GSK's ViiV signs deal to develop longer-acting HIV drugs

The FTSE 100 pharmaceuticals giant said that under the terms of the agreement, ViiV Healthcare, which GSK co-owns with Pfizer and Shionogi, will make an upfront payment of $40m (£28.79m) to Halozyme for the exclusive licence to four HIV small and large molecule targets.

It would also be obliged to make potential future payments of up to $175m in development and commercial milestones per target, subject to the achievement of specified development and commercial milestones, including certain sales targets.

Halozyme would also be entitled to receive mid-single digit royalties on sales of commercialised medicines using the technology.

ViiV explained that the PH20 enzyme breaks down a substance called hyaluronan (HA) that is found under the skin, and acts as a barrier to the flow of fluid.

By breaking down HA locally at the injection site and temporarily removing that barrier, large amounts of fluid could be injected into the subcutaneous space and dispersed.

That would facilitate the “rapid delivery” of large-volume fluids by subcutaneous injection, potentially reducing the treatment burden of injectable drugs and providing optimised treatment options to patients.

The HA is restored under the skin via normal processes within 24 to 48 hours.

Halozyme's technology would provide ViiV Healthcare with more opportunities to develop ultra long-acting medicines with dosing intervals of three months or longer, with its long-acting portfolio and pipeline products.

Plans were underway to initiate the first experiments with the technology by the end of 2021 for investigational, long-acting cabotegravir for the prevention of HIV, which is currently administered every two months.

“Many people living with HIV and those vulnerable to HIV tell us that for a variety of reasons, taking medicine every day is a challenge, and we have listened to them,” said ViiV Healthcare head of research and development, Kimberly Smith.

“We believe long-acting medicines are the future of HIV therapies and will help address these unmet needs.

“Our collaboration with Halozyme will keep us at the forefront of developing additional, innovative new options for HIV treatment and prevention as we work towards reducing the burden of HIV treatment.”

The license would give ViiV exclusive use of Halozyme's proprietary rHuPH20 technology for four specific HIV medicine targets that the company said would expand opportunities for the development of nearly all of its pipeline assets.

Those assets included integrase inhibitors, reverse transcriptase inhibitors limited to nucleoside reverse transcriptase inhibitors (NRTI), and nucleoside reverse transcriptase translocation inhibitors (NRTTIs), capsid inhibitors and broadly neutralising monoclonal antibodies (bNAbs), that bind to the gp120 CD4 binding site.

Halozyme had licensed its technology to 11 pharmaceutical and biotechnology companies for the potential use in oncology, autoimmune disease, rare disease and infectious disease, with products currently approved in oncology and immune deficiency indications.

In addition, Halozyme currently has a cooperative research and development agreement with the National Institute of Allergy and Infectious Diseases' Vaccine Research Center in the United States, which includes a bNAb, N6LS, that ViiV Healthcare licensed from the National Institutes of Health in 2019.

“We are excited to partner with ViiV Healthcare to create new delivery options for innovative medicines for HIV,” said Halozyme president and chief executive officer Helen Torley.

“This collaboration demonstrates the potential value of our technology to facilitate rapid, large volume subcutaneous injections of not only more traditional medicines but also long-acting injectables, including small molecules, which in turn may further extend dosing intervals for people taking medicines for the treatment and prevention of HIV.”

At 0821 BST, shares in GlaxoSmithKline were down 0.58% at 1,406.8p.