AlloVir’s ambitions, like its share price, have shrunk significantly as the biotech abandons three late-stage trials of its lead asset after realizing none were likely to achieve success.
The Massachusetts-based company had been conducting the trinity of phase 3 trials on posoleucel, an off-the-shelf, multi-virus specific T-cell (VST) therapy, in three indications for allogeneic hematopoietic stem cell transplant patients. Specifically, the company had been testing the therapy to prevent clinically significant infections or diseases from multiple viruses in one trial, while another aimed to treat virus-associated hemorrhagic cystitis (vHC), and the third looked at the treatment of adenovirus.
However, in a triple upset to the company’s plans, analyses by three independent Data Safety Monitoring Boards had each recommended stopping their respective trials for futility. “A review of the data suggested that each study was unlikely to meet its primary endpoint,” the biotech explained in a Dec. 22 release.
Searching for a silver lining, the company pointed out that none of the boards had raised any safety concerns.
"While we are disappointed by the unexpected outcome of these trials, we are encouraged by the apparent safety profile of posoleucel,” AlloVir CEO Diana Brainard, M.D., said in the release. “In light of the DSMB recommendations, we will discontinue the prevention, vHC and AdV phase 3 trials. We will continue to analyze the data from these studies to understand any variables that may have impacted outcomes or any apparent subpopulation benefits.”
Investors seemed far from reassured, however, sending the biotech’s stock plummeting 64% to 83 cents per share in pre-market trading from a Thursday closing price of $2.33.
Such a wide-ranging failure of a company’s lead asset always has serious financial implications, and AlloVir said it will now “review strategic alternatives,” including a merger, company sale or divesting assets. The biotech ended September with $213.3 million on hand, it said.
“With these current results, we will immediately shift our focus to preserve our substantial remaining capital, review our pipeline and assess strategic options,” Brainard added.
Things had been looking up for posoleucel earlier in the year after the therapy posted promising phase 2 results in February. AlloVir’s decision to expand into the solid organ field by assessing the ability of posoleucel to treat a virus called BK viremia in adult kidney transplant recipients seemed to bear fruit when 39% of recipients of posoleucel had a one log or greater reduction in viral load at 24 weeks, compared to 14% of people on placebo.
In its third-quarter earnings report in November, the company promised a “catalyst-rich next 12 months” as the company prepared for “a potential 2025 launch” of posoleucel.
AlloVir has one other clinical-stage asset in the form of ALVR106, an off-the-shelf, multi-virus VST therapy candidate designed to target diseases caused by human metapneumovirus, influenza, parainfluenza virus and respiratory syncytial virus. AlloVir reaffirmed today that it plans to present data from part A of a phase 1b/2a trial of the candidate at a conference in the first quarter of 2024.
Further back in development is ALVR107, another off-the-shelf VST therapy designed to target hepatitis B virus-infected cells.