The Food and Drug Administration (FDA) has granted Orphan Drug designation to posoleucel (Viralym-M, ALVR105) for the treatment of virus-associated hemorrhagic cystitis. 

Virus-associated hemorrhagic cystitis is an inflammatory disease of the bladder that can occur after hematopoietic stem cell transplantation. Posoleucel is an investigational, allogeneic, off-the-shelf, multi-virus specific T-cell therapy that is being evaluated for the treatment and prevention of serious diseases caused by 6 viral pathogens: BK virus and the related polyomavirus JC virus, cytomegalovirus, human herpes virus-6, Epstein Barr virus and adenovirus.

The designation is supported by data from the proof-of-concept phase 2 CHARMS study ( Identifier: NCT04693637) that compared the efficacy and safety of posoleucel to placebo in the prevention of 6 viruses in 58 allogeneic hematopoietic stem cell transplantation patients with at least 1 drug refractory infection. Findings showed that treatment with posoleucel achieved a 93% clinical response and was generally well tolerated.

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The Company is currently investigating the efficacy and safety of posoleucel for the treatment of patients with virus-associated hemorrhagic cystitis following allogeneic hematopoietic stem cell transplantation in an ongoing phase 3 study ( Identifier: NCT04390113).

“This Orphan Drug Designation acknowledges the urgent need for new treatment options for patients who have undergone hematopoietic stem cell transplantation and are at risk for developing viral infections and hemorrhagic cystitis,” said Ercem Atillasoy, MD, Chief Regulatory and Safety Officer, AlloVir. “We look forward to working with the FDA and regulators around the globe as we advance this therapy for patients in need.”

Posoleucel is also being investigated for the preemptive treatment of BK viremia in adult kidney transplant recipients in an ongoing proof-of-concept phase 2 study ( Identifier: NCT04605484).


  1. FDA grants Orphan Drug designation (ODD) to AlloVir’s posoleucel, an allogeneic, off-the-shelf, multi-virus specific T-Cell therapy, for the treatment of virus-associated hemorrhagic cystitis. News release. AlloVir, Inc. Accessed October 4, 2021.
  2. Positive phase 2 Proof-of-concept data for Viralym-M and burden of disease data presented in oral presentations at the 62nd American Society of Hematology Annual Meeting. News release. AlloVir, Inc. December 7, 2020. Accessed October 4, 2021.

This article originally appeared on MPR