Shionogi licenses out 3rd-gen HIV asset to ViiV, notches a flop in chronic cough

Japanese pharma Shionogi is looking to build on the success of its GSK- and Pfizer-partnered infectious disease joint venture ViiV Healthcare as it pens a new licensing deal for a long-acting HIV asset.

ViiV, 12% owned by Shionogi, will stump up £20 million ($27 million) in cash to license the experimental asset, known as S-365598, which it sees as a third-generation integrase inhibitor, building on its leading integrase inhibitors dolutegravir and cabotegravir (now Vocabria).

This tweaked med is looking to lessen the need for repeated HIV medication, creating an ultralong-acting regimen at intervals of three months or longer. Everything is still preclinical, with human tests not slated until 2023. That’s when a £15 million payment for the “clinical development milestone” will kick in, with royalties on net sales also on the table.

It’s incredibly early days, but ViiV said preliminary data have shown S-365598 “has a high genetic barrier and a resistance profile that is distinct from that of dolutegravir and cabotegravir.” The idea is that this therapy, should it pass through clinical and regulatory hurdles, could become its next-generation drug for HIV from this decade.

“Our 20-year relationship with Shionogi has been incredibly successful, producing what are arguably two of the most important HIV medicines of the last decade,” said Kimberly Smith, M.D., head of R&D at ViiV.

“Dolutegravir is now taken by 17 million people globally, and cabotegravir has allowed us to develop the first long-acting regimen for treatment. With today’s announcement about the in-licensing of a third integrase inhibitor from Shionogi, we will continue this collaboration and explore the potential of S-365598 to anchor ViiV Healthcare’s pipeline beyond 2030.”

But alongside the deal, which analysts at Jefferies said was a “positive surprise,” Shionogi also noted in a more quiet R&D update that its closely-watched chronic cough hopeful sivopixant (S-600918) failed to meet its primary endpoint, apparently due to a strong placebo effect.

Jefferies said there were glimmers if hope, as a sub-group analysis for the higher dose “gives some room for optimism,” as Shionogi plans to submit an IND for a key late-stage test next year. More details are to be shared at its R&D update on Wednesday, the firm said.

It’s also started domestic phase 2/3 trials of its oral anti-COVID candidate, the oral protease inhibitor S-217622, for the treatment of mild COVID-19 or asymptomatic SARS-CoV-2 infection. The company is planning for local regulatory submission by the end of CY21.