Survival of African-American and Caucasian men after sipuleucel-T immunotherapy: outcomes from the PROCEED registry.

PURPOSE: African Americans experience greater prostate cancer risk and mortality than do Caucasians. An analysis of pooled phase III data suggested differences in overall survival (OS) between African American and Caucasian men receiving sipuleucel-T. We explored this in PROCEED (NCT01306890), an FDA-requested registry in over 1900 patients with metastatic castration-resistant prostate cancer (mCRPC) treated with sipuleucel-T. PATIENTS AND METHODS: OS for patients who received ≥1 sipuleucel-T infusion was compared between African American and Caucasian men using an all patient set and a baseline prostate-specific antigen (PSA)-matched set (two Caucasians to every one African American with baseline PSAs within 10% of each other). Univariable and multivariable analyses were conducted. Survival data were examined using Kaplan-Meier and Cox proportional hazard methodologies. RESULTS: Median follow-up was 46.6 months. Overall survival differed between African American and Caucasian men with hazard ratios (HR) of 0.81 (95% confidence interval [CI]: 0.68-0.97, P = 0.03) in the all patient set and 0.70 (95% CI: 0.57-0.86, P < 0.001) in the PSA-matched set. Median OS was longer in African Americans than in Caucasian men for both analysis sets, e.g., 35.3 and 25.8 months, respectively, in the PSA-matched set. Similar results were observed in the all patient set. Differences were larger when treatment began at lower baseline PSA; curves were more similar among patients with higher baseline PSA. In patients with baseline PSA below the median, the HR was 0.52 (95% CI: 0.37-0.72, P < 0.001), with median OS of 54.3 versus 33.4 months. Known prognostic factors and African American race (multivariable analyses; HR: 0.60, 95% CI: 0.48-0.74, P < 0.001) were independently associated with OS. Use of post-sipuleucel-T anticancer interventions was balanced between races. CONCLUSION: In this exploratory analysis of a registry including nearly 12% African American men with mCRPC, OS was significantly different between African Americans and Caucasians, indicating further research is warranted.

Dendritic cell vaccination plus low-dose doxorubicin for the treatment of spontaneous canine hemangiosarcoma.

Angiosarcoma is a deadly neoplasm of the vascular endothelium. Metastatic disease is often present at diagnosis, and 5-year survival is only 10-35%. Although there exist no immunocompetent mouse models of angiosarcoma with which to study immune-based approaches to therapy, angiosarcoma is a major killer of companion dogs, responsible for up to 2% of all canine deaths in some susceptible breeds or an estimated 120,000 per year in the US. The canine disease (HSA) often presents in the spleen as acute hemoabdomen secondary to splenic rupture. Even if life-saving splenectomy is performed, median overall survival (OS) is only 48 days, and 1-year survival is negligible. Here we report the analysis of a pilot phase I open-label trial of chemo-immunotherapy performed on consecutively presenting splenectomized canines with histologically verified HSA. Subjects received an abbreviated course of low-dose doxorubicin plus alpha interferon and an autologous dendritic cell-therapy reported to enhance durable CD8+ memory. Disease was monitored monthly by abdominal ultrasound, chest X-ray, and echocardiogram. Median OS in the per protocol population was 109 days including one of five animals that died cancer-free at 16 months after documented resolution of relapsed disease. These results indicate that therapeutic administration of chemo-immunotherapy is both feasible and safe, substantiating the rationale for additional veterinary and human clinical studies.

Assessment of Safety and Immunogenicity of PVX-410 Vaccine With or Without Lenalidomide in Patients With Smoldering Multiple Myeloma: A Nonrandomized Clinical Trial.

Importance: Increasing evidence suggests the significance of the role of the immune system in the progression of smoldering multiple myeloma (SMM) to symptomatic multiple myeloma (MM). Boosting the immune system via vaccination in the earlier, asymptomatic SMM stage may provide a novel strategy to prevent or slow progression to active MM. Objective: To determine the safety, tolerability, immunogenicity, and anti-MM activity of the PVX-410 multipeptide vaccine with or without lenalidomide. Design, Setting, and Participants: This 3-cohort phase 1/2a multicenter dose-escalation study accrued 22 adults (≥18 years) with SMM with normal organ/marrow function who were human leukocyte antigen A2-positive and at moderate or high risk of progression to MM. Interventions: Patients received 6 doses of PVX-410 emulsified in Montanide ISA 720 VG, 0.4 mg total (0.1 mg/peptide) (n = 3) or 0.8 mg total (0.2 mg/peptide) (n = 9), biweekly via subcutaneous injection. In the combination cohort (n = 10), patients also received three 21-day cycles of lenalidomide, 25 mg, orally daily every 28 days. All patients received 0.5 mL (1 mg) poly-ICLC (2 mg/mL) via intramuscular injection with each PVX-410 dose. Main Outcomes and Measures: Adverse events (AEs) were evaluated using the Common Terminology Criteria for Adverse Events, version 4.03. PVX-410-specific T lymphocytes by flow cytometry to assess tetramer and interferon (IFN)-γ response. Disease response was assessed by investigators using the International Myeloma Working Group (IMWG) and modified European Group for Bone Marrow Transplantation (EBMT) criteria. Results: Overall, 14 (64%) patients were men and the median age at enrollment was 56 years in the monotherapy and 57 years in the combination cohorts (overall range, 39-82 years). Six of 12 patients in the monotherapy and 9 of 10 in the combination cohorts were at moderate risk. The PVX-410 vaccine was well tolerated. The most common AEs were mild-to-moderate injection site reactions and constitutional symptoms. Of note, PVX-410 was immunogenic as monotherapy (10 of 11 patients) and in combination with lenalidomide (9 of 9 patients), as demonstrated by an increase in percentage of tetramer-positive cells and IFN-γ cells in the CD3+CD8+ cell population. The combination resulted in greater mean fold increases in proportions of CD3+CD8+ T cells that were tetramer-positive and IFN-γ-positive, statistically significant for IFN-γ-positive cells after 2 and 4 vaccinations. An increase and persistence of vaccine-specific effector memory cells was noted. In total, 7 of 12 patients in the PVX-410-alone cohort had stable disease with 2 of 3 (low-dose cohort) and 1 of 9 of the target-dose cohort progressing (median TTP, 36 weeks), whereas 5 of 12 patients in the combination cohort showed, clinical response, with 1 patient progressing (median TTP not reached). Conclusions and Relevance: Overall, these results suggest that the vaccine is safe and immunogenic in this patient population and support continued study of PVX-410 in SMM. Trial Registration: ClinicalTrials.gov identifier: NCT01718899.

Assessment of in vivo anti-tumor activity of human umbilical vein endothelial cell vaccines prepared by various antigen forms.

Human umbilical vein endothelial cell (HUVEC) vaccine has been proved as an effective whole-cell vaccine, but the modest therapeutic anti-tumor efficiency limits its clinical use. Various antigen forms, including paraformaldehyde-fixed HUVEC, glutaraldehyde-fixed HUVEC, HUVEC lysate and live HUVEC, have been intensively used in HUVEC vaccine preparation, however, the most effective antigen form has not yet been identified. In the present study, these four commonly used antigen forms were used to prepare vaccines named Para-Fixed-EC, Glu-Fixed-EC, Lysate-EC, and Live-EC respectively, and the anti-tumor efficacy of these four vaccines was investigated. Results showed that Live-EC exhibited the most favorable anti-tumor growth and metastasis effects among the four vaccines in both H22 hepatocellular carcinoma and Lewis lung cancer models. High titer anti-HUVEC antibodies were detected in Live-EC immunized mice sera, and the immune sera of Live-EC group could significantly inhibit HUVEC proliferation and tube formation. Moreover, T cells isolated from Live-EC immunized mice exhibited strong cytotoxicity against HUVEC cells, with an increasing IFN-γ and decreasing Treg production in Live-EC immunized mice. Finally, CD31 immunohistochemical analysis of the excised tumors verified a significant reduction in vessel density after Live-EC vaccination, which was in accordance with the anti-tumor efficiency. Taken together, all the results proved that live HUVEC was the most effective antigen form to induce robust HUVEC specific antibody and CTL responses, which could lead to the significant inhibition of tumor growth and metastasis. We hope the present findings would provide a rationale for the further optimization of HUVEC vaccine.

Group sequential monitoring based on the weighted log-rank test statistic with the Fleming-Harrington class of weights in cancer vaccine studies.

In recent years, immunological science has evolved, and cancer vaccines are now approved and available for treating existing cancers. Because cancer vaccines require time to elicit an immune response, a delayed treatment effect is expected and is actually observed in drug approval studies. Accordingly, we propose the evaluation of survival endpoints by weighted log-rank tests with the Fleming-Harrington class of weights. We consider group sequential monitoring, which allows early efficacy stopping, and determine a semiparametric information fraction for the Fleming-Harrington family of weights, which is necessary for the error spending function. Moreover, we give a flexible survival model in cancer vaccine studies that considers not only the delayed treatment effect but also the long-term survivors. In a Monte Carlo simulation study, we illustrate that when the primary analysis is a weighted log-rank test emphasizing the late differences, the proposed information fraction can be a useful alternative to the surrogate information fraction, which is proportional to the number of events. Copyright © 2016 John Wiley & Sons, Ltd.

Sipuleucel-T for the Treatment of Metastatic Hormone-Relapsed Prostate Cancer: A NICE Single Technology Appraisal; An Evidence Review Group Perspective.

The National Institute for Health and Care Excellence (NICE) invited Dendreon, the company manufacturing sipuleucel-T, to submit evidence for the clinical and cost effectiveness of sipuleucel-T for asymptomatic or minimally symptomatic, metastatic, non-visceral hormone-relapsed prostate cancer patients in whom chemotherapy is not yet clinically indicated, as part of NICE's single technology appraisal process. The comparator was abiraterone acetate (AA) or best supportive care (BSC). The School of Health and Related Research at the University of Sheffield was commissioned to act as the Evidence Review Group (ERG). This paper describes the company submission (CS), ERG review, and subsequent decision of the NICE Appraisal Committee (AC). The ERG produced a critical review of the clinical and cost-effectiveness evidence of sipuleucel-T based upon the CS. Clinical-effectiveness data relevant to the decision problem were taken from three randomised controlled trials (RCTs) of sipuleucel-T and a placebo (PBO) comparator of antigen-presenting cells (APC) being re-infused (APC-PBO) (D9901, D9902A and D9902B), and one RCT (COU-AA-302) of AA plus prednisone vs. PBO plus prednisone. Two trials reported a significant advantage for sipuleucel-T in median overall survival compared with APC-PBO: for trial D9901, an adjusted hazard ratio (HR) 0.47; (95 % confidence interval [CI] 0.29, 0.76) p < 0.002; for D9902B, adjusted HR 0.78 (95 % CI 0.61, 0.98) p = 0.03. There was no significant difference between groups in D9902A, unadjusted HR 0.79 (95 % CI 0.48, 1.28) p = 0.331. Sipuleucel-T and APC-PBO groups did not differ significantly in time to disease progression, in any of the three RCTs. Most adverse events developed within 1 day of the infusion, and resolved within 2 days. The CS included an indirect comparison of sipuleucel-T (D9902B) and AA plus prednisone (COU-AA-302). As trials differed in prior use of chemotherapy, an analysis of only chemotherapy-naïve patients was included, in which the overall survival for sipuleucel-T and AA was not significantly different, HR 0.94 (95 % CI 0.69, 1.28) p = 0.699. The ERG had several concerns regarding the data and assumptions incorporated within the company's cost-effectiveness analyses and conducted exploratory analyses to quantify the impact of making alternative assumptions or using alternative data inputs. The deterministic incremental cost-effectiveness ratio (ICER) for sipuleucel-T vs. BSC when using the ERG's preferred data and assumptions was £ 108,585 per quality-adjusted life-year (QALY) in the whole licensed population and £ 61,204/QALY in the subgroup with low prostate-specific antigen at baseline. The ERG also conducted an incremental analysis comparing sipuleucel-T with both AA and BSC in the chemotherapy-naïve subgroup. Sipuleucel-T had a deterministic ICER of £ 111,682/QALY in this subgroup, when using the ERG's preferred assumptions, and AA was extendedly dominated. The ERG also concluded that estimates of costs and benefits for AA should be interpreted with caution given the limitations of the indirect comparison. The AC noted that the ICER for sipuleucel-T was well above the range usually considered cost effective, and did not recommend sipuleucel-T for the treatment of asymptomatic or minimally symptomatic, metastatic, non-visceral hormone-relapsed prostate cancer.

Quantitative TCR:pMHC Dissociation Rate Assessment by NTAmers Reveals Antimelanoma T Cell Repertoires Enriched for High Functional Competence.

Experimental models demonstrated that therapeutic induction of CD8 T cell responses may offer protection against tumors or infectious diseases providing that T cells have sufficiently high TCR/CD8:pMHC avidity for efficient Ag recognition and consequently strong immune functions. However, comprehensive characterization of TCR/CD8:pMHC avidity in clinically relevant situations has remained elusive. In this study, using the novel NTA-His tag-containing multimer technology, we quantified the TCR:pMHC dissociation rates (koff) of tumor-specific vaccine-induced CD8 T cell clones (n = 139) derived from seven melanoma patients vaccinated with IFA, CpG, and the native/EAA or analog/ELA Melan-A(MART-1)(26-35) peptide, binding with low or high affinity to MHC, respectively. We observed substantial correlations between koff and Ca(2+) mobilization (p = 0.016) and target cell recognition (p < 0.0001), with the latter independently of the T cell differentiation state. Our strategy was successful in demonstrating that the type of peptide impacted on TCR/CD8:pMHC avidity, as tumor-reactive T cell clones derived from patients vaccinated with the low-affinity (native) peptide expressed slower koff rates than those derived from patients vaccinated with the high-affinity (analog) peptide (p < 0.0001). Furthermore, we observed that the low-affinity peptide promoted the selective differentiation of tumor-specific T cells bearing TCRs with high TCR/CD8:pMHC avidity (p < 0.0001). Altogether, TCR:pMHC interaction kinetics correlated strongly with T cell functions. Our study demonstrates the feasibility and usefulness of TCR/CD8:pMHC avidity assessment by NTA-His tag-containing multimers of naturally occurring polyclonal T cell responses, which represents a strong asset for the development of immunotherapy.

Human vaccines & immunotherapeutics: news.

While a PhD candidate, doing my thesis at the Oak Ridge National Laboratory, Biology Division under Dr. Charles Congdon, my introduction to the immune response was studying graft vs. host (GVH) disease as a consequence of bone marrow transplantation in mice. The sequalae of GVH was impressive, and demonstrated the potential of negative clinical consequences of the immune system. The idea of harnessing this immunological phenomena in cancer therapy was appealing even in the late 1960s. The problem was that at the time T-cells as a component of the immune system were identified but not defined. We moved to soluble antigen stimulation in mice and recognized and described the post antigen stimulation changes in lymphatic tissue germinal centers during the first 48 h after the induction of the humoral immune response. We described the extracellular localization of soluble antigens on the surface of dendritic reticular cells of the stroma, directing a response of B-cells to produce antibody against non-self. The ensuing reaction was the rapid proliferation of B-cells toward antibody secreting plasma cells.

Anticancer patent landscape and technology assessment of Indian public-funded research institutes and organizations.

INTRODUCTION: This review discusses the various drug therapeutic targets and latest technologies of anticancer patents from 10 Indian public-funded research organizations covering more than 150 esteemed institutes. We have identified and reported the leading assignee and inventors along with their collaboration network and, thereby, have analyzed the various patent trends, geographical distributions, citation maps, Derwent World Patents Index, international patent classification analysis and the like. AREAS COVERED: This article provides the insights of 1905 patent documents from 191 families and discusses in-depth anticancer technology through categorization studies at the level of drug discovery, drug development and treatment and diagnosis. In addition, various cancer targets were correlated with recent technologies so as to identify the white spaces for upcoming technologies. EXPERT OPINION: Over a period of 13 years (1990 - 2013) the main focus of Indian cancer research was in the field of synthetic chemistry and natural extracts followed by the pharmaceutical compositions and combinations, whereas, the white spaces for future cancer remedy were identified from research in the areas of cancer stem cell lines, vaccines, gene therapy, nano formulations with targeted drug delivery systems as core and latest technologies.

AE37 peptide vaccination in prostate cancer: a 4-year immunological assessment updates on a phase I trial.

In our recent phase I trial, we demonstrated that the AE37 vaccine is safe and induces HER-2/neu-specific immunity in a heterogeneous population of HER-2/neu (+) prostate cancer patients. Herein, we tested whether one AE37 boost can induce long-lasting immunological memory in these patients. Twenty-three patients from the phase I study received one AE37 boost 6-month post-primary vaccinations. Local/systemic toxicities were evaluated following the booster injection. Immunological responses were monitored 1-month (long-term booster; LTB) and 3-year (long-term immunity; LTI) post-booster by delayed-type hypersensitivity, IFN-γ ELISPOT and proliferation assays. Regulatory T cell (Treg) frequencies, plasma transforming growth factor-ß (TGF-ß) and indoleamine 2,3-deoxygenase (IDO) activity levels were also determined at the same time points. The AE37 booster was safe and well tolerated. Immunological monitoring revealed vaccine-specific long-term immunity in most of the evaluated patients during both LTB and LTI, although individual levels of immunity during LTI were decreased compared with those measured 3 years earlier during LTB. This was paralleled with increased Tregs, TGF-ß levels and IDO activity. One AE37 booster generated long-term immunological memory in HER-2/neu (+) prostate cancer patients, which was detectable 3 years later, albeit with a tendency to decline. Boosted patients had favorable clinical outcome in terms of overall and/or metastasis-free survival compared with historical groups with similar clinical characteristics at diagnosis. We suggest that more boosters and/or concomitant disarming of suppressor circuits may be necessary to sustain immunological memory, and therefore, further studies to optimize the AE37 booster schedule are warranted.

New treatment options for castration-resistant prostate cancer.

PURPOSE: Published efficacy and safety data from clinical trials of three recently approved agents for the management of metastatic castration-resistant prostate cancer (CRPC) are reviewed. SUMMARY: Sipuleucel-T is approved by the Food and Drug Administration (FDA) for the treatment of asymptomatic or minimally symptomatic patients with CRPC. In a placebo-controlled Phase III clinical trial, the use of sipuleucel-T was associated with an average improvement in median overall survival of 4.1 months. Abiraterone acetate and cabazitaxel are approved by FDA as second-line treatments for patients with CRPC who experience disease progression during first-line docetaxel therapy. In Phase III trials, abiraterone acetate was associated with improved overall survival relative to placebo use (14.8 months versus 10.9 months), and cabazitaxel was found to confer an overall survival advantage over mitoxantrone therapy (median survival, 15.1 months versus 12.7 months), corresponding to a 30% reduction in the relative risk of death (hazard ratio, 0.7; 95% confidence interval, 0.59-0.83; p < 0.0001). The three agents range in cost from $40,000 to $93,000 for a full course of therapy. Sipuleucel therapy entails leukapheresis procedures for the collection of autologous cells used in dose preparation, requiring careful planning and coordination of care. CONCLUSION: Sipuleucel-T, abiraterone acetate, and cabazitaxel offer new options for the treatment of patients with CRPC, including those with disease resistant to standard first-line therapies. The agents' varying administration requirements, as well as patient-specific factors and cost issues, are key considerations in the drug selection process.

TAPCells, the Chilean dendritic cell vaccine against melanoma and prostate cancer.

Here we summarize 10 years of effort in the development of a biomedical innovation with global projections. This innovation consists of a novel method for the production of therapeutic dendritic-like cells called Tumor Antigen Presenting Cells (TAPCells®). TAPCells-based immunotherapy was tested in more than 120 stage III and IV melanoma patients and 20 castration-resistant prostate cancer patients in a series of phase I and I/II clinical trials. TAPCells vaccines induced T cell-mediated memory immune responses that correlated with increased survival in melanoma patients and prolonged prostate-specific antigen doubling time in prostate cancer patients. Importantly, more than 60% of tested patients showed a Delayed Type Hypersensitivity (DTH) reaction against the lysates, indicating the development of anti-tumor immunological memory that correlates with clinical benefits. The in vitro analysis of the lysate mix showed that it contains damage-associated molecular patterns such as HMBG-1 protein which are capable to improve, through Toll-like receptor-4, maturation and antigen cross-presentation of the dendritic cells (DC). In fact, a Toll-like receptor-4 polymorphism correlates with patient clinical outcomes. Moreover, Concholepas concholepas hemocyanin (CCH) used as adjuvant proved to be safe and capable of enhancing the immunological response. Furthermore, we observed that DC vaccination resulted in a three-fold increase of T helper-1 lymphocytes releasing IFN-γ and a two-fold increase of T helper-17 lymphocytes capable of producing IL-17 in DTH+ with respect to DTH- patients. Important steps have been accomplished for TAPCells technology transfer, including patenting, packaging and technology assessment. Altogether, our results indicate that TAPCells vaccines constitute an exceptional Chilean national innovation of international value.

TAPCells, the Chilean dendritic cell vaccine against melanoma and prostate cancer

Here we summarize 10 years of effort in the development of a biomedical innovation with global projections. This innovation consists of a novel method for the production of therapeutic dendritic-like cells called Tumor Antigen Presenting Cells (TAPCells®). TAPCells-based immunotherapy was tested in more than 120 stage III and IV melanoma patients and 20 castration-resistant prostate cancer patients in a series of phase I and I/II clinical trials. TAPCells vaccines induced T cell-mediated memory immune responses that correlated with increased survival in melanoma patients and prolonged prostate-specific antigen doubling time in prostate cancer patients. Importantly, more than 60% of tested patients showed a Delayed Type Hypersensitivity (DTH) reaction against the lysates, indicating the development of anti-tumor immunological memory that correlates with clinical benefits. The in vitro analysis of the lysate mix showed that it contains damage-associated molecular patterns such as HMBG-1 protein which are capable to improve, through Toll-like receptor-4, maturation and antigen cross-presentation of the dendritic cells (DC). In fact, a Toll-like receptor-4 polymorphism correlates with patient clinical outcomes. Moreover, Concholepas concholepas hemocyanin (CCH) used as adjuvant proved to be safe and capable of enhancing the immunological response. Furthermore, we observed that DC vaccination resulted in a three-fold increase of T helper-1 lymphocytes releasing IFN-γ and a two-fold increase of T helper-17 lymphocytes capable of producing IL-17 in DTH+ with respect to DTH- patients. Important steps have been accomplished for TAPCells technology transfer, including patenting, packaging and technology assessment. Altogether, our results indicate that TAPCells vaccines constitute an exceptional Chilean national innovation of international value.

Pharmaco-economic aspects of sipuleucel-T.

Sipuleucel-T, a new autologous active cellular immunotherapy, is indicated for metastatic castration-resistant prostate cancer. This Commentary aims to highlight pharmaco-economic aspects relating to the clinical evidence, cost-effectiveness and reimbursement of sipuleucel-T. Today, there is still uncertainty surrounding the clinical benefit of sipuleucel-T and existing evidence relates to the efficacy of sipuleucel-T in a structured setting rather than to its effectiveness in a real-world setting. Due to the clinical uncertainty, there may be scope to introduce a 'coverage with evidence development' scheme, where sipuleucel-T is reimbursed subject to further evidence being generated about its (cost-)effectiveness. Given the high price for a modest effectiveness, sipuleucel-T is unlikely to be cost-effective. However, other societal considerations may matter such as the fact that sipuleucel-T is an end-of-life treatment. A case can be made to apply weights to quality-adjusted life years accrued in the later stages of terminal diseases, thereby improving the cost-effectiveness of sipuleucel-T. Also, risk-sharing arrangements could be considered where the manufacturer shares the risk with the third-party payer that the product may or may not be effective for a particular patient. However, the current absence of markers to identify eligible patients and to assess treatment response inhibits the implementation of a risk-sharing arrangement for sipuleucel-T.

Sipuleucel-T for the treatment of metastatic prostate cancer: promise and challenges.

In the past 18 mo, three new life-prolonging therapies have been approved by the US. Food and Drug Administration for the treatment of men with metastatic castration-resistant prostate cancer (mCRPC), including sipuleucel-T, the first therapeutic vaccine approved for this disease. With very low toxicity and a demonstrable overall survival benefit, sipuleucel-T offers a promising new therapy and validates further investigation into other immunotherapy approaches for prostate cancer patients. However, questions about its mechanism of action, concerns about its cost, and its optimal sequencing in the prostate cancer treatment landscape may be limiting the adoption of sipuleucel-T. This review summarizes the state-of-the-science with respect to immunotherapy approaches for men with prostate cancer, provides information about the clinical development as well as the strengths and concerns associated with sipuleucel-T, and offers initial insights about where this promising treatment may best fit in the therapeutic landscape.