FROM THE Journal of Clinical Oncology
One-size-fits-all T cells designed to recognize and mount an immune response against five common viral pathogens may help to reduce the incidence of severe viral infections and treatment-related deaths in patients who have undergone hematopoietic stem cell transplants (HSCT), investigators reported.
Among 37 evaluable patients who had undergone an allogeneic HSCT, a single infusion of banked virus-specific T cells (VSTs) directed against adenovirus, BK virus, cytomegalovirus (CMV), Epstein-Barr virus (EBV), and human herpesvirus 6 (HHV-6) was associated with a 92% cumulative complete or partial response rate, reported Ifigeneia Tzannou, MD, and her colleagues from Baylor College of Medicine in Houston.
“Although a randomized trial will be required to definitively assess the value of banked VSTs, this study strongly suggests that off-the-shelf, multiple-virus–directed VSTs are a safe and effective broad-spectrum approach to treat severe viral infections after HSCT. These VSTs can be rapidly and cost effectively produced in scalable quantities with excellent long-term stability, which facilitates the broad implementation of this therapy,” they wrote in the Journal of Clinical Oncology (2017 Aug 7. doi: 10.1200/JCO.2017.73.0655 ).
Although adoptive transfer of VSTs derived from donor stem cells has been shown to protect patients against viral pathogens, the technique is hampered by costs, complexity, the time-consuming manufacturing process, and the need for seropositive donors, Dr. Tzannou and her colleagues pointed out.
“One way to overcome these limitations and to supply antiviral protection to recipients of allogeneic HSCT would be to prepare and cryopreserve banks of VST lines from healthy seropositive donors, which would be available for immediate use as an off-the-shelf product,” they wrote.
They tested this concept in a phase 2 clinical trial in 38 patients with a total of 45 infections.
A single infusion was associated with cumulative complete and partial responses rates of 71% in 7 patients with adenoviral infections, 100% in 16 patients with BK virus infections, 94% in 17 patients with CMV infections, 100% for 2 patients with EBV infections, and 67% for 3 patients with HHV-6 infections.
Seven of the 38 patients received VSTs for two viral infections, and all patients had viral control after a single infusion. All cases of CMV, adenovirus, and EBV infections were cleared from serum. One patient with HHV-6 encephalitis had complete resolution of encephalitis after one infusion and resolution of hemorrhagic cystitis after a second infusion; 14 patients with BK virus–associated hemorrhagic cystitis had clinical improvement or resolution of disease.
The infusions were delivered safely. After infusion, one patient developed recurrent grade 3 gastrointestinal graft versus host disease (GVHD) after a rapid corticosteroid taper, three patients had recurrent grade 1 or 2 skin GVHD, and two patients had de novo skin GVHD. Of the five cases of skin GVHD, four resolved with the administration of topical treatments and one with the reinstitution of corticosteroids after a taper.
“More widespread and earlier use of this modality could minimize both drug-related and virus-associated complications and thereby decrease treatment-related mortality in recipients of allogeneic HSCT,” the investigators wrote.
The study was supported by the National Heart, Lung, and Blood Institute; Conquer Cancer Foundation; and Dan L. Duncan Comprehensive Cancer Center. Dr. Tzannou disclosed having a consulting or advisory role with ViraCyte, and several coauthors reported financial ties with various companies.