Halozyme Therapeutics will receive $9 million up front from ViroPharma as part of an exclusive worldwide licensing deal giving the latter rights to use Halozyme’s recombinant human hyaluronidase (rHuPH20) in the development of a subcutaneous formulation of its marketed hereditary angioedema (HAE) drug Cinryze. The license gives ViroPharma exclusive use of the rHupH20 platform for C1 esterase inhibition and for the hereditary angioedema indication, along with three additional orphan indications.
The firms say clinical trials of a subcutaneous formulation of Cinryze for preventing attacks of HAE are projected to start by the end of 2011. Halozyme could receive up to another $74 million in clinical and regulatory milestones, plus a 10% royalty on future sales of Cinryze combined with rHuPH20.
Cinryze is a plasma-derived C1 esterase inhibitor. The intravenously administered formulation is FDA-approved for the routine prophylaxis of attacks in adolescent and adult patients with hereditary angioedema. ViroPharma reported that net sales of the drug reached $57 million in the first quarter of 2011, up 62% on the equivalent period in 2010. The firm projects net sales of the drug in 2011 will reach $245–$260 million.
“Halozyme’s rHuPH20 enzyme may facilitate the subcutaneous administration and absorption of a broad range of pharmaceuticals and biologics, including plasma-derived proteins such as Cinryze,” remarks Gregory I. Frost, Ph.D., Halozyme’s president and CEO.
rHuPH20 is a human synthetic version of hyaluronidase designed to temporarily degrade the matrix filler hyaluronan and facilitate the penetration and diffusion of drugs or other fluids injected under the skin. The technology forms the basis of Halozyme’s FDA-approved Hylenex® platform for generic small molecules and fluids, and for Enhanze technology for proprietary small and large molecules.
The firm is exploiting its technologies both for the development of an in-house pipeline of PH20-formulated drugs and also through partnerships with the industry. Halozyme’s most advanced in-house clinical program is applying the PH20 technology to currently marketed mealtime insulin products. Just last month the firm announced positive results from a study in type 1 diabetes patients evaluating Aspart-PH20, a formulation of rHuPH20 with NovoLog®, delivered using a subcutaneous pump.
Halozyme is separately developing PEGylated-rHuPH20, or PEGPH20, as a new molecular entity for the systemic treatment of tumors rich in hyaluronan; dose-ranging Phase I evaluation is ongoing. The firm’s preclinical Chemophase bladder cancer program, currently on hold due to financial restraints, aims to combine PH20 with mitomycin C for direct administration into the bladder after the transurethral resection of bladder tumors. A separate preclinical program is evaluating two collagen-degrading recombinant enzymes, HTI-501 and MMP1ts, for potential utility in both medical and aesthetic dermatology applications.
Halozyme’s partnered programs, with Roche and Baxter, include clinical-stage products in the oncology, anti-inflammatory, and immunology fields.