In Vivo Cell and Gene Therapy Gains Momentum at San Diego Conference

Eli Lilly's $2.4 billion acquisition of Orna Therapeutics highlights growing interest in in vivo approaches to cell and gene therapy.

Published on Feb. 11, 2026

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The cell and gene therapy sector is gathering in San Diego this week for Phacilitate's Advanced Therapies Week, where a recurring theme has been the quickly emerging potential of in vivo approaches to cell and gene therapy. This trend is reflected in recent industry activity, including Eli Lilly's $2.4 billion acquisition of Orna Therapeutics, which uses circular RNA and novel lipid nanoparticles to enable a patient's own body to generate cell therapies.

Why it matters

In vivo cell and gene therapies have 'huge promise [and] heavy investment,' according to industry experts, as they can potentially bypass some of the challenges associated with ex vivo approaches, such as accessibility and the need for immunosuppressive chemotherapy. However, the clinical data for in vivo therapies is still limited, and the investment momentum is outpacing the available evidence.

The details

While ex vivo cell therapy involves extracting, modifying, and then reinfusing patient cells, in vivo approaches deliver the therapeutic payload directly into the patient's body. This can increase accessibility and eliminate the need for lymphodepleting chemotherapy, which can have long-term impacts on the immune system. Additionally, in vivo therapies may face less stringent regulatory requirements around product characterization, as the processes happening within the patient are beyond the manufacturer's control.

  • Eli Lilly announced its $2.4 billion acquisition of Orna Therapeutics on Monday, February 10, 2026.
  • Ultragenyx Pharmaceutical presented new data from two trials of its in vivo AAV9 gene therapy UX111 at the WORLDSymposium 2026 on February 3, 2026.

The players

Susan Nichols

CEO of Propel Bio, a commercialization acceleration partner.

David Ricks

CEO of Eli Lilly.

Francisco Ramírez-Valle

Head of Immunology Research and Early Clinical Development at Eli Lilly.

Victoria Gray

A patient advocate who was the first person with sickle cell disease to be treated with Vertex Pharmaceuticals' and CRISPR Therapeutics' CRISPR-based gene editing treatment Casgevy.

Kristen Hege

Former senior vice president of Early Clinical Development, Hematology/Oncology & Cell Therapy at Bristol Myers Squibb.

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What they’re saying

“We look forward to working with Orna colleagues to potentially unlock an entirely new class of genetic medicines and cell therapies for patients who today have limited or no treatment options.”

— Francisco Ramírez-Valle, Head of Immunology Research and Early Clinical Development at Eli Lilly (Eli Lilly)

“I would love to see the science advance for patients like myself' who are currently required to undergo a conditioning regimen with a chemotherapeutic agent. That was the hardest part for me.”

— Victoria Gray, Patient advocate (BioSpace)

“When we think about in vivo gene therapy, I think a lot of people talk about patient access, cost of goods, but there's more than that. The chemotherapy that's required before the infusion of ex vivo CAR T cells can cause immune suppression that can last for weeks, and we don't really talk about it, but [can also] cause leukemia. Eliminating the need for lymphodepleting chemotherapy, if it pans out with in vivo, could be another real advantage.”

— Kristen Hege, Former senior vice president of Early Clinical Development, Hematology/Oncology & Cell Therapy at Bristol Myers Squibb (BioSpace)

What’s next

Ultragenyx Pharmaceutical plans to address the FDA's concerns about certain aspects of the chemistry, manufacturing, and controls for its in vivo AAV9 gene therapy UX111, which was rejected by the FDA in July 2025.

The takeaway

The growing interest and investment in in vivo cell and gene therapy approaches highlights the potential to overcome some of the key challenges associated with ex vivo therapies, such as accessibility and the need for immunosuppressive chemotherapy. However, the clinical data for in vivo therapies is still limited, and the industry will need to balance the enthusiasm with a careful evaluation of the emerging evidence.