28 September 2021 - - UK-based specialist HIV company ViiV Healthcare, which is majority owned by UK-based GlaxoSmithKline (NYSE: GSK), with US-based Pfizer (NYSE: PFE) and Japan-based Shionogi (OTC: SGIOY) as shareholders, have inked an exclusive collaboration and license agreement with Shionogi and Co. Ltd. for S-365598, a third-generation investigational integrase strand transfer inhibitor (INSTI) with potential for use in ultra long-acting HIV regimens (regimens with dosing intervals of three months or longer), the company said.

Under the terms of the agreement, ViiV Healthcare will make an upfront payment of GBP 20m to Shionogi, a GBP 15m payment for the achievement of a clinical development milestone and royalties on net sales.

The royalty levels are aligned with those in Shionogi's existing integrase inhibitor agreements with ViiV Healthcare.

Shionogi will contribute to development costs up to an annual maximum.

Preliminary data has shown that S-365598 has a high genetic barrier and a resistance profile that is distinct from that of dolutegravir and cabotegravir. Its long half-life may support its development as an ultra-long medicine that could be delivered with infrequent dosing of every three months or longer.
Preclinical studies are underway.

ViiV Healthcare and Shionogi intend to initiate first time in human studies with S-365598 by 2023.

Cabenuva is indicated as a complete regimen for the treatment of human immunodeficiency virus type 1 (HIV-1) infection in adults to replace the current antiretroviral regimen in those who are virologically suppressed (HIV-1 RNA less than 50 copies per mL) on a stable antiretroviral regimen with no history of treatment failure and with no known or suspected resistance to either cabotegravir or rilpivirine.

ViiV Healthcare is a global specialist HIV company established in November 2009 by GlaxoSmithKline (LSE: GSK) and Pfizer (NYSE: PFE) dedicated to delivering advances in treatment and care for people living with HIV and for people who are at risk of becoming infected with HIV.

Shionogi joined as a shareholder in October 2012. The company's aim is to take a deeper and broader interest in HIV/AIDS than any company has done before and take a new approach to deliver effective and innovative medicines for HIV treatment and prevention, as well as support communities affected by HIV.