AlloVir conducted a phase 2 clinical study to evaluate its organ transplant therapy with 2 goals in mind. The first one was to check whether or not posoleucel was a safer and more tolerable treatment for transplant patients suffering from BK viremia (BKV), and the other was to check the change in BK viral load in patients who were receiving this treatment. In both instances, the results were compared to that of the placebo.
When it comes to evaluating the safety of the drug, posoleucal was seen to be well tolerated by patients who received even a single dose of the drug. There were also very few instances of infusion reactions, in fact, only 2 percent of the participants showed any signs of it. Compared to this the rate for patients receiving a placebo was 5%. Very rarely was the emergence of donor-specific antibodies observed and the rate of eminence in patients treated with posoleucal was only 7%. While there was the possibility of participants developing cytokine release syndrome and graft versus host disease, no such thing actually manifested in study participants.
There were also no reported instances of death in the study.
When it came to the efficacy analysis of the treatment, it was revealed that at the end of 24 weeks, 39% of the patients that received treatment showed greater reduction in viral load, this is more than double the rate in placebo patients which is only 14%. When dose response in patients was observed it showed that in patients who received a biweekly dose, 50% showed a greater reduction in viral load.
This dropped to 28% when doses were given monthly and in placebo, only 14% of patients showed a greater reduction in viral load. Another notable finding of the data was that the treatment seemed to be most effective when given biweekly and in people with a high initial viral load of ≥10,000 copies/mL, 69% of the study participants that received treatment for a higher viral load showed a reduction and of this 75% that feel in the subgroup of biweekly dosing exhibited similar results.
There were over 60 participants who were enrolled in the study and were given one of the two dosing regimens of posoleucel. Patients were given this on a randomized 1:1:1 ratio. In one group patients were administered the therapy every three weeks and then every two weeks, in the other group, they received therapy every three weeks and then once a month. The last group of patients was those receiving the placebo. The participants enrolled in the study for the treatment of BK viremia in kidney transplant recipients had a viral load of between 350-10,000,000 copies/mL.
While the presence of BKV in the body itself is not harmful, the issue with the presence of the virus in transplant patients is that these patients are generally on long-term immuno-suppressants, which means that the body’s natural immune system is weak. As a result, it is likely that these individuals develop diseases such as BKV-associated nephropathy (BKVAN) and high-level viremia. These two diseases have been linked to causing end-stage renal disease and overall decreased kidney survival. Patients suffering from these inflictions will most likely have to turn back to dialysis.
“BKV is one of the most feared transplant-associated viral infections, due to the lack of available effective antiviral therapies and its profoundly negative impact on transplant outcomes,” said Anil K. Chandraker, principal investigator of the posoleucel BKV treatment study. “The safety profile of posoleucel and its antiviral activity, which is amplified in high viral load patients who have the greatest unmet need, suggest it could potentially offer a transformative treatment option for kidney transplant patients with BK viremia.”
