In healthy people, viruses are kept in check by the immune system. But for immunocompromised patients, such as those undergoing transplant procedures, a viral infection is potentially deadly. AlloVir is developing a cell therapy intended to control infections while a patient’s immune system recovers.
Houston-based AlloVir is preparing its lead candidate for late-stage testing and on Wednesday announced $120 million in financing for the research. Fidelity Management and Research Company led the Series B investment round.
When patients receiving a bone marrow transplant to treat a blood disorder or a primary immunodeficiency develop an infection, they have to take antiviral medications. These drugs attack the virus rather than boost the weakened immune system, says Ann Leen, AlloVir’s co-founder and chief scientific officer. She adds that antivirals can cause kidney damage.
AlloVir’s cell therapy is allogeneic, meaning it comes from third-party donors. Leen says the company draws blood from donors whose T cells have been exposed to viruses, which trains the cells to recognize and attack the same viruses in a different person’s body. AlloVir multiplies those cells in a lab to develop its antiviral treatment.
“We grow an immune system outside the body to administer to these patients to control these infections,” says Leen, who is also a professor of pediatrics at the Baylor College of Medicine.
Unlike other T cell therapies, like the two CAR-T products approved for blood cancers, AlloVir uses no genetic engineering to modify the T cells, Leen says. Instead, to find donors whose T cells have been exposed to the right viruses, it uses a screening process similar to that used to identify bone marrow donors. After the T cells multiply in the lab, they are screened again to ensure that they are safe for use in patients, Leen says.
The AlloVir cell therapy is meant to be stored until needed. At the sign of an infection, the therapy can be pulled “off the shelf” and infused into a patient. AlloVir’s lead cell therapy candidate, Viralym-M, has been tested in a 38-patient Phase 2 study. In results released in 2017, the company reported that 92 percent of patients responded to treatment with the therapy, which demonstrated efficacy against five viruses: BK virus, cytomegalovirus, adenovirus, Epstein-Barr virus, and human herpes virus. Two cases of graft-versus-host disease, a complication that can develop after stem cell transplants, were resolved following treatment. Results were published in 2017 in the Journal of Clinical Oncology.
AlloVir was founded at Baylor University’s Center for Cell and Gene Therapy in Houston, where it was initially named ViraCyte. (The name is changing to avoid trademark problems with biotechs ViaCyte and VeraCyte (NASDAQ: VCYT)). As a small biotech in an academic setting, Leen says the firm was looking for larger companies to help with late stage testing. That outreach to ElevateBio, a new Cambridge, MA-based company that aims to manufacture cell and gene therapies for startups. AlloVir will join the facility ElevateBio is constructing in Waltham, MA, but there’s a deeper relationship. ElevateBio CEO David Hallal will also be AlloVir’s CEO. AlloVir is now co-located in Houston and Cambridge.
Hallal says Allovir in 2020 will start a Phase 3 study in bone marrow transplants patients with hemorrhagic cystitis, inflammation and bleeding in the bladder that can be caused by anticancer drugs, radiation therapy, infection, or exposure to dyes or insecticides.
But Hallal added that the data from Viralym-M’s Phase 2 study supports Allovir’s approach to cell therapy and he plans to advance other programs in the company’s pipeline into mid-stage studies in organ transplant patients who have weakened immune systems.
“We view Viralym-M as a pipeline and a platform,” Hallal says.
Other investors in AlloVir’s latest round of funding include Gilead Sciences (NASDAQ: GILD), F2 Ventures, Redmile Group, Invus, EcoR1 Capital, Samsara BioCapital, and Leerink Partners Co-Investment Fund.
Photo by AlloVir