Cord blood NK cells engineered to express IL-15 and a CD19-targeted CAR show long-term persistence and potent antitumor activity

Chimeric antigen receptors (CARs) have been used to redirect the specificity of autologous T cells against leukemia and lymphoma with promising clinical results. Extending this approach to allogeneic T cells is problematic as they carry a significant risk of graft-versus-host disease (GVHD). Natural killer (NK) cells are highly cytotoxic effectors, killing their targets in a non-antigen-specific manner without causing GVHD. Cord blood (CB) offers an attractive, allogeneic, off-the-self source of NK cells for immunotherapy. We transduced CB-derived NK cells with a retroviral vector incorporating the genes for CAR-CD19, IL-15 and inducible caspase-9-based suicide gene (iC9), and demonstrated efficient killing of CD19-expressing cell lines and primary leukemia cells in vitro, with marked prolongation of survival in a xenograft Raji lymphoma murine model. Interleukin-15 (IL-15) production by the transduced CB-NK cells critically improved their function. Moreover, iC9/CAR.19/IL-15 CB-NK cells were readily eliminated upon pharmacologic activation of the iC9 suicide gene. In conclusion, we have developed a novel approach to immunotherapy using engineered CB-derived NK cells, which are easy to produce, exhibit striking efficacy and incorporate safety measures to limit toxicity. This approach should greatly improve the logistics of delivering this therapy to large numbers of patients, a major limitation to current CAR-T-cell therapies.

Allogeneic stem-cell transplantation in patients with cutaneous lymphoma: updated results from a single institution

BACKGROUND

Cutaneous T-cell lymphomas (CTCLs) and its common variants mycosis fungoides (MF) and leukemic Sézary syndrome (SS) are rare extranodal non-Hodgkin's lymphomas. Patients who present with advanced disease and large-cell transformation (LCT) are incurable with standard treatments. In this article, we report the largest single-center experience with allogeneic stem-cell transplantation (SCT) for advanced CTCL.

PATIENTS AND METHODS

This is a prospective case series of 47 CTCL patients who underwent allogeneic SCT after failure of standard therapy between July 2001 and September 2013. The Kaplan-Meier method was used to estimate overall survival (OS) and progression-free survival (PFS) curves. The method of Fine and Gray was used to fit regression models to the same covariates for these cumulative incidence data.

RESULTS

The Kaplan-Meier estimates of OS and PFS at 4 years were 51% and 26%, respectively. There was no statistical difference in the OS in patients who had MF alone, SS, MF with LCT, or SS with LCT. PFS at 4 years was superior in patients who had SS versus those who did not (52.4% versus 9.9%; P = 0.02). The cumulative incidences of grade 2-4 acute graft-versus-host disease (GVHD) and chronic GVHD were 40% and 28%, respectively. The cumulative nonrelapse mortality rate was 16.7% at 2 years.

CONCLUSION

Allogeneic SCT may result in long-term remissions in a subset of patients with advanced CTCL. Although post-SCT relapse rates are high, many patients respond to immunomodulation and achieve durable remissions.

CLINICALTRIALSGOV

NCT00506129.

Bevacizumab/high-dose chemotherapy with autologous stem-cell transplant for poor-risk relapsed or refractory germ-cell tumors

BACKGROUND

High-dose chemotherapy (HDC) using sequential cycles of carboplatin/etoposide is curative for relapsed germ-cell tumors (GCT). However, outcomes of high-risk patients in advanced relapse remain poor. We previously developed a new HDC regimen combining infusional gemcitabine with docetaxel/melphalan/carboplatin (GemDMC), with preliminary high activity in refractory GCT. Given the high vascular endothelial growth factor expression in metastatic GCT and the synergy between bevacizumab and chemotherapy, we studied concurrent bevacizumab and sequential HDC using GemDMC and ifosfamide/carboplatin/etoposide (ICE) in patients with poor-risk relapsed or refractory disease.

PATIENTS AND METHODS

Eligibility criteria included intermediate/high-risk relapse (Beyer Model), serum creatinine ≤ 1.8 mg/dl and adequate pulmonary/cardiac/hepatic function. Patients received sequential HDC cycles with bevacizumab preceding GemDMC (cycle 1) and ICE (cycle 2). The trial was powered to distinguish a target 50% 2-year relapse-free survival (RFS) from an expected 25% 2-year RFS in this population.

RESULTS

We enrolled 43 male patients, median age 30 (20-49) years, with absolute refractory (N = 20), refractory (N = 17) or cisplatin-sensitive (N = 6) disease, after a median 3 (1-5) prior relapses. Disease status right before HDC was unresponsive (N = 24, progressive disease 22, stable disease 2), partial response with positive markers (PRm(+)) (N = 8), PRm(-) (N = 7) or complete response (N = 4). Main toxicities were mucositis and renal. Four patients (three with baseline marginal renal function) died from HDC-related complications. Tumor markers normalized in 85% patients. Resection of residual lesions (N = 13) showed necrosis (N = 4), mature teratoma (N = 2), necrosis/teratoma (N = 3) and viable tumor (N = 4). At median follow-up of 46 (9-84) months, the RFS and overall survival rates are 55.8% and 58.1%, respectively.

CONCLUSIONS

Sequential bevacizumab/GemDMC-bevacizumab/ICE shows encouraging outcomes in heavily pretreated and refractory GCT, exceeding the results expected in this difficult to treat population.

CLINICALTRIALSGOV

NCT00936936.

Outcomes of autologous bone marrow transplantation in non-Hodgkin's lymphoma patients who failed peripheral blood stem cell mobilization

7040

Background: Patients (pts) with relapsed/refractory non-Hodgkin's lymphoma (NHL) who fail to mobilize adequate peripheral blood stem cells (PBSC) often undergo bone marrow (BM) harvest for autologous transplantation. The outcome of these pts is not known. Methods: In this retrospective study (May 1996-September 2006), we identified 36 out of a total of 750 pts with advanced NHL, who failed to collect adequate PBSC and subsequently underwent BM harvest followed by ABMT. Decision to harvest BM was left to the treating clinician. Median age at transplant was 53 years (range 15–73). Twenty of 36 pts (55%) were male. Histology was intermediate grade in 31 (86%) patients and low grade in 5 (14%). Twelve pts (35%) had history of BM involvement with lymphoma. Median number of chemotherapy cycles received prior to mobilization was 3 (range 1–6). At the time of stem cell mobilization 18 (50%) were in complete remission (CR), 13 (37%) were in partial remission (PR) and 5 (13%) had progressive disease (PD). Twenty four (67%) pts underwent chemo-mobilization and 12 (33%) were mobilized with cytokines alone. Results: The median total nucleated cell dose and CD34+ cell dose harvested/kg were 3.72 x 108 (range 0.25–58.0) and 1.6 x 106 (range 0.03–5.8), respectively. After ABMT, 33 of 35 evaluable (94%) pts engrafted neutrophils with median time to ANC 0.5 x 109/L of 23 days (range 8–47). Median time to platelet count 20 x 109/L was 63 days (range 11–375). Two of 35 (6 %) evaluable pts failed to engraft. After ABMT, 25/36 (70%) pts achieved a CR. The incidence of NRM at 100 days was 15%. Sixteen (45%) pts relapsed at a median of 11 months (range 2–59) from ABMT. After a median follow-up of 34 months (range 0.4–100), the 3-year OS and DFS were 47% and 35%, respectively. Causes of death were: disease progression/relapse in 15 (60%), secondary malignancy in 3 (12%), multiorgan failure in 5 (20%), and unknown in 2 (8%). Conclusions: ABMT is feasible in pts who fail to mobilize adequate PBSC, however, these pts have longer time to engraftment. Although the CR rate after transplant is high, the NRM is higher than expected. Non-myeloablative allogeneic transplantation may provide better outcomes with similar toxicity and needs to be further studied.

No significant financial relationships to disclose.

Age at diagnosis does not adversely affect outcome in patients with Hodgkin's Disease (HD) after autologous transplantation

e19507

Background: Age at diagnosis is a poor prognostic factor for overall survival after standard therapy for HD. Whether older age is a prognostic factor for outcome after autologous transplantation is not known. We sought to evaluate the effect of older age at diagnosis on transplant outcome. Patients and Methods: All patients with HD undergoing autologous transplantation with BEAM conditioning (BCNU, Etoposide, Cytarabine, and Melphalan) between January 1996 and December 2007 were included in this study. During these 12 years, 248 patients (103 males) underwent autologous transplantation. Seventy two patients (29%) were older than 40 years of age at the time of initial diagnosis. Median age at transplantation was 31 years (range 11–74). At transplantation, 63 (25%) were in complete remission (CR); 148 (60%) were in partial remission (PR); and 37 (15%) had stable (SD) or progressive disease (PD). Forty-six patients (19%) had received more than 3 courses of chemotherapy prior to transplantation. LDH was elevated in 131 (53%). Peripheral blood stem cells were used as stem cell source in 241 (97%) patients. Results: With a median follow up of 48 months (range, 1–143 months), the 48-month overall (OS) and event-free survival (EFS) were 72% (95% CI; 65%-77%) and 57% (95% CI; 50%-63%), respectively. The cumulative incidence of non-relapse mortality at 1 year was 1.6%. The cumulative incidence of secondary MDS or AML was 8%. In univariate analysis, disease status (p<0.001) and number of prior chemotherapy regimens (p=0.007) were the only factors significantly predicting OS. Disease status was the only factor significant (p<0.01) in a multivariate analysis with a hazard ratio of 2.7 (1.1–6.9) and 9.2 (3.4–25) for patients in PR, and SD/PD respectively (CR reference group). Age at diagnosis was not a significant factor (see table ). Conclusions: High-dose chemotherapy and autologous transplantation abrogate the adverse impact of age at diagnosis in patients with HD.

[Table: see text]

No significant financial relationships to disclose.

Feasibility of allo-SCT after hypomethylating therapy with decitabine for myelodysplastic syndrome

Decitabine is a hypomethylating agent with activity in myelodysplastic syndrome (MDS). It is largely unknown whether treatment with this drug before allo-SCT will increase the toxicity of the preparative regimen or otherwise affect the results of the transplant. We report the outcome of 17 patients with MDS with a median age of 55.5 years (range, 36-66 years) who underwent an allo-SCT (12 siblings, 5 unrelated) after prior therapy with decitabine. Preparative regimens consisted of fludarabine in combination with BU (n=8) or melphalan (n=9). The source of stem cells was marrow in four patients and peripheral blood (PB) in 13 patients. Thirteen patients were in CR within 100 days of transplant. With a median follow-up of 12 months (range, 3-35 months), 11 patients are alive; eight in CR and three with progressive disease. Prior therapy with hypomethylating agents did not increase toxicity and may improve the outcome of allogeneic transplant in MDS and should be evaluated in a prospective trial.