Melanoma Helper Peptides Research Articles

A nano-enhanced vaccine for metastatic melanoma immunotherapy.

Aim: Despite the huge advancements in cancer therapies and treatments over the past decade, most patients with metastasized melanoma still die from the disease. This poor prognosis largely results from resistance to conventional chemotherapies and other cytotoxic drugs. We have previously identified 6 antigenic peptides derived from melanomas that have proven efficacious for activating CD4+ T cells in clinical trials for melanoma. Our aim was to improve pharmacodynamics, pharmacokinetic and toxicological parameters by individually encapsulating each of the 6 melanoma helper peptides within their own immunogenic nanoliposomes. Methods: We modified these liposomes as necessary to account for differences in the peptides’ chemical properties, resulting in 3 distinct formulations. To further enhance immunogenicity, we also incorporated KDO2, a TLR4 agonist, into the lipid bilayer of all nanoliposome formulations. We then conducted in vivo imaging studies in mice and ex vivo cell studies from 2 patient samples who both strongly expressed one of the identified peptides. Results: We demonstrate that these liposomes, loaded with the different melanoma helper peptides, can be readily mixed together and simultaneously delivered without toxicity in vivo. These liposomes are capable of being diffused to the secondary lymphoid organs very quickly and for at least 6 days. In addition, we show that these immunogenic liposomes enhance immune responses to specific peptides ex vivo. Conclusion: Lipid-based delivery systems, including nanoliposomes and lipid nanoparticles, have now been validated for pharmacological (small molecules, bioactive lipids) and molecular (mRNA, siRNA) therapeutic approaches. However, the utility of these formulations as cancer vaccines, delivering antigenic peptides, has not yet achieved the same degree of commercial success. Here, we describe the novel and successful development of a nanoliposome-based cancer vaccine for melanoma. These vaccines help to circumvent drug resistance by increasing a patient’s T cell response, making them more susceptible to checkpoint blockade therapy.

Trial to evaluate the immunogenicity and safety of a melanoma helper peptide vaccine plus incomplete Freund’s adjuvant, cyclophosphamide, and polyICLC (Mel63)

BackgroundPeptide vaccines designed to stimulate melanoma-reactive CD4+ T cells can induce T cell and antibody (Ab) responses, associated with enhanced overall survival. We hypothesized that adding toll-like receptor 3 agonist...

Statistical controversies in clinical research: early-phase adaptive design for combination immunotherapies

In recent years, investigators have asserted that the 3 + 3 design lacks flexibility, making its use in modern early-phase trial settings, such as combinations and/or biological agents, inefficient. More innovative approaches are required to address contemporary research questions, such as those posed in trials involving immunotherapies. We describe the implementation of an adaptive design for identifying an optimal treatment regimen, defined by low toxicity and high immune response, in an early-phase trial of a melanoma helper peptide vaccine plus novel adjuvant combinations. Operating characteristics demonstrate the ability of the method to effectively recommend optimal regimens in a high percentage of trials with reasonable sample sizes. The proposed design is a practical, early-phase, adaptive method for use with combined immunotherapy regimens. This design can be applied more broadly to early-phase combination studies, as it was used in an ongoing study of two small molecule inhibitors in relapsed/refractory mantle cell lymphoma.

Vaccination with Melanoma Helper Peptides Induces Antibody Responses Associated with Improved Overall Survival.

A melanoma vaccine incorporating six peptides designed to induce helper T-cell responses to melanoma antigens has induced Th1-dominant CD4(+) T-cell responses in most patients, and induced durable clinical responses or stable disease in 24% of evaluable patients. The present study tested whether this vaccine also induced antibody (Ab) responses to each peptide, and whether Ab responses were associated with T-cell responses and with clinical outcome. Serum samples were studied from 35 patients with stage III-IV melanomas vaccinated with 6 melanoma helper peptides (6MHP). IgG Ab responses were measured by ELISA. Associations with immune response and overall survival were assessed by log-rank test and χ(2) analysis of Kaplan-Meier data. Ab responses to 6MHP were detected by week 7 in 77% of patients, and increased to peak 6 weeks after the last vaccine and persisted to 6 months. Ab responses were induced most frequently to longer peptides. Of those with T-cell responses, 82% had early Ab responses. Survival was improved for patients with early Ab response (P = 0.0011) or with early T-cell response (P < 0.006), and was best for those with both Ab and T-cell responses (P = 0.0002). Vaccination with helper peptides induced both Ab responses and T-cell responses, associated with favorable clinical outcome. Such immune responses may predict favorable clinical outcome to guide combination immunotherapy. Further studies are warranted to understand mechanisms of interaction of these Abs, T-cell responses, and tumor control.

Erratum to: Immunologic hierarchy, class II MHC promiscuity, and epitope spreading of a melanoma helper peptide vaccine

Erratum to: Immunologic hierarchy, class II MHC promiscuity, and epitope spreading of a melanoma helper peptide vaccine

Immunologic hierarchy, class II MHC promiscuity, and epitope spreading of a melanoma helper peptide vaccine.

Immunization with a combination melanoma helper peptide (6MHP) vaccine has been shown to induce CD4(+) T cell responses, which are associated with patient survival. In the present study, we define the relative immunogenicity and HLA allele promiscuity of individual helper peptides and identify helper peptide-mediated augmentation of specific CD8(+) T cell responses. Thirty-seven participants with stage IIIB-IV melanoma were vaccinated with 6MHP in incomplete Freund's adjuvant. The 6MHP vaccine is comprised of 6 peptides representing melanocytic differentiation proteins gp100, tyrosinase, Melan-A/MART-1, and cancer testis antigens from the MAGE family. CD4(+) and CD8(+) T cell responses were assessed in peripheral blood and in sentinel immunized nodes (SIN) by thymidine uptake after exposure to helper peptides and by direct interferon-γ ELIspot assay against 14 MHC class I-restricted peptides. Vaccine-induced CD4(+) T cell responses to individual epitopes were detected in the SIN of 63 % (22/35) and in the peripheral blood of 38 % (14/37) of participants for an overall response rate of 65 % (24/37). The most frequently immunogenic peptides were MAGE-A3281-295 (49 %) and tyrosinase386-406 (32 %). Responses were not limited to HLA restrictions originally described. Vaccine-associated CD8(+) T cell responses against class I-restricted peptides were observed in 45 % (5/11) of evaluable participants. The 6MHP vaccine induces both CD4(+) and CD8(+) T cell responses against melanoma antigens. CD4(+) T cell responses were detected beyond reported HLA-DR restrictions. Induction of CD8(+) T cell responses suggests epitope spreading and systemic activity mediated at the tumor site.

A melanoma helper peptide vaccine increases Th1 cytokine production by leukocytes in peripheral blood and immunized lymph nodes.

BackgroundCancers produce soluble and cell-associated molecules that can suppress or alter antitumor immunity. Preclinical studies suggest the disease burden may alter the cytokine profile of helper T cell responses to cancer antigens. We studied cytokine production by helper T cells responding to vaccination with 6 melanoma helper peptides (6MHP) in blood and lymph nodes.MethodsTwenty-three patients with stage IIIB-IV melanoma received a 6MHP vaccine. Antigen-reactive T cells from blood and draining lymph nodes were cultured, exposed to antigen, and then supernatants (days 2 and 5) were assayed for Th1 and Th2 cytokines. Results from 4 time points were compared to pre-vaccine levels.ResultsCytokine responses to vaccinating peptides were observed in 83% of patients. Th1 favoring responses were most common (17 of 19 responders). The most abundant cytokines produced were IFN-γ and IL-5 in the PBMC’s. IL-2 responses predominated in cells obtained from draining lymph nodes in 2-day culture but not in 5-day cultures. Patients with clinically measurable disease produced similar levels of total cytokine and similar degree of Th1 polarization as patients with no evidence of disease (NED).ConclusionsThe MHC class II-associated peptides used in this study induced helper T cells with a Th1-biased cytokine response in both PBMC and sentinel immunized nodes. Most patients can mount a Th1 dominant response to these peptides. Future studies are needed to test newer vaccine adjuvants in combination with these peptides.Trial registrationCDR0000378171, Clinicaltrials: NCT00089219.

A multi-epitope melanoma helper peptide vaccine durably increases Th1 cytokine production by responding lymphocytes

Background Cancers produce soluble and cell-associated molecules that can suppress or alter antitumor immunity. Preclinical studies suggest the disease burden may alter the cytokine profile of helper T cell responses to cancer antigens. We studied cytokine production by helper T cells responding to vaccination with 6 melanoma helper peptides (6MHP) in blood and lymph nodes. We describe here the cytokine responses as change from baseline. Experimental design Thirty-nine patients with stage IIIB-IV melanoma received a 6MHP vaccine. Antigen-reactive T cells from blood and draining lymph nodes were exposed to antigen, and supernatants (days 2 and 5) were assayed by cytokine bead arrays for Th1 and Th2 cytokines. Results The greatest absolute cytokine responses detected were the levels of IFN-g and IL-5, though high levels of IL-2 were also produced early by lymph node-derived lymphocytes. Lymphocytes from patients with clinically measurable disease produced similar levels of total cytokine as patients with no evidence of disease (NED). For both disease statuses, the cytokine profile was Th1dominant in most patients. Total cytokine production and individual cytokine levels varied significantly among patients and varied over time but persisted up to nine months post-vaccine. Conclusions The MHC class II-associated peptides used in this study induced helper T cells with a Th1-biased cytokine response in both PBMC and sentinel immunized nodes in most patients. Patients with or without measurable disease can mount a Th1 dominant response to these peptides, which may persist long after the vaccination sequence. Future studies are needed to test newer vaccine adjuvants in combination with these peptides.

Immunologic hierarchy and promiscuity of melanoma helper peptides

Meeting abstracts Melanoma vaccines have been designed to expand specific CD8+ T-cells, but melanoma-reactive helper T-cells also can have antitumor activity. We previously observed clinical activity of a vaccine incorporating 6 melanoma helper peptides (6MHP), and found associations between CD4+ T

Antibody response to melanoma helper-peptide vaccine correlates with survival

Meeting abstracts A melanoma vaccine comprising 6 peptides presented by Class II MHC molecules was safe and induced CD4+ T cell responses in 81% of recipients. Circulating CD4+ T cell responses to these 6 melanoma helper peptides (6MHP) have been associated with patient survival. We hypothesized

A Randomized Phase II Trial of Multiepitope Vaccination with Melanoma Peptides for Cytotoxic T Cells and Helper T Cells for Patients with Metastatic Melanoma (E1602)

This multicenter randomized trial was designed to evaluate whether melanoma helper peptides augment cytotoxic T lymphocyte (CTL) responses to a melanoma vaccine and improve clinical outcome in patients with advanced melanoma. One hundred seventy-five patients with measurable stage IV melanoma were enrolled into 4 treatment groups, vaccinated with 12 MHC class I-restricted melanoma peptides to stimulate CTL (12 MP, group A), plus a tetanus peptide (group B), or a mixture of 6 melanoma helper peptides (6 MHP, group C) to stimulate helper T lymphocytes (HTL), or with 6 melanoma helper peptide (6 MHP) alone (group D), in incomplete Freund's adjuvant plus granulocyte macrophage colony-stimulating factor. CTL responses were assessed using an in vitro-stimulated IFN-γ ELIspot assay, and HTL responses were assessed using a proliferation assay. In groups A to D, respectively, CTL response rates to 12 melanoma peptides were 43%, 47%, 28%, and 5%, and HTL response rates to 6 MHP were in 3%, 0%, 40%, and 41%. Best clinical response was partial response in 7 of 148 evaluable patients (4.7%) without significant difference among study arms. Median overall survival (OS) was 11.8 months. Immune response to 6 MHP was significantly associated with both clinical response (P = 0.036) and OS (P = 0.004). Each vaccine regimen was immunogenic, but MHPs did not augment CTL responses to 12 melanoma peptides. The association of survival and immune response to 6 MHP supports further investigation of helper peptide vaccines. For patients with advanced melanoma, multipeptide vaccines should be studied in combination with other potentially synergistic active therapies.

The impact of a multi-epitope melanoma helper peptide vaccine on Th1 cytokine production by responding lymphocytes.

e19028 Background: Melanomas produce soluble and cell-associated molecules that can suppress or alter antitumor immunity. Preclinical studies suggest the disease burden may alter the cytokine profile of helper T cell responses to cancer antigens. To describe the vaccine-induced production of Th2 or Th1 responses to helper peptides in the setting of advanced melanoma, we measured cytokine production of helper T cells responding to vaccination by 6 melanoma helper peptides (6MHP). We then analyzed results by measurable disease status. Methods: Thirty-nine patients with stage IIIB-IV melanoma received a 6MHP vaccine as a part of the UVA Mel41 clinical trial. For analysis of this correlative endpoint, antigen-reactive T cells were exposed to antigen, and supernatants (days 2 and 5) were assayed by cytokine bead arrays for Th1 and Th2 cytokines. Results: The dominant Th1 and Th2 cytokines detected were IFN-g and IL-5, respectively, though high levels of IL-2 were also produced early by sentinel lymph node lymphocytes. Th1 cytokine responses predominated both pre and post vaccine. Peripheral blood lymphocytes from patients with clinically measurable disease produced similar levels of total cytokine as patients with no evidence of disease (111pg/ml versus 174pg/ml respectively, p=0.44). For both disease statuses, the cytokine profile was Th1-dominant in most patients. Total cytokine production varied significantly among patients and varied over time but persisted up to nine months post-vaccine. Conclusions: The MHC class II-associated peptides used in this study induced helper T cells with a Th1-biased cytokine response in both PBMC and sentinel immunized nodes. However, both groups of patients can mount a Th1 dominant response to these peptides, which may persist long after the vaccination sequence. Future studies are needed to test newer vaccine adjuvants in combination with these peptides.

First report of a randomized phase II trial of multi-epitope vaccination with melanoma peptides for cytotoxic T cells and helper T cells in patients with metastatic melanoma: An Eastern Cooperative Oncology Group Study (E1602).

8508 Background: This multicenter randomized trial was designed to evaluate, in advanced previously treated melanoma, whether melanoma helper peptides augment CD8+ T-cell responses to a melanoma va...

Helper T-Cell Responses and Clinical Activity of a Melanoma Vaccine With Multiple Peptides From MAGE and Melanocytic Differentiation Antigens

A phase I/II trial was performed to evaluate the safety and immunogenicity of a novel melanoma vaccine comprising six melanoma-associated peptides defined as antigenic targets for melanoma-reactive helper T cells. Source proteins for these peptides include MAGE proteins, MART-1/MelanA, gp100, and tyrosinase. Thirty-nine patients with stage IIIB to IV melanoma were vaccinated with this six-peptide mixture weekly at three dose levels, with a preceding phase I dose escalation and subsequent random assignment among the dose levels. Helper T-lymphocyte responses were assessed by in vitro proliferation assay and delayed-type hypersensitivity skin testing. Patients with measurable disease were evaluated for objective clinical response by Response Evaluation Criteria in Solid Tumors. Vaccination with the helper peptide vaccine was well tolerated. Proliferation assays revealed induction of T-cell responses to the melanoma helper peptides in 81% of patients. Among 17 patients with measurable disease, objective clinical responses were observed in two patients (12%), with response durations of 1 and 3.9+ years. Durable stable disease was observed in two additional patients for periods of 1.8 and 4.6+ years. Results of this study support the safety and immunogenicity of a vaccine comprised of six melanoma helper peptides. There is also early evidence of clinical activity.