This is a Phase 2/3, multicenter, randomized, double-blind, placebo controlled trial comparing posoleucel to placebo for the prevention of infection or disease due to AdV, BKV, CMV, EBV, HHV-6, or JCV in high-risk adult and pediatric patients after allogeneic HCT.
There are 2 parts to the study, an open label Phase 2 cohort described in this posting, and a randomized, placebo controlled Phase 3 cohort described in NCT05305040. In the Phase 2 part, 25 to 35 eligible allogeneic HCT recipients will be enrolled and will receive 7 doses of posoleucel over 12 weeks, followed by a 14 week follow-up period.
Key Inclusion Criteria
* ≥1 year of age at the day of screening visit.
* Either no evidence of viral infection or viremia, or asymptomatic, viral infection with 3 or fewer viruses of interest at time of screening
* Within 15 and 42 days of receiving a first allogeneic HCT and have demonstrated clinical engraftment
* Meet one or more of the following criteria at the time of randomization:
* Related (sibling) donor with at least one mismatch at one of these HLA-gene loci: HLA-A, -B or -DR
* Haploidentical donor
* Unrelated donor with at least one mismatch at one of these HLA-gene loci: HLA-A, -B, -C, or -DR
* Use of umbilical cord blood as stem cell source
* Ex vivo graft manipulation resulting in T cell depletion
* Lymphocyte Count \<180/mm3 and/or cluster of differentiation 4 (CD4) Count \<50/mm3
Key Exclusion Criteria:
* History of AdV, BKV, CMV, EBV, HHV-6, and/or JCV end-organ disease within 6 months prior to randomization
* Evidence of active Grade \>2 acute GVHD
* Presence of non-minor uncontrolled or progressive bacterial, viral or fungal infections
* Known history or current (suspected) diagnosis of CRS requiring treatment associated with the administration of peptides, proteins, and/or antibodies
* Ongoing therapy with high-dose systemic corticosteroids (ie, prednisone equivalent dose \>0.5 mg/kg/day) within 24 hours prior to dosing
* Relapse of primary malignancy other than minimal residual disease
Note: Other protocol defined Inclusion/Exclusion criteria may apply.
