Don Morris

A phase I trial of intratumoral administration of reovirus in patients with histologically confirmed recurrent malignant gliomas.

Reovirus is an oncolytic virus with activity in in vivo models of malignant gliomas (MGs). The primary aims were to determine the dose-limiting toxicity (DLT) and maximum tolerated dose (MTD) of intratumoral administration of reovirus in patients with recurrent MGs. Response, survival, and time to progression (TTP) were secondary aims. Patients were adults, had Karnofsky Performance score > or = 60, received prior radiotherapy with or without chemotherapy, and had up to the third recurrence of MG. Reovirus was administered intratumorally stereotactically at 1 x 10(7), 1 x 10(8), or 1 x 10(9) tissue culture infectious dose 50 (TCID50) in a volume of 0.9 ml. Twelve patients were treated at three dose levels (3, 6, and 3 patients, respectively). Seven were men, median Karnofsky Performance score was 80, and median age was 53.5 years. There were no grade III or IV adverse events (AEs) definitely or probably related to treatment. Ten patients had tumor progression, one had stabilization, and one was not evaluable for response. Median survival was 21 weeks (range, 6-234), and one is alive 54 months after treatment. Median TTP was 4.3 weeks (range, 2.6-39). An MTD was not reached. The intratumoral administration of the genetically unmodified reovirus was well tolerated using these doses and schedule, in patients with recurrent MG.

High-dose thiotepa, busulfan, cyclophosphamide and ASCT without whole-brain radiotherapy for poor prognosis primary CNS lymphoma

Summary:Treatment of primary central nervous system lymphoma (PCNSL) with combined high-dose methotrexate (HD-MTX)-based chemotherapy and whole-brain radiotherapy (WBRT) is associated with severe neurotoxicity, but high relapse rates are associated with the use of either modality alone. In an attempt to improve upon these dismal results, we treated seven PCNSL patients with HD-MTX-based induction therapy followed by thiotepa, busulfan, cyclophosphamide (TBC), and autologous stem cell transplant (ASCT), without WBRT. Six of these patients had at least one of the following poor prognostic features: Karnofsky performance status (KPS) ⩽50%, age >60 years, or relapsed disease. All but one patient tolerated the treatment well and experienced improvements in neurological function and overall performance status post-transplant. No treatment-induced neurotoxicity (dementia, ataxia, and incontinence) was observed although the follow-up is short. One early treatment-related death occurred in a patient with multiple comorbid medical conditions. The other six patients achieved a complete response (CR) after TBC and ASCT. Five patients are currently alive and relapse-free at 5, 8, 24, 36, and 42 months from diagnosis. One additional patient relapsed and died 33 months after diagnosis. Two of the seven patients received TBC/ASCT as the only treatment after disease progression following their initial chemotherapy and both remain relapse-free at the time of this report, 22 and 31 months post-TBC/ASCT. In conclusion, prolonged CR can be attained after chemotherapy-only treatment of poor prognosis PCNSL. Furthermore, this small series suggests that high-dose chemotherapy for PCNSL should include drugs that penetrate the CNS such as busulfan and thiotepa rather than standard lymphoma regimens such as BEAM.

Unrelated donor BMT recipients given pretransplant low-dose antithymocyte globulin have outcomes equivalent to matched sibling BMT: A matched pair analysis

Fifty-seven patients receiving unrelated donor (UD) BMT were matched for disease and stage with 57 recipients of genotypically matched related donor (MRD) BMT. All UD recipients were matched serologically for A and B and by high resolution for DR and DQ antigens. All patients received CsA and ‘short course’ methotrexate with folinic acid. Unrelated donor BMT patients also received thymoglobulin 4.5 mg/kg (6 mg/kg if <30 kg) in divided doses over 3 days pretransplant. For UD and RD BMT, respectively, incidence of acute GVHD grade II–IV was 19 ± 6% vs 36 ± 8%, grade III–IV 10 ± 6% vs 18 ± 7%, chronic GVHD 44 ± 8% vs 51 ± 8%, non-relapse mortality 15 ± 5% vs 8 ± 4% at 100 days, 28 ± 8% vs 36 ± 7% at 3 years. At 3 years, relapse was 45 ± 7% vs 42 ± 7%, and disease-free survival 39 ± 7% vs 37 ± 7%. None of these differences are significant. Three-year overall survival was identical at 42 ± 7%. For 29 patients with low/intermediate risk leukemia, disease-free survival was 68 ± 10% after UD BMT vs 59 ± 9% for RD BMT recipients (P = NS). Corresponding figures for high risk patients were 14 ± 7% and 21 ± 8%, respectively. We conclude that UD BMT recipients matched as above and given pretransplant ATG have similar outcomes to recipients of MRD BMT using conventional drug prophylaxis. Unrelated donor BMT should be considered in any circumstance where MRD BMT is routine.

Superior autologous blood stem cell mobilization from dose-intensive cyclophosphamide, etoposide, cisplatin plus G-CSF than from less intensive chemotherapy regimens

The study purpose was to determine if G-CSF plus dose-intensive cyclophosphamide 5.25 g/m2, etoposide 1.05 g/m2 and cisplatin 105 mg/m2 (DICEP) results in superior autologous blood stem cell mobilization (BSCM) than less intensive chemotherapy. From January 1993 until May 1997, 152 consecutive patients with non-Hodgkin’s lymphoma (n = 55), breast cancer (n = 47), Hodgkin’s disease (n = 14), multiple myeloma (n = 9), AML (n = 9), or other cancers (n = 18) initially underwent BSCM by one of three methods: Group 1: G-CSF alone × 4 days (n = 30). Group 2: disease-oriented chemotherapy, dosed to avoid blood transfusions, followed by G-CSF starting day 7 or 8, and apheresis day 13 or 14 (n = 82). Group 3: DICEP days 1–3, G-CSF starting day 14, and apheresis planned day 19, 20 or 21 (n = 40). A multivariate analysis was performed to determine which factors independently predicted BSCM. The median peripheral blood CD34+ (PB CD34+) cell count the morning of apheresis linearly correlated with the number of CD34+ cells removed per litre of apheresis that day. The median PB CD34+ cell count and median CD34+ cells × 106 removed per litre of apheresis were highest for Group 3, intermediate for Group 2, and lowest for Group 1. By multivariate analysis, mobilization group (3 > 2 > 1), disease other than AML, no prior melphalan or mitomycin-C, and less than two prior chemotherapy regimens predicted better BSCM. Out of 15 Group 3 patients who had infiltrated marrows, 11 had no detectable cancer in marrow and apheresis products after DICEP. These data suggest that DICEP results in superior BSCM than less intensive chemotherapy regimens.

Oncolytic Viral Therapy for Prostate Cancer: Efficacy of Reovirus as a Biological Therapeutic

Reovirus is a nonattenuated double-stranded RNA virus that exploits aberrant signaling pathways allowing selective cytotoxicity against multiple cancer histologies. The use of reovirus as a potential treatment modality for prostate cancer has not previously been described, and in this study evidence of in vitro and in vivo activity against prostate cancer was seen both in preclinical models and in six patients. The human prostate carcinoma cell lines PC-3, LN-CaP, and DU-145 exposed to replication-competent reovirus showed evidence of infection as illustrated by viral protein synthesis, cytopathic effect, and release of viral progeny. This oncolytic effect was found to be manifested through apoptosis, as DNA fragmentation, Apo 2.7 expression, Annexin V binding, and poly(ADP-ribose) polymerase cleavage were observed in live reovirus-infected cells, but not in uninfected or dead virus-treated cells. In vivo, hind flank severe combined immunodeficient/nonobese diabetic murine xenograft showed reduction in tumor size when treated with even a single intratumoral injection of reovirus. Finally, intralesional reovirus injections into a cohort of six patients with clinically organ-confined prostate cancer resulted in minimal side effects and evidence of antitumor activity. Histologic analysis after prostatectomy found a significant CD8 T-cell infiltration within the reovirus-injected areas as well as evidence of increased caspase-3 activity. These findings suggest that reovirus therapy may provide a promising novel treatment for prostate cancer and also imply a possible role for viral immune targeting of tumor.

Oncolytic Viral Therapy Using Reovirus

Current mainstays in cancer treatment such as chemotherapy, radiation therapy, hormonal manipulation, and even targeted therapies such as Trastuzumab (herceptin) for breast cancer or Iressa (gefitinib) for non-small cell lung cancer among others are limited by lack of efficacy, cellular resistance, and toxicity. Dose escalation and combination therapies designed to overcome resistance and increase efficacy are limited by a narrow therapeutic index. Oncolytic viruses are one such group of new biological therapeutics that appears to have a wide spectrum of anticancer activity with minimal human toxicity. Since the malignant phenotype of tumors is the culmination of multiple mutations that occur in genes eventually leading to aberrant signaling pathways, oncolytic viruses either natural or engineered specifically target tumor cells taking advantage of this abnormal cellular signaling for their replication. Reovirus is one such naturally occurring double-stranded RNA virus that exploits altered signaling pathways (including Ras) in a myriad of cancers. The ability of reovirus to infect and lyse tumors under in vitro, in vivo, and ex vivo conditions has been well documented previously by us and others. The major mechanism of reovirus oncolysis of cancer cells has been shown to occur through apoptosis with autophagy taking place during this process in certain cancers. In addition, the synergistic antitumor effects of reovirus in combination with radiation or chemotherapy have also been demonstrated for reovirus resistant and moderately sensitive tumors. Recent progress in our understanding of viral immunology in the tumor microenvironment has diverted interest in exploring immunologic mechanisms to overcome resistance exhibited by chemotherapeutic drugs in cancer. Thus, currently several investigations are focusing on immune potentiating of reovirus for maximal tumor targeting. This chapter therefore has concentrated on immunologic cell death induction with reovirus as a novel approach to cancer therapy used under in vitro and in vivo conditions, as well as in a clinical setting. Reovirus phase I clinical trials have shown indications of efficacy, and several phase II/III trials are ongoing at present. Reoviruss extensive preclinical efficacy, replication competency, and low toxicity profile in humans have placed it as an attractive anticancer therapeutic for ongoing clinical testing that are highlighted in this chapter.

Preoperative Chemoradiotherapy (Modified Eilber Protocol) Provides Maximum Local Control and Minimal Morbidity in Patients With Soft Tissue Sarcoma

BackgroundLocal recurrence rates of 15% to 30% after treatment of soft tissue sarcoma (STS) are still common but unacceptable. Our hypothesis was that a refined neoadjuvant chemotherapy and radiation protocol (modified Eilber protocol) improves local control rates while minimizing major morbidity.MethodsConsecutive patients with STS deep to the fascia of the extremity or trunk during 1984 to 1996 were treated with 3 days of doxorubicin (30 mg/day) and sequential radiation (300 cGy/day for 10 days). Wide excision with limb preservation was performed 4 to 8 weeks after radiation completion. Treatment complications, margins, local recurrence, and survival were prospectively documented.ResultsOf 75 patients, 66% had tumors >5 cm, and 71% were grade 2/3. In eight patients, negative margins were not achieved, and four of these had amputation (95% limb salvage). Three of the remaining four had local recurrence with a 5- and 7-year actuarial local control rate of 50% and 25%, respectively. In contrast, of the 67 patients with negative margins, a local control rate of 97% at 5 years and 94% at 7 years and an overall survival of 63% were achieved. Although margin (P = .001) and stage (P = .035) were correlated, these were not significant on multivariate Cox regression analysis. Risk factors for death included tumor stage (hazard ratio, 1.54; P = .001) and tumor grade (hazard ratio, 1.4; P = .02). Three patients (4%) required reoperation for tissue loss, and eight patients (10.6%) developed minor wound complications.ConclusionsThis modified Eilber protocol seems to maximize local control and minimize major wound complications for extremity/truncal STS.

Factors predicting engraftment of autologous blood stem cells : CD34+ subsets inferior to the total CD34+ cell dose

Data were analyzed on 178 consecutive patients (median age 43 years) who underwent autologous blood stem cell transplantation (ABSCT) at a single institution to determine if CD34+subsets (CD34+38−, CD34+33−, CD34+33+, CD34+41+) or various clinical factors affect hematopoietic engraftment independent of the total CD34+ cell dose/kg. Using Cox proportional hazards models, the factors independently associated with rapid neutrophil engraftment were higher CD34+ dose/kg, use of G-CSF post-ABSCT, and conditioning regimen (single-agent melphalan ± TBI slower). Factors independently associated with rapid platelet engraftment were higher CD34+ cell dose/kg, higher ratio of CD34+33−/total CD34+ cells infused, conditioning regimen (mitoxantrone, vinblastine, cyclophosphamide faster), and no CD34+ cell selection of the autograft. The CD34+ cell selection process seemed to deplete CD34+41+ cells to a greater extent than total CD34+cells which may explain our observation that it resulted in slower platelet engraftment. In conclusion, the total CD34+ dose/kg was a better predictor of hematopoietic engraftment following ABSCT than the dose of any CD34+ subset. Platelet engraftment, however, was also influenced by the ratio of CD34+33−/total CD34+cells for unmanipulated autografts, and possibly by the CD34+41+dose for autografts manipulated by CD34+ selection. The use of CD34+ subsets requires further investigation in predicting engraftment of autografts which undergo ex vivo manipulation.

CXCR4 Overexpression Is Associated with Poor Outcome in Females Diagnosed with Stage IV Non-small Cell Lung Cancer

Background: It has been proposed that the chemokine receptor, CXCR4, and its ligand, stromal cell-derived factor-1 (SDF-1), play a critical role in organ-specific tumor metastasis. High CXCR4 expression in resected non-small cell lung cancer (NSCLC) tumors is associated with poorer outcome; however, its effect on patient outcome in advanced NSCLC has not been explored. Methods: After institutional ethical approval was obtained, demographic details, clinical variables, and outcome data were collected on consecutive NSCLC patients diagnosed at the Tom Baker Cancer Centre from 2003 to 2006 (Glans-Look Lung Cancer Database). Formalin-fixed paraffin-embedded diagnostic biopsies from stage IV patients were obtained and tissue microarrays generated. CXCR4 expression within NSCLC cells was analyzed by quantitative fluorescent immunohistochemistry using the HistoRx PM-2000 platform and then correlated with clinical outcome. Results: Of 832 patients, 170 had samples suitable for tissue microarray generation and analysis. Automated immunohistochemistry for CXCR4 was successfully completed on all 170 patients. High expressors had a significantly poorer median overall survival of 2.7 months versus 5.6 months for the low expressors (p = 0.0468). This difference is driven by high-expressing females who have a median overall survival of 1.6 months versus 6.4 months for the low expressors (p = 0.006). Conclusions: CXCR4 is expressed in the majority of NSCLC tumors, and overexpression is associated with significantly poorer survival in stage IV NSCLC patients. Interestingly, this poor outcome is disproportionately represented in the female population. Our results suggest a gender-dependent difference in clinical outcome based on CXCR4 overexpression in stage IV NSCLC.

Reovirus as a Viable Therapeutic Option for the Treatment of Multiple Myeloma

Purpose: Despite the recent advances made in the treatment of multiple myeloma, the disease still remains incurable. The oncolytic potential of reovirus has previously been shown and is currently in phase III clinical trials for solid tumors. We tested the hypothesis that reovirus can successfully target human multiple myeloma in vitro, ex vivo, and in vivo without affecting human hematopoietic stem cell (HHSC) re-population/differentiation in a murine model that partially recapitulates human multiple myeloma. Experimental Design: Human myeloma cell lines and ex vivo tumor specimens were exposed to reovirus and oncolysis and mechanisms of cell death were assessed. RPMI 8226GFP+ cells were injected intravenously to non-obese diabetic/severe combined immune deficient (NOD/SCID) mice and treated with live reovirus (LV) or dead virus (DV). Multiple myeloma disease progression was evaluated via whole-body fluorescence and bone marrow infiltration. HHSCs exposed to LV/DV were injected to NOD/SCID mice and re-population/differentiation was monitored. Results: A total of six of seven myeloma cell lines and five of seven patient tumor specimens exposed to reovirus showed significant in vitro sensitivity. Tumor response of multiple myeloma by LV, but not DV, was confirmed by comparison of total tumor weights (P = 0.05), and bone marrow infiltration (1/6, LV; 5/6, DV). Mice injected with LV- or DV-exposed HHSCs maintained in vivo re-population/lineage differentiation showing a lack of viral effect on the stem cell compartment. Reovirus oncolysis was mediated primarily by activation of the apoptotic pathways. Conclusions: The unique ability of reovirus to selectively kill multiple myeloma while sparing HHSCs places it as a promising systemic multiple myeloma therapeutic for clinical testing. Clin Cancer Res; 18(18); 4962–72. ©2012 AACR.