Calibr, the drug discovery and development division of Scripps Research, announced Gilead Sciences, Inc. (Nasdaq: GILD) has exercised its option to exclusively license the research institute’s investigational nucleoside reverse transcriptase translocation inhibitor (NRTTI) prodrug.


Source: CDC/ C. Goldsmith, P. Feorino, E. L. Palmer, W. R. McManus

Scanning electron microscopic (SEM) image of human immunodeficiency virus-1 (HIV-1) virions seen as small round bumps, in the process of budding from a cultured lymphocyte.

The NRTTI prodrug, designated GS-1614, is a development candidate resulting from a collaboration between Scripps Research and Gilead aimed at advancing a best-in-class long-acting HIV regimen.

Calibr designed and optimized GS-1614 with support from the Bill & Melinda Gates Foundation. Gilead has initiated a Phase 1 clinical study of GS-1614 in healthy volunteers to determine the optimal dose, safety profile and frequency of administration.

Gilead exercised its option with Calibr in connection with Gilead’s collaboration with Merck & Co., Inc. toward the development and commercialization of a long-acting injectable regimen for HIV.  Pursuant to that collaboration, Gilead and Merck will evaluate GS-1614, a prodrug of Merck’s islatravir, for use in combination with Gilead’s novel capsid inhibitor, lenacapavir.

Global epidemic

HIV remains a global epidemic despite continuous scientific discoveries and person-centric advances in HIV care. To help overcome the HIV epidemic, long-acting options are being developed to help address the differentiated needs and preferences of the wide range of individuals and communities affected by the virus.

Research and innovation that focuses on helping to meet the diverse needs of those affected by HIV will have the most significant public health impact by expanding options for all people and communities impacted by a major global public health issue.

Vital expansion

“We are excited to collaborate with Gilead on this program,” says Peter Schultz, PhD, President and CEO of Scripps Research and Calibr.

“If successful, this program will mark a vital expansion of HIV options. A once every three month or longer injectable like that being investigated by Gilead and Merck could potentially improve health outcomes via greater adherence and reduced emotional burden and stigma for people with HIV.  This milestone also represents an important step forward in our mission of translating scientific insights and discoveries into clinical trials to create impact for patients and value for the institute that supports further drug discovery and development efforts.”

Under the collaboration, Calibr receives upfront and near-term milestone payments and will be eligible for development milestones and royalties. Gilead holds an exclusive, worldwide license to GS-1614. Additionally, under the collaboration, GS-1614 potentially can be explored as a pre-exposure prophylaxis (PrEP) option in the future.

As an investigational compound, GS-1614 has not yet been determined safe or efficacious in people with HIV. The ongoing Phase 1a trial aims to establish its safety and long-acting profile in