Gene Writing Pioneers Target HIV with Gates Foundation Backing

SOMERVILLE, Mass. – March 23, 2026 – In the relentless global fight against Human Immunodeficiency Virus (HIV), a new chapter is being written—not just in books, but potentially within the human genome itself. Tessera Therapeutics, a biotechnology firm at the vanguard of genetic medicine, announced today it has received a grant from the Bill & Melinda Gates Foundation. The funding is aimed at exploring a revolutionary approach that could lead to a scalable, single-shot cure for the virus that affects nearly 40 million people worldwide.

The grant will fuel early-stage research into Tessera’s proprietary “Gene Writing” platform, a technology designed to make precise edits to DNA directly inside the human body. This in vivo approach marks a significant departure from many current gene therapy strategies and holds the potential to overcome some of the most persistent barriers to an HIV cure.

“HIV continues to affect millions of people worldwide,” said Michael Holmes, Ph.D., Chief Scientific Officer of Tessera Therapeutics, in a statement. “Our Gene Writing platform can potentially enable new ways to engineer immune cells directly in the body. We look forward to advancing this research and identifying promising paths toward a potential single shot treatment for HIV.”

A New Tool in the Genetic Arsenal

At the heart of this ambitious project is Tessera's Gene Writing technology, a novel system that aims to go beyond the capabilities of first-generation gene editing tools like CRISPR-Cas9. While CRISPR is often described as a pair of “molecular scissors” that cuts DNA to disable or remove faulty genes, Gene Writing operates more like a sophisticated word processor for the genome.

Inspired by naturally occurring mobile genetic elements, or “jumping genes,” the technology uses a process called Target Primed Reverse Transcription (TPRT). Instead of creating a potentially risky double-strand break in the DNA, Gene Writing nicks a single strand and uses an RNA or DNA template to “write” new genetic information into the target site. This allows for a wide range of edits, from correcting single-letter misspellings in the genetic code to inserting entire therapeutic genes.

For HIV, Tessera plans to evaluate several powerful strategies:

• Disrupting viral entry: Modifying the genes for cellular receptors like CCR5, which HIV uses as a doorway to infect immune cells.
• Arming immune cells: Introducing genes that produce antiviral proteins, effectively turning T-cells into factories for HIV-inhibiting molecules.
• On-demand antibodies: Engineering immune cells to produce broadly neutralizing antibodies (bNAbs), a potent type of antibody that can fend off numerous HIV strains.
• Creating cell therapies in vivo: Generating engineered immune cells, such as CAR-T cells, that can hunt down and destroy cells harboring the virus—all without having to remove and reinfuse them.

This versatility is key to tackling a virus as complex and evasive as HIV.

The Quest for a Scalable Cure

For decades, the holy grail of HIV research has been a cure. While modern antiretroviral therapy (ART) has transformed HIV from a death sentence into a manageable chronic condition, it is not a cure. The virus masterfully hides in a latent state within cellular reservoirs, ready to rebound if daily medication is ever stopped. This necessitates lifelong treatment, which carries a heavy burden of cost, side effects, and social stigma.

The most significant promise of Tessera's approach lies in its potential for scalability. Current cell and gene therapies, particularly those developed for cancer, often rely on ex vivo manufacturing. This involves drawing a patient's cells, shipping them to a specialized facility for engineering, and then infusing them back into the patient—a process that is logistically complex, astronomically expensive, and ill-suited for global deployment.

By designing a therapy that works in vivo, delivered in a single shot via a lipid nanoparticle, Tessera aims to bypass this bottleneck entirely. A scalable, off-the-shelf treatment could be distributed and administered far more easily, making it a viable option not just in high-income nations, but in the low- and middle-income countries of sub-Saharan Africa and Asia that bear the brunt of the HIV epidemic.

A Strategic Bet on Transformative Technology

The involvement of the Gates Foundation is more than just a financial endorsement; it is a strategic validation of Tessera's platform and its potential for global impact. The foundation has long been a heavyweight in the fight against HIV, and in recent years, it has made a concerted effort to ensure that cutting-edge genetic medicines are developed with global access and affordability in mind from the very beginning.

This new grant builds upon a previous investment the foundation made in Tessera to develop a similar in vivo Gene Writing therapy for sickle cell disease, another major global health challenge. This pattern suggests a deep confidence in the technology's potential to deliver on the promise of one-time, curative treatments for diseases that have plagued humanity for generations.

The foundation's strategy explicitly targets the development of therapies that can be delivered in low-resource settings, a goal that aligns perfectly with Tessera’s vision of a single-shot in vivo cure.

The Long Road from Hope to Reality

Despite the immense promise, it is crucial to temper excitement with a dose of reality. This research is in its earliest stages. The path from a promising concept in the lab to a safe, effective, and globally accessible medicine is long, arduous, and fraught with uncertainty.

In vivo gene therapies face a high bar for regulatory approval. Scientists and regulators at agencies like the U.S. Food and Drug Administration (FDA) will demand extensive data proving not only that the therapy works, but that it is safe for long-term use. Key concerns include off-target effects, where the Gene Writer might make unintended edits, and immunogenicity, the risk that the body could mount an immune response against the therapeutic components.

Furthermore, the ethical implications of deploying a permanent genetic therapy on a global scale are profound. Ensuring equitable access, obtaining meaningful informed consent across diverse cultures, and managing the societal impacts of such a powerful technology will require careful and continuous dialogue among scientists, ethicists, policymakers, and the public.

The journey to end HIV has been a marathon, not a sprint. While Tessera's Gene Writing technology offers a tantalizing glimpse of a finish line, the road ahead is filled with scientific and logistical hurdles that must be overcome before this innovative approach can rewrite the future for millions living with the virus.