeutics, Inc. (San Diego, CA, www.halozyme.com), and Baxter Healthcare (Deerfield, IL, www.baxter.com) accelerated the time to maximal blood levels of morphine by 33% and appeared safe and well-tolerated. Tmax was reduced from 13.8 minutes when injected subcutaneously with the saline placebo, to 9.2 minutes when injected with Hylenex recombinant.

Although morphine is commonly administered intravenously in palliative care, there may be some cases where subcutaneous (sc) administration is preferable, says Richard Yokum, MD, vice president of clinical development and medical affairs at Halozyme. “It can be difficult to find a vein and then to insert a needle into the vein,” he says. “With sc injection, there are an unlimited number of places it can be inserted, and doing so requires less skill.”

Hylenex (rHuPH20) is the recombinant form of the enzyme hyaluronidase and is manufactured through mammalian cell culture using a CHO cell substrate. It has been approved by FDA for use as a spreading agent to increase absorption and dispersion of injectable drugs.

Hyaluronidase increases drug absorption and dispersion by splitting up hyaluronan, a large sugar molecule in the matrix of tissues. “Hyaluronan is a major barrier to the absorption of injected fluids and drugs,” says Yokum. “By splitting up hyaluronan into small fragments, hyaluronidase allows fluids to diffuse rapidly, and thereby be absorbed into the system.”

Yokum explains that the recombinant human product was developed to overcome concerns about allergy and immunologic response from animal proteins, especially in repeat dosing.” It is 99% pure, and eliminates the risk of transmitting diseases, such as bovine spongiform encephalopathy, caused by animal pathogens,” he says.

This Infuse-Morphine study is the second in a series of clinical marketing trials conducted to fully explore the potential of the enzyme. The product is expected to be launched by mid-year.