Refined/Accelerated T Cell Therapies for the Treatment of EBV+ Lymphomas

Adoptive T-cell immunotherapies are showing increasing success for the treatment of malignancy. We have previously demonstrated complete responses to Epstein-Barr Virus (EBV) -specific T-cells (EBVSTs) directed against the EBV latent cycle antigens, LMP1 and LMP2 in over 50% of patients with multiply relapsed or refractory EBV+ Hodgkin and non-Hodgkin lymphomas (HL and NHL)(1,2).

Unfortunately, the manufacturing procedures used in this study pose several impediments to the wider applicability of our strategy. These include the use of live virus (EBV) and adenoviral (Ad) vectors and the difficulty of generating EBV-transformed B-cell lines (EBV-LCL) for use as antigen-presenting cells (APCs) from B-lymphoma patients in the rituxan-era.

To simplify manufacture and make our approach more broadly applicable, we have replaced EBV antigens expressed from Ad vectors with overlapping 15mer peptide libraries (pepmixes) spanning LMP 1/2, as well as EBNA1 and BARF1, and used pepmix-pulsed dendritic cells for the first stimulation followed by pepmix-pulsed, autologus activated T cells (aATCs) and irradiated costimulatory cells (HLA-negative K562 cells expressing CD80, CD86, CD83 and 41BB-ligand [K562-CS] as transgenes) for further expansion.

To date, we have generated 15 EBVSTs from 11 patients (5 HL, 1 NK-T lymphoma, 3 lymphoproliferative diseases, 1 EBV+ diffuse large cell B lymphoma, 1 angioimmunoblastic T cell lymphoma) enrolled on an IRB and FDA approved clinical trial NCT01555892. All but one line satisfied the eligibility criteria of the protocol. All EBVSTs were produced in less than one month compared to 3-6 months with our previous protocol (mostly due to the EBV-LCL generation). One patient progressed before the line was ready, but we did not encounter problems in patients pre-treated with rituxan (5/11). At the time of cryopreservation EBVSTs were predominantly central memory (CD45RA-/62L+) (median 80%, range 6-93%), while less than 22% (median 12%, range 4-22%) was effector/effector memory T cells (CD45RA-/62L-). Using a standard γ-INF Elispot, we detected a response to at least 1 antigen in 5/11 patients and against 2 antigens in 2/11 patients. To date, we have treated 5 patients and while it is too early to evaluate clinical efficacy, we have detected increases in the response to the viral antigens in vivo after the infusion. We will continue to enroll, treat and perform the immunological follow up to correlate the immunological follow up results with a clinical response.

This work was supported in parts by grants from the NIH-NCI P50 CA126752 and -NHLB1-N01 HB37163 and the Leukemia & Lymphoma Society SCOR R7016 and a contract from Cell Medica Ltd. 

 

1. Bollard et al.  Blood 2007 Oct 15:110(8):2838-45.

2. Bollard et al. JCO in press