Abstract
INTRODUCTION
Cytomegalovirus (CMV) antigens are excellent anti-tumor immunotherapeutic targets in glioblastoma (GBM). The PERFORMANCE trial (IRB-pro34208, IND-15846) assessed the ...feasibility, safety and optimal adjuvant temozolomide (TMZ) regimen to be used with PEP-CMV vaccination in adults with newly-diagnosed GBM.
METHODS
Seropositive CMV patients (n=16) were randomized into two arms and treated with standard of care RT-TMZ (SOC) (150-200 mg/m2/day on days 1-5 per 28-day cycle) or dose-intensive TMZ (DI) (75-100 mg/m2/day on days 1-21 per 28-day cycle). Patients received intradermal PEP-CMV vaccines (500μg of CMVpp65 synthetic long peptide (SLP) mixed with Montanide ISA-51) on days 23, 37 and 51 following TMZ. All patients received tetanus/diphtheria toxoid (Td) preconditioning at the vaccination site on day 22. Serum cytokine levels were measured pre-vaccination, 1-hour and 2-hours post vaccination. PEP-CMV specific circulating PBMCs were quantified at baseline and after each vaccine.
RESULTS
Of the 16 trial patients, 7 experienced site-reactions, 4 had grade-II Immune Related Adverse Events (IRAEs), and 4 experienced flu-like grade-III IRAEs. Inflammatory cytokines (IL-2, IFNγ, MIP-1a, IL-8, TNFα, and IL-10) were elevated in patients with grade-III responses 2-hours post vaccine 1. Td p2/p30 specific PBMC levels were similar between IRAEs. However, pp65 responsive PBMCs were elevated at baseline in patients with grade-III reactions compared to site-reaction suggesting pre-existing peptide specific responses may lead to increased vaccine immunogenicity. PBMCs specific for pp65 increased with number of consecutive vaccines. No difference in progression free survival (PFS) or overall survival (OS) was observed between TMZ regimens.
CONCLUSION
PEP-CMV vaccination with Td preconditioning is feasible and generates immune responses specific to pp65 in patients with newly diagnosed GBM. Importantly, IRAEs were associated with antitumor efficacy. The mild IRAEs in PERFORMANCE are likely indicative of vaccine potency and can be managed through standard premedication as has been used in other trials with similar IRAEs.
BACKGROUND: Despite aggressive surgery, high-dose focused radiation, and multimechanistic chemotherapy, malignant gliomas (MG) remain almost universally fatal. The inherent biologic specificity of ...immunotherapy offers the prospect of targeting neoplastic cells more precisely. Dendritic cells (DCs) are endowed with an extraordinary ability to activate CD4+ and CD8+ T-cells, and DCs loaded with antigens derived from tumor cells (CMV pp65-LAMP mRNA) have the potential to induce potent antitumor immunity. Furthermore, regulatory T-cells (TRegs) which induce a state of reversible immunosuppression in MG and can be functionally inactivated with anti-CD25 antibody (Ab), while dramatically enhance vaccine-induced immune responses. METHODS: Eligible were gross totally resected patients (pts) with newly diagnosed GBM. Pts underwent leukapheresis followed by standard of care radiation/temozolomide (XRT/TMZ) therapy. After completion of XRT/TMZ, up to 12 cycles of TMZ 200 mg/m2/x5d were administered. Around Day 21 of the 1st cycle pts also received: anti-CD25 Ab treatment and vaccine #1. Vaccines #2 and #3 were given biweekly following vaccine#1. On Day 21 of the 2nd TMZ cycle Vaccine #4 was administered. Pts were followed with serial MRIs until disease progression. RESULTS: 7 patients (5 males) were treated. No adverse events attributable to vaccine treatment were observed. Median progression free survival was 23.5 months (95% CI:1.7 to 54.1). Median overall survival was 30.3 months (95% CI:11.8 to 60.8). Overall survival was calculated from the start of vaccine therapy to time of death or last contact if alive. CONCLUSION: Treatment with XRT/TMZ, DC vaccine and anti- CD25 Ab was well tolerated and produced encouraging PFS and OS resulting in now ongoing Phase I study. Due to the lack of adverse events the number of vaccines had been increased to 8 (vs. 4) and anti-CD25 antibody is being given with the first two cycles (vs. with 1st cycle only) of adjuvant TMZ.
Abstract
INTRODUCTION
While primary GBM is largely heterogeneous and devoid of homogeneously expressed neoantigens, mutant IDH1 (R132H) is a uniformly expressed hallmark in >70% of low grade gliomas. ...As such, IDH1 mutations represent a potentially valuable vaccination target.
METHODS
Here, we report an update on the immunogenicity results of the mutant IDH1 peptide vaccine alone and in combination with temozolomide (TMZ). In the phase I RESIST clinical trial (NCT02193347), patients with recurrent and resectable IDH1 R132H mutant grade 2 glioma received peptide vaccinations composed of 500 µg of mutant IDH1 peptide and 150 µg of GM-CSF mixed 1:1 with Montanide adjuvant prior to surgical resection. Vaccines 1, 2, and 3 were given 15 (+/-) 3 days apart. 7-12 days after vaccine 3, patients underwent standard of care tumor (SOC) resection. After resection, patients with grade 2 gliomas were given up to 15 doses of peptide vaccine in combination with TMZ regimens while patients with transformed grade 3 gliomas were given up to 15 doses of peptide vaccine in combination with SOC radiation therapy + TMZ regimens. T cell responses against the mutant peptide were measured after vaccine 3 using IFN-γ ELISPOT and intracellular flow cytometry for IL-2, TNFα,and IFNγ.
RESULTS
3/20 patients were taken off the study before completion of study related activities. 1/20 patients progressed before completion of all vaccines. Out of 134 total doses of vaccine delivered, only one dose generated a grade 2 or higher injection site reaction according to the CTCAE guidelines. Vaccination with the mutant peptide led to an overall increase in IFN-γ+ spot-forming splenocytes specific to the mutant peptide (p=0.0408).
CONCLUSION
Administering the mutant IDH1 peptide vaccine in patients with recurrent IDH-mutant gliomas was able to induce anti-IDH1 R132H immune responses in this initial phase I study.
Rokitansky-Aschoff sinuses (R-As) are epithelial invaginations that extend down the gallbladder wall through the smooth muscle gaps and by this pathway they reach the subserosal connective tissue. We ...report here 5 cases of mucin-containing R-As that ruptured, and as a result, extracellular mucin escaped into the adjacent stroma. They were compared with 10 mucinous carcinomas of the gallbladder. Three cases of mucin-containing R-As accompanied by abundant extracellular mucin deposits with epithelial strips, glands and papillary structures were misinterpreted as mucinous carcinomas. Because of this, the patients were subjected to a second unnecessary radical surgical procedure. In the remaining 2 cases, the extracellular mucin associated with R-As was acellular and regarded as focal. Three patients were men and 2 women whose ages ranged from 2 to 71 years (average age 52 y). The youngest patient was a 2-year-old boy in whom the mucin-containing R-As were discovered incidentally by magnetic resonance imaging. He was later diagnosed with metachromatic leukodystrophy. The remaining 4 patients complained of right upper quadrant pain and had a thickened gallbladder wall identified by computed tomography and magnetic resonance imaging. There were gallstones in 3 patients. The R-As located in the lamina propria contained mucin but were not cystically dilated whereas those located in the subserosa were mucin-filled and often cystically dilated. Detached fragments of biliary epithelium, small glands, and papillary structures lacking cytologic atypia and mitotic figures were identified in the abundant mucin deposits located in the subserosa of 3 cases. The overlying surface gallbladder epithelium exhibited papillary hyperplasia with focal intestinal metaplasia in 2 patients, one of which had metachromatic leukodystrophy. The lack of reactivity for carcinoembryonic antigen and p53 and the low proliferative activity as measured by MIB-1 labeling index provided additional support to the benign nature of the lesion. Clues to separate mucin-containing R-As from mucinous carcinoma are provided. All 5 patients with mucin-containing R-As are disease free 8 months to 7 years after surgery (median follow-up of 39 mo).
BACKGROUND: Despite aggressive surgery, high-dose focused radiation, and multimechanistic chemotherapy, malignant gliomas (MG) remain almost universally fatal. The inherent biologic specificity of ...immunotherapy offers the prospect of targeting neoplastic cells more precisely. Dendritic cells (DCs) are endowed with an extraordinary ability to activate CD4+ and CD8+ T-cells, and DCs loaded with antigens derived from tumor cells (CMV pp65-LAMP mRNA) have the potential to induce potent antitumor immunity. Furthermore, regulatory T-cells (TRegs) which induce a state of reversible immunosuppression in MG and can be functionally inactivated with anti-CD25 antibody (Ab), while dramatically enhance vaccine-induced immune responses. METHODS: Eligible were gross totally resected patients (pts) with newly diagnosed GBM. Pts underwent leukapheresis followed by standard of care radiation/temozolomide (XRT/TMZ) therapy. After completion of XRT/TMZ, up to 12 cycles of TMZ 200 mg/m2/x5d were administered. Around Day 21 of the 1st cycle pts also received: anti-CD25 Ab treatment and vaccine #1. Vaccines #2 and #3 were given biweekly following vaccine#1. On Day 21 of the 2
nd
TMZ cycle Vaccine #4 was administered. Pts were followed with serial MRIs until disease progression. RESULTS: 7 patients (5 males) were treated. No adverse events attributable to vaccine treatment were observed. Median progression free survival was 23.5 months (95% CI:1.7 to 54.1). Median overall survival was 30.3 months (95% CI:11.8 to 60.8). Overall survival was calculated from the start of vaccine therapy to time of death or last contact if alive. CONCLUSION: Treatment with XRT/TMZ, DC vaccine and anti- CD25 Ab was well tolerated and produced encouraging PFS and OS resulting in now ongoing Phase I study. Due to the lack of adverse events the number of vaccines had been increased to 8 (vs. 4) and anti-CD25 antibody is being given with the first two cycles (vs. with 1
st
cycle only) of adjuvant TMZ.
Both glioblastoma (GBM) and dementia are devastating diseases with limited treatments that are usually not curative. Having clinically diagnosed dementia with an associated biopsy-proven etiology and ...a coexisting GBM diagnosis is a rare occurrence. The relationship between the development of neurodegenerative dementia and GBM is unclear, as there are conflicting reports in the literature. We present two cases of simultaneous biopsy-proven dementia, one with Alzheimer's disease (AD) and GBM, and one with cerebral amyloid angiopathy (CAA) and GBM. We discuss how these diseases may be associated. Whether one pathologic process begins first or develops concurrently is unknown, but certain molecular pathways of dementia and GBM appear directly related while others inversely related. Further investigations of these close molecular relationships between dementia and GBM could lead to development of improved diagnostic tools and therapeutic interventions for both diseases.
The histologic subtypes of malignant glial neoplasms range from anaplastic astrocytoma to the most deadly World Health Organization (WHO) Grade IV glioblastoma (GBM), the most common primary brain ...tumor in adults. Over the past 40 years, only modest advancements in the treatment of GBM tumors have been reached. Current therapies are predominantly for palliative endpoints rather than curative, although some treatment modalities have been shown to extend survival in particular cases. Patients undergoing current standard of care therapy, including surgical resection, radiation therapy, and chemotherapy, have a median survival of 12-15 months, with less than 25% of patients surviving up to two years and fewer than 10% surviving up to five years. A variety of factors contribute to standard treatment failure, including highly invasive tumor grade at the time of diagnosis, the intrinsic resistance of glioma cells to radiation therapy, the frequent impracticality of maximal tumor resection of eloquent cortical structures, and the fragile intolerance of healthy brain for cytotoxic therapies. Treatment with immunotherapy is a potential answer to the aforementioned problems, as the immune system can be harnessed and educated to license rather potent antitumor responses in a highly specific and safe fashion. One of the most promising vehicles for immunotherapy is the use of dendritic cells, which are professional antigen-presenting cells that are highly effective in the processing of foreign antigens and the education of soon-to-be activated T cells against established tumors. The work outlined in this dissertation encompasses the potential of dendritic cell therapy, the current limitations of reaching full efficacy with this platform, and the recent efforts employed to overcome such barriers. This work spans the characterization and preclinical testing of utilizing protein antigens such as tetanus-diphtheria toxoid to pre-condition the injection site prior to dendritic cell vaccination against established tumors expressing tumor-specific antigens. Chapter 1 comprises an overview of the current standard therapies for malignant brain tumors. Chapters 2 and 3 provide a review of immunotherapy for malignant gliomas in the setting of preclinical animal models and discuss issues relevant to the efficacy of dendritic cell vaccines for targeting of GBM. Chapters 4 provides the rationale, methodology, and results of research to improve the lymph node homing and immunogenicity of tumor antigen-specific dendritic cell vaccines in mouse models and in patients with newly diagnosed GBM. Chapter 5 delineates the interactions discovered through efforts in Chapter 4 that comprise protein antigen-specific CD4+ T cell responses to induced chemokines and how these interactions result in increased dendritic cell migration and antitumor responses. Lastly, Chapter 6 discusses the future utility of migration of DC vaccines as a surrogate for antitumor responses and clinical outcomes. This dissertation comprises original research as well as figures and illustrations from previously published material used to exemplify distinct concepts in immunotherapy for cancer. These published examples were reproduced with permission in accordance with journal and publisher policies described in the Appendix. In summary, this work 1) identifies inefficient lymph node homing of peripherally administered dendritic cells as one of the glaring barriers to effective dendritic cell immunotherapy, 2) provides answers to overcome this limitation with the use of readily available pre-conditioning recall antigens, 3) has opened up a new line of investigation for interaction between recall responses and host chemokines to activate immune responses against a separate antigen, and 4) provides future prospects of utilizing chemokines as adjuvants for additional immunotherapies targeting aggressive tumors. Together, these studies hold great promise to improve the responses in patients with GBM.
Dissertation
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