The double-blinded clinical study compared recombinant human hyaluronidase (rHuPH20) to a saline control in 100 healthy human volunteers. These volunteers were injected intradermally with rHuPH20 in one forearm and saline control in the other forearm, and evaluated for allergic responses and injection site side effects.
None of the 100 subjects had evidence of allergenicity. With regard to side effects, 28 of the 100 subjects experienced discomfort (e.g., stinging, burning) at the site of saline injection, whereas significantly fewer, 3 of the 100 subjects, experienced such side effects at the site of rHuPH20 injection.
“These clinical data show that rHuPH20 is well-tolerated by healthy human volunteers,” said Richard Yocum, Halozyme’s vice president of clinical development and medical affairs. “The lack of allergic response to rHuPH20 is important, as the most frequently reported adverse experiences with currently available, animal-derived hyaluronidase products are local injection site reactions. The significant reduction in injection site discomfort is consistent with the rapid-onset mechanism of action of this enzyme.”
Halozyme’s rHuPH20 is a highly purified, recombinant form of the naturally occurring human enzyme and is being investigated for its ability to break down hyaluronan (HA, also known as hyaluronic acid), the space-filling “gel”-like substance that is a major component of tissues throughout the body. Hyaluronidase that is injected in the skin or in the muscle can temporarily digest the HA gel to enhance the penetration and diffusion of other injected drugs or fluids.
Halozyme’s recombinant human enzymes may replace current animal slaughterhouse-derived enzymes that carry potential risks of animal pathogen transmission and immunogenicity. The versatility of the first enzyme, rHuPH20, enables Halozyme to develop the product as a medical device, drug enhancement agent, and therapeutic biologic.