Gilead Sciences has bolstered its pipeline of antiviral drugs in recent days through a potentially $320 million-plus licensing deal with DURECT announced today, and a $291 million-plus purchase from Novartis of three preclinical antiviral programs disclosed Friday.
Gilead has licensed exclusive global rights to develop and commercialize a long-acting injectable HIV product using DURECT’s sucrose acetate isobutyrate extended release (SABER®) platform, designed to provide sustained release for long-acting injectable products.
In addition, Gilead gained an exclusive option to license an unspecified number of additional SABER-based treatments for HIV and Hepatitis B Virus (HBV)—as well as exclusive access to SABER for developing HIV and HBV drugs, DURECT said.
“We’ve been working together on this program as a feasibility project, and are now delighted that Gilead has chosen to advance this effort into a formal development program,” DURECT president and CEO James E. Brown, DVM, said in a statement. “We’re pleased to be working on this program with Gilead given their expertise and global leadership in the HIV and HBV fields.”
Under the licensing agreement, Gilead agreed to pay DURECT $25 million upfront, up to an additional $75 million tied to achieving development and regulatory milestones, up to an additional $70 million in sales-based milestones, as well as tiered royalties on product sales.
Gilead also gained the exclusive option to license an unspecified number of additional SABER-based products directed to HIV and HBV, in return for agreeing to pay additional $150 million per product in upfront, development, regulatory, and sales-based milestones—up to $300 million in milestones if one product is developed in each indication—as well as tiered royalties on sales. The companies agreed as well to partner on specified development activities, with Gilead controlling and funding the development programs.
Plunging HCV drug sales
Gilead’s antiviral portfolio includes marketed drugs indicated for HIV, HBV, hepatitis C virus (HCV), as well as influenza. Last year, Gilead’s HIV drugs collectively saw their sales rise 12% compared with 2017, to $14.627 billion from $13.015 billion.
Gilead’s top-selling drug last year was its HIV-1 combination treatment Genvoya® (elvitegravir, cobicistat, emtricitabine, and tenofovir alafenamide), whose sales zoomed nearly 26% over 2017, to $4.624 billion from $3.674 billion. Another HIV-1 drug showing an even greater year-over-year sales gain was Descovy® (emtricitabine and tenofovir alafenamide), which rose 30% to $1.581 billion from $1.218 billion. And a new HIV treatment, Biktarvy® (bictegravir, emtricitabine, and tenofovir alafenamide), achieved blockbuster status in its first year on the market, racking up $1.184 billion in 2018 sales.
However, the company’s HCV drug sales plunged 59% year-over-year, to $3.7 billion from $9.1 billion, reflecting increased competition and the effectiveness of the company’s drugs reducing the number of patients treated.
Leading the way downward was Harvoni® (ledipasvir and sofosbuvir), whose sales near-cratered almost 72%, to $1.222 billion from $4.370 billion in 2017. Also declining significantly was Epclusa® (sofosbuvir and velpatasvir), whose sales fell 44% to $1.966 billion in 2018 from $3.510 billion the previous year.
Neither HIV nor HBV are now represented within DURECT’s pipeline, which is led by the post-operative pain candidate Posimir® (bupivacaine extended-release solution), a nonopioid analgesic under regulatory review for providing three days of continuous local pain relief after surgery.
On Wednesday, DURECT said the FDA acknowledged the company’s response to a Complete Response Letter by the agency rebuffing the company’s NDA for Posimir. The FDA has designated the response as a complete class 2 response to the CRL, and set a target decision date of December 27, 2019.
A boost from Novartis
On Friday, Gilead also boosted its viral pipeline by licensing rights to three preclinical antiviral programs from Novartis, including candidates indicated for human rhinovirus, influenza, and herpes viruses. Gilead agreed to acquire exclusive global rights to develop and commercialize novel small molecules against three undisclosed targets.
In return, Gilead agreed to pay Novartis an undisclosed upfront payment, up to an additional $291 million tied to achieving development and commercial milestones, plus royalties on annual net sales.
The agreements with Novartis and DURECT capped a week of intense deal-making by Gilead under chairman and CEO Daniel O’Day, who took office in March—apparently with pipeline rebuilding in mind. On July 15, Gilead signed a 10-year, up-to-$5.1 billion global R&D collaboration in which Gilead agreed to expand its minority stake in Galapagos, and its role in the companies’ arthritis candidate filgotinib, as well as co-develop the rest of Galapagos’ pipeline.
Galapagos’ pipeline includes six molecules currently in clinical trials, more than 20 preclinical programs, and a drug discovery platform designed to discover and verify novel targets by using disease-related, human primary cell-based assays.
“The collaboration reflects Gilead’s intent to grow our innovation network through diverse and creative partnerships,” O’Day stated at the time, signaling additional partnerships.
Another signal of Gilead overhauling its R&D effort also came last week, when the company disclosed in a July 17 regulatory filing that John G. McHutchison, AO, MD, “decided to step down” as CSO, head of research and development, effective August 2. Gilead said it agreed to pay him a $1.1 million lump-sum payment.
