William Earl Janssen

Key Points: This is the first report about the detection of human Tregs specific for minor histocompatibility antigens. We detected, quantified, and cloned mHA-specific Tregs and expanded these potent Tregs in sufficient numbers for use in human transplantation.

A single-institution pilot clinical trial was performed combining nonmyeloablative chemotherapy and the adoptive transfer of tumor-infiltrating lymphocytes with interleukin-2 in patients with metastatic melanoma. Nineteen patients were enrolled with 13 patients (68%) successfully completing treatment. An overall response rate (partial and complete responses) of 26% by intention to treat was achieved with a median follow-up time of 10 months. Of the 13 treated patients, there were 2 complete responses and 3 partial responses (38% response rate among treated patients), along with 4 patients with stable disease ranging from 2+ to 24+months. Three of the 4 patients with stable disease have had disease control without additional therapy, including one at 24+ months. Adoptive therapy with infiltrating lymphocytes is labor intensive but feasible and has a high response rate in treated patients.

Background There is evidence suggesting that sirolimus, in combination with tacrolimus, is active in the prevention of graft-versus-host disease. Sirolimus-based immune suppression may suppress alloreactive T cells, while sparing the survival and function of regulatory T cells. Design and Methods We conducted a randomized trial to compare the impact of sirolimus/tacrolimus against that of methotrexate/tacrolimus on the prevention of graft-versus-host disease and regulatory T-cell reconstitution. Results Seventy-four patients were randomized 1:1 to sirolimus/tacrolimus or methotrexate/tacrolimus, stratified for type of donor (sibling or unrelated) and the patients9 age. The rate of grade II-IV acute graft-versus-host disease at 100 days was 43% (95% CI: 27-59%) in the sirolimus/tacrolimus group and 89% (95% CI: 72-96%) in the methotrexate/tacrolimus group (Pversus-host disease was 24% (95% CI: 7-47%) in the sirolimus/tacrolimus group and 64% (95% CI: 41-79%) in the methotrexate/tacrolimus group (P=0.008). Overall survival and patient-reported quality of life did not differ between the two groups. On days 30 and 90 post-transplant, sirolimus-treated patients had a significantly greater proportion of regulatory T cells among the CD4⁺ cells in the peripheral blood, and isolated regulatory T cells were functional. Conclusions These data demonstrate that sirolimus/tacrolimus prevents grade II-IV acute graft-versus-host disease and moderate-severe chronic graft-versus-host disease more effectively than does methotrexate/tacrolimus, and supports regulatory T-cell reconstitution following allogeneic hematopoietic cell transplantation. Trial registration: (NCT00803010)

We performed a retrospective analysis to evaluate clinical and economic outcomes in patients receiving remobilization therapy after primary mobilization failure. Our primary endpoint was to compare filgrastim plus plerixafor to other regimens in their ability to collect a target cell dose of at least 2 million CD34+ cells/kg (cumulative). Of 96 consecutive patients who failed their primary mobilization therapy and in whom a second mobilization was attempted, remobilization consisted of filgrastim plus plerixafor (n = 38), filgrastim with or without sargramostim (n = 43), or chemotherapy plus filgrastim (n = 15), 84% of filgrastim/plerixafor patients were able to collect at least 2 million CD34+ cells/kg from both mobilizations, compared to 60% of patients mobilized with chemotherapy/filgrastim and 79% of the filgrastim ± sargramostim patients (P = 0.17). However, when combined with cells collected from the first mobilization, 53% of filgrastim/plerixafor patients reached the target of 2 million CD34+ cells in one apheresis, compared to 20% of those receiving chemotherapy/filgrastim and 28% of those receiving filgrastim ± sargramostim (P = 0.02). Resource utilization, mobilization drug costs, clinical care costs, and total costs were significantly different. We conclude that while filgrastim/plerixafor is the most efficient remobilization strategy, those clinical benefits may not translate into lower cost, especially when multiple days of plerixafor administration are required. Am. J. Hematol. 87:673–677, 2012.

Over the immediate past 4 years, our program has collected hematopoietic progenitor cells by apheresis from 48 individuals aged 61 and over (range 61–71 years of age). We have retrospectively analyzed the collection and transplant results associated with employing these donors, and have compared them with 175 donors aged 60 or less who were collected during the same time period. We have found no significant difference in venous access (P=0.208), rate of post-transplant engraftment of neutrophils (P=0.117) and platelets (P=0.692), or in rate and grade of acute GVHD (P=0.806). However, we have found that these older donors have a significantly lower mobilization of CD34+ cells as reflected in lower absolute counts of circulating CD34+ cells pre-apheresis (P=0.016). This, in turn, results in lower CD34+ cell yields in apheresis products (PP=0.095) to collect sufficient CD34+ cells for transplantation. We conclude that it is practical when necessary to employ donors aged 60 and above, as well as safe for both donor and intended recipient. However, concern over reduced CD34+ cell mobilization may be sufficient grounds to seek younger donors when possible.

Local radiotherapy plus intratumoral syngeneic dendritic cell injection can mediate apoptosis/cell death and immunological tumor eradication in murine models. A novel method of coordinated intraprostatic, autologous dendritic cell injection together with radiation therapy was prospectively evaluated in five HLA-A2+ subjects with high-risk, localized prostate cancer, using androgen suppression, 45 Gy external beam radiation therapy in 25 fractions over 5 weeks, dendritic cell injections after fractions 5, 15 and 25 and then interstitial radioactive seed placement. Serial prostate biopsies before and during treatment showed increased apoptotic cells and parenchymal distribution of CD8+ cells. CD8+ T-cell responses to test peptides were assessed using an enzyme-linked immunosorbent spot IFN-γ production assay, demonstrating some prostate cancer-specific protein-derived peptides associated with increased titer. In conclusion, the technique was feasible and well-tolerated and specific immune responses were obs...