In situ vaccination at a peripheral tumor site augments response against melanoma brain metastases.

BACKGROUND: Immune checkpoint inhibition (ICI) alone is not efficacious for a large number of patients with melanoma brain metastases. We previously established an in situ vaccination (ISV) regimen combining radiation and immunocytokine to enhance response to ICIs. Here, we tested whether ISV inhibits the development of brain metastases in a murine melanoma model. METHODS: B78 (GD2+) melanoma 'primary' tumors were engrafted on the right flank of C57BL/6 mice. After 3-4 weeks, primary tumors were treated with ISV (radiation (12 Gy, day 1), α-GD2 immunocytokine (hu14.18-IL2, days 6-10)) and ICI (α-CTLA-4, days 3, 6, 9). Complete response (CR) was defined as no residual tumor observed at treatment day 90. Mice with CR were tested for immune memory by re-engraftment with B78 in the left flank and then the brain. To test ISV efficacy against metastases, tumors were also engrafted in the left flank and brain of previously untreated mice. Tumors were analyzed by quantitative reverse transcription-PCR, immunohistochemistry, flow cytometry and multiplex cytokine assay. RESULTS: ISV+α-CTLA-4 resulted in immune memory and rejection of B78 engraftment in the brain in 11 of 12 mice. When B78 was engrafted in brain prior to treatment, ISV+α-CTLA-4 increased survival compared with ICI alone. ISV+α-CTLA-4 eradicated left flank tumors but did not elicit CR at brain sites when tumor cells were engrafted in brain prior to ISV. ISV+α-CTLA-4 increased CD8+ and CD4+ T cells in flank and brain tumors compared with untreated mice. Among ISV + α-CTLA-4 treated mice, left flank tumors showed increased CD8+ infiltration and CD8+:FOXP3+ ratio compared with brain tumors. Flank and brain tumors showed minimal differences in expression of immune checkpoint receptors/ligands or Mhc-1. Cytokine productions were similar in left flank and brain tumors in untreated mice. Following ISV+α-CTLA-4, production of immune-stimulatory cytokines was greater in left flank compared with brain tumor grafts. CONCLUSION: ISV augmented response to ICIs in murine melanoma at brain and extracranial tumor sites. Although baseline tumor-immune microenvironments were similar at brain and extracranial tumor sites, response to ISV+α-CTLA-4 was divergent with reduced infiltration and activation of immune cells in brain tumors. Additional therapies may be needed for effective antitumor immune response against melanoma brain metastases.

Phase IIa, randomized placebo-controlled trial of single high dose cholecalciferol (vitamin D3) and daily Genistein (G-2535) versus double placebo in men with early stage prostate cancer undergoing prostatectomy.

INTRODUCTION AND OBJECTIVES: Prostate cancer (PCa) represents an important target for chemoprevention given its prolonged natural history and high prevalence. Epidemiologic and laboratory data suggest that vitamin D and genistein (soy isoflavone) may decrease PCa progression. The effect of vitamin D on prostate epithelial cell proliferation and differentiation is well documented and genistein may augment this affect through inhibition of the CYP24 enzyme, which is responsible for intracellular vitamin D metabolism. In addition, both genistein and vitamin D inhibit the intraprostatic synthesis of prostaglandin E2, an important mediator of inflammation. The objectives of this prospective multicenter trial were to compare prostate tissue calcitriol levels and down-stream related biomarkers in men with localized prostate cancer randomized to receive cholecalciferol and genistein versus placebo cholecalciferol and placebo genistein during the pre-prostatectomy period. METHODS: Men undergoing radical prostatectomy were randomly assigned to one of two treatment groups: (1) cholecalciferol (vitamin D3) 200,000 IU as one dose at study entry plus genistein (G-2535), 600 mg daily or (2) placebo cholecalciferol day 1 and placebo genistein PO daily for 21-28 days prior to radical prostatectomy. Serum and tissue analyses were performed and side-effects recorded. RESULTS: A total of 15 patients were enrolled, 8 in the placebo arm and 7 in the vitamin D3 + genistein (VD + G) arm. All patients were compliant and completed the study. No significant differences in side effect profiles were noted. Utilization of the VD + G trended toward increased calcitriol serum concentrations when compared to placebo (0.104 ± 0.2 vs. 0.0013 ± 0.08; p=0.08); however, prostate tissue levels did not increase. Calcidiol levels did not change (p=0.5). Immunohistochemistry for marker analyses using VECTRA automated quantitation revealed a increase in AR expression (p=0.04) and a trend toward increased TUNEL staining (p=0.1) in prostate cancer tissues in men randomized to receive VD + G compared to placebo. CONCLUSIONS: In this first study testing the combination of a single, large dose of cholecalciferol and daily genistein, the agents were well tolerated. While an increase in AR expression suggesting differentiation was observed, it is difficult to draw firm conclusions regarding the bioactivity of the combination given the sample size.

A phase 2 study of weekly temsirolimus and bortezomib for relapsed or refractory B-cell non-Hodgkin lymphoma: A Wisconsin Oncology Network study.

BACKGROUND: Proteasome inhibitors and mammalian target of rapamycin inhibitors each have activity in various B-cell malignancies and affect distinct cellular pathways. Their combination has demonstrated synergy in vitro and in mouse models. METHODS: The authors conducted a single-arm, phase 2 trial of combined temsirolimus and bortezomib in patients with relapsed and refractory B-cell non-Hodgkin lymphoma (NHL) using a dosing scheme that was previously tested in multiple myeloma. The patients received bortezomib and temsirolimus weekly on days 1, 8, 15, and 22 of a 35-day cycle. RESULTS: Of 39 patients who received treatment, 3 achieved a complete response (7.7%; 95% confidence interval [CI], 1.6%-21%), and 9 had a partial response (PR) (23%; 95% CI, 11%-39%). Thus, the overall response rate (12 of 39 patients) was 31% (95% CI, 17%-48%), and the median progression-free survival was 4.7 months (95% CI, 2.1-7.8 months; 2 months for patients with diffuse large B-cell lymphoma [n = 18], 7.5 months for those with mantle cell lymphoma [n = 7], and 16.5 months for those with follicular lymphoma [n = 9]). Two extensively treated patients with diffuse large B-cell lymphoma achieved a complete response. There were no unexpected toxicities from the combination. CONCLUSIONS: The current results demonstrate that the combination of a mammalian target of rapamycin inhibitor and a proteasome inhibitor is safe and has activity in patients with heavily pretreated B-cell NHL. Further studies with this combination are warranted in specific subtypes of NHL.

Brief report: Measuring the attitudes of health care professionals in Dane County toward adolescent immunization with HPV vaccine.

OBJECTIVE: Evaluate regional health care professionals' views of human papillomavirus (HPV) vaccination recommendations for adolescent patients through a mailed survey. METHODS: A 16-question self-administered questionnaire was mailed to 518 physicians, physician assistants, and nurse practitioners in Dane County, Wis, working in family medicine, pediatrics, or gynecology in September 2006. The survey addressed health care professionals' willingness to recommend the HPV vaccine, populations they would target for a recommendation, and justifications provided to patients regarding the benefits of HPV vaccination. RESULTS: Of the health care professionals who were mailed a survey, 39% responsed. The majority (95%) of professionals were willing to recommend the HPV vaccine to their adolescent patients. Most practitioners (67%) were planning to recommend the vaccine to their female patients only and are most comfortable vaccinating patients >10 years of age. Health care professionals were looking to their own health profession organizations for vaccination recommendations. CONCLUSION: Health care professionals in family medicine, pediatrics, and gynecology in Dane County, Wis, have positive attitudes regarding HPV vaccine recommendation for their adolescent patients.

A phase I study of immunization using particle-mediated epidermal delivery of genes for gp100 and GM-CSF into uninvolved skin of melanoma patients.

PURPOSE: We examined in vivo particle-mediated epidermal delivery (PMED) of cDNAs for gp100 and granulocyte macrophage colony-stimulating factor (GM-CSF) into uninvolved skin of melanoma patients. The aims of this phase I study were to assess the safety and immunologic effects of PMED of these genes in melanoma patients. EXPERIMENTAL DESIGN: Two treatment groups of six patients each were evaluated. Group I received PMED with cDNA for gp100, and group II received PMED with cDNA for GM-CSF followed by PMED for gp100 at the same site. One vaccine site per treatment cycle was biopsied and divided for protein extraction and sectioning to assess transgene expression, gold-bead penetration, and dendritic cell infiltration. Exploratory immunologic monitoring of HLA-A2(+) patients included flow cytometric analyses of peripheral blood lymphocytes and evaluation of delayed-type hypersensitivity to gp100 peptide. RESULTS: Local toxicity in both groups was mild and resolved within 2 weeks. No systemic toxicity could be attributed to the vaccines. Monitoring for autoimmunity showed no induction of pathologic autoantibodies. GM-CSF transgene expression in vaccinated skin sites was detected. GM-CSF and gp100 PMED yielded a greater infiltration of dendritic cells into vaccine sites than did gp100 PMED only. Exploratory immunologic monitoring suggested modest activation of an antimelanoma response. CONCLUSIONS: PMED with cDNAs for gp100 alone or in combination with GM-CSF is well tolerated by patients with melanoma. Moreover, pathologic autoimmunity was not shown. This technique yields biologically active transgene expression in normal human skin. Although modest immune responses were observed, additional investigation is needed to determine how to best utilize PMED to induce antimelanoma immune responses.

Randomized prospective phase III trial of difluoromethylornithine vs placebo in preventing recurrence of completely resected low risk superficial bladder cancer.

PURPOSE: Ornithine decarboxylase catalyzes the rate limiting step in polyamine synthesis and its activity can be inhibited by difluoromethylornithine, which has been shown in preclinical studies, to prevent bladder cancer. MATERIALS AND METHODS: To assess the ability of difluoromethylornithine to prevent recurrence of low risk superficial bladder cancer, 454 patients with newly diagnosed (283) or occasionally recurrent (171), stage Ta (425) or T1 (29), grade 1 (263) or grade 2 (191), completely resected urothelial cancer were randomized to receive 1 gm difluoromethylornithine daily or placebo for 1 year. Patients were followed with cystoscopy every 3 months for 2 years and then semiannually for 2 years or until first recurrence. Index and recurrent tumors underwent central pathology review. RESULTS: No serious drug related toxicities were seen in either arm. Two patients died of bladder cancer at 2 and 4 years after randomization, both in the difluoromethylornithine arm. At 42 months followup, 103 patients in the difluoromethylornithine arm (46%) and 97 in the placebo arm (43%) (p = 0.30) experienced at least 1 tumor recurrence. Over 73% of recurrences occurred within 1 year in each arm. Each arm had similar responses for each stratification factor. During the 42 months of followup, 10 (4.4%) difluoromethylornithine and 9 (3.9%) placebo treated patients had progression to TIS or grade 3 disease, and 2 (0.9%) in the difluoromethylornithine arm and none in the placebo arm developed stage T2+ cancers. CONCLUSIONS: A year of difluoromethylornithine did not prevent recurrence of completely resected low risk superficial bladder cancer, when started shortly after surgery.

Phase II study of interferon-alpha and doxycycline for advanced renal cell carcinoma.

OBJECTIVE: To assess the efficacy and toxicity of the combination of interferon-alpha and doxycycline in patients with metastatic renal cell carcinoma and to assess the effect of this treatment on serum vascular endothelial growth factor (VEGF) levels. PATIENTS AND METHODS: Seventeen patients with Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 and life expectancy greater than 4 months with radiologically evident advanced renal cell carcinoma were enrolled. Eight patients had prior nephrectomy and 10 patients were treated within 4 months of their diagnosis. Treatment consisted of interferon-alpha up to 9 million units subcutaneously three times per week and doxycycline 300 mg orally twice per day for weeks one and three of each four-week cycle. Toxicity was evaluated on a biweekly basis and response on a bimonthly basis. VEGF plasma levels were assessed monthly as a measure of potential antiangiogenic effect. RESULTS: No objective responses were seen. The mean duration of study was 2.6 cycles (range: 0.8-6.0 cycles). Three patients (17%) tolerated therapy and displayed stable disease for greater than four months. Five patients withdrew from study before the first response evaluation. Ten patients experienced grade 2 gastrointestinal toxicity requiring dose reduction of doxycycline. Eight patients experienced grade 2 fatigue requiring dose reduction of interferon. VEGF plasma levels were initially suppressed in patients who demonstrated progressive disease but not in patients with stable disease. CONCLUSION: This regimen of doxycycline and interferon-alpha was not efficacious as treatment for renal cell carcinoma. Plasma VEGF levels were significantly decreased during the first two cycles of treatment, but this does not correlate with clinical outcome.

Phase II study of weekly low-dose paclitaxel for relapsed and refractory non-Hodgkin's lymphoma: a Wisconsin Oncology Network Study.

This study was performed to determine the clinical activity and safety of weekly low-dose paclitaxel (90 mg/m2) given as a 1-hour infusion in patients with relapsed and refractory non-Hodgkin's lymphoma (NHL). Thirty patients were treated on a phase II protocol conducted at the University of Wisconsin Comprehensive Cancer Center and within the Wisconsin Oncology Network (WON). A cycle of therapy was defined as paclitaxel at 90 mg/m2 weekly for 6 consecutive weeks followed by a 2-week rest period. Cycles were repeated as long as there was no disease progression or unacceptable toxicity. In general, the patients were heavily pretreated with a median of 4 prior therapies (range 2-11), and 73% were refractory to the most recent systemic therapy. The median age was 70 (range 44-97). All NHL histological subtypes were eligible. Of the 30 eligible patients enrolled, 26 were evaluable for response and 28 for toxicity. The overall response rate was 23% (95% confidence interval (CI) 9.0-43.7%). One patient had a complete response, and 5 patients had partial responses. The median response duration was 3.2 months (range 1.4-11.8 months). The median event-free survival was 1.9 months. The major toxicity was neuropathy. Despite the limited marrow reserve in this patient population, myelosuppression was minimal. Paclitaxel given in this dose and schedule has modest activity in previously treated non-Hodgkin's lymphoma. The response rate appears similar to other reports using different doses and schedules. Myelosuppression appears less with this schedule than with other schedules.

On the estimation of the binomial probability in multistage clinical trials.

Due to the optional sampling effect in a sequential design, the maximum likelihood estimator (MLE) following sequential tests is generally biased. In a typical two-stage design employed in a phase II clinical trial in cancer drug screening, a fixed number of patients are enrolled initially. The trial may be terminated for lack of clinical efficacy of treatment if the observed number of treatment responses after the first stage is too small. Otherwise, an additional fixed number of patients are enrolled to accumulate additional information on efficacy as well as on safety. There have been numerous suggestions for design of such two-stage studies. Here we establish that under the two-stage design the sufficient statistic, i.e. stopping stage and the number of treatment responses, for the parameter of the binomial distribution is also complete. Then, based on the Rao-Blackwell theorem, we derive the uniformly minimum variance unbiased estimator (UMVUE) as the conditional expectation of an unbiased estimator, which in this case is simply the maximum likelihood estimator based only on the first stage data, given the complete sufficient statistic. Our results generalize to a multistage design. We will illustrate features of the UMVUE based on two-stage phase II clinical trial design examples and present results of numerical studies on the properties of the UMVUE in comparison to the usual MLE.

NXS2 murine neuroblastomas express increased levels of MHC class I antigens upon recurrence following NK-dependent immunotherapy.

We evaluated recurrent NXS2 neuroblastoma tumors that developed following NK- or T-cell-mediated immunotherapy in tumor-bearing mice. Recurrent tumors developed following an NK-dependent antitumor response using a suboptimal dose of hu14.18-IL2, a humanized IL-2 immunocytokine targeted to the GD(2)-ganglioside. This treatment initially induced complete resolution of measurable tumor in the majority of mice, followed, however, by delayed tumor recurrence in some mice. These recurrent NXS2 tumors revealed markedly enhanced (> fivefold) MHC class I antigen expression when compared with NXS2 tumors growing in PBS-treated control mice. A similar level of enhanced MHC class I antigen-expression could be induced on NXS2 cells in vitro by culturing with interferon gamma, and was associated with reduced susceptibility to both NK-cell-mediated tumor cell lysis and antibody-dependent cellular cytotoxicity in vitro. In contrast, Flt3-ligand treatment of NXS2-bearing mice induced a protective T-cell-dependent antitumor memory response. Recurrent NXS2 tumors that developed following Flt3-L therapy revealed a decreased expression of MHC class I antigens. While NXS2 tumors are susceptible to in vivo destruction following either hu14.18-IL2 or Flt3-ligand immunotherapies, these results suggest that some tumor cells may be selected to survive and progress by expressing either higher or lower levels of MHC class I antigen in order to resist either NK- or T-cell-mediated antitumor responses, respectively.