Personalized peptide vaccination: a new approach for advanced cancer as therapeutic cancer vaccine

Phase II Study of Personalized Peptide Vaccination with Both a Hepatitis C Virus-Derived Peptide and Peptides from Tumor-Associated Antigens for the Treatment of HCV-Positive Advanced Hepatocellular Carcinoma Patients

Objective. To evaluate safety and immune responses of personalized peptide vaccination (PPV) for hepatitis C virus- (HCV-) positive advanced hepatocellular carcinoma (HCC). Patients and Methods. Patients diagnosed with HCV-positive advanced HCC were eligible for this study. A maximum of four HLA-matched peptides were selected based on the preexisting IgG responses specific to 32 different peptides, which consisted of a single HCV-derived peptide at core protein positions 35-44 (C-35) and 31 peptides derived from 15 different tumor-associated antigens (TAAs), followed by subcutaneous administration once per week for 8 weeks. Peptide-specific cytotoxic T lymphocyte (CTL) and IgG responses were measured before and after vaccination. Results. Forty-two patients were enrolled. Grade 3 injection site skin reaction was observed in 2 patients, but no other PPV-related severe adverse events were noted. Peptide-specific CTL responses before vaccination were observed in only 3 of 42 patients, but they became detectable in 23 of 36 patients tested after vaccination. Peptide-specific IgG responses were also boosted in 19 of 36 patients. Peptide-specific IgG1 responses to both C-35 and TAA-derived peptides could be potentially prognostic for overall survival. Conclusion. Further clinical study of PPV would be warranted for HCV-positive advanced HCC, based on the safety and strong immune induction.

Immunological evaluation of peptide vaccination for cancer patients with the HLA-A26 allele

To develop a peptide vaccine for cancer patients with the HLA-A26 allele, which is a minor population worldwide, we investigated the immunological responses of HLA-A26(+) /A26(+) cancer patients to four different CTL epitope peptides under personalized peptide vaccine regimens. In personalized peptide vaccine regimens, two to four peptides showing positive peptide-specific IgG responses in pre-vaccination plasma were selected from the four peptide candidates applicable for HLA-A26(+) /A26(+) cancer patients and administered s.c. Peptide-specific CTL and IgG responses along with cytokine levels were measured before and after vaccination. Cell surface markers in PBMCs and plasma cytokine levels were also measured. In this study, 21 advanced cancer patients, including seven lung, three breast, two pancreas, and two colon cancer patients, were enrolled. Their HLA-A26 genotypes were HLA-A26:01 (n = 24), HLA-A26:03 (n = 10), and HLA-A26:02 (n = 8). One, 14, and 6 patients received two, three, and four peptides, respectively. Grade 1 or 2 skin reactions at the injection sites were observed in the majority of patients, but no severe adverse events related to the vaccination were observed. Peptide-specific CTL responses were augmented in 39% or 22% of patients after one or two cycles of vaccination, respectively. Notably, peptide-specific IgG were augmented in 63% or 100% of patients after one or two cycles of vaccination, respectively. Personalized peptide vaccines with these four CTL epitope peptides could be feasible for HLA-A26(+) advanced cancer patients because of their safety and higher rates of immunological responses.

Personalized peptide vaccination for cervical cancer patients who have received prior platinum-based chemotherapy

A feasibility study was performed to evaluate the immunological efficacy and safety of a personalized peptide vaccine (PPV) for cervical cancer patients who have received platinum-based chemotherapy. A total of 24 patients with standard chemotherapy-resistant cervical cancer, including 18 recurrent cases, were enrolled in this study and received a maximum of 4 peptides based on HLA-A types and IgG levels to the vaccine candidate peptides in pre-vaccination plasma. The parental protein expression of most of the vaccine peptides was confirmed in the cervical cancer tissues. No vaccine-related systemic grade 3 or 4 adverse events were observed in any patients. Due to disease progression, 2 patients failed to complete the first cycle of vaccinations (sixth vaccination). Cytotoxic T-lymphocyte (CTL) or IgG responses specific for the peptides used for vaccination were augmented in half of cases after the first cycle. The median overall survival was 8.3 months. The clinical responses of the evaluable 18 cases consisted of 1 case with a partial response and 17 cases with disease progression; the remaining 6 cases were not evaluable. Performance status, injection site skin reaction and circulating PD-1⁺CD4⁺ T-cells were significantly prognostic of overall survival, and multivariate analysis also indicated that the performance status and circulating PD-1⁺CD4⁺ T-cells were prognostic. Because of the safety and immunological efficacy of PPV and the possible prolongation of overall survival, further clinical trials of PPV at a larger scale in advanced or recurrent cervical cancer patients who have received prior platinum-based chemotherapy are recommended.

A novel vaccine for mantle cell lymphoma based on targeting cyclin D1 to dendritic cells via CD40

Background

Mantle cell lymphoma (MCL) is a distinct clinical pathologic subtype of B cell non-Hodgkin’s lymphoma often associated with poor prognosis. New therapeutic approaches based on boosting anti-tumor immunity are needed. MCL is associated with overexpression of cyclin D1 thus rendering this molecule an interesting target for immunotherapy.

Methods

We show here a novel strategy for the development of recombinant vaccines carrying cyclin D1 cancer antigens that can be targeted to dendritic cells (DCs) via CD40.

Results

Healthy individuals and MCL patients have a broad repertoire of cyclin D1-specific CD4⁺ and CD8⁺ T cells. Cyclin D1-specific T cells secrete IFN-γ. DCs loaded with whole tumor cells or with selected peptides can elicit cyclin D1-specific CD8⁺ T cells that kill MCL tumor cells. We developed a recombinant vaccine based on targeting cyclin D1 antigen to human DCs via an anti-CD40 mAb. Targeting monocyte-derived human DCs in vitro with anti-CD40-cyclin D1 fusion protein expanded a broad repertoire of cyclin D1-specific CD4⁺ and CD8⁺ T cells.

Conclusions

This study demonstrated that cyclin D1 represents a good target for immunotherapy and targeting cyclin D1 to DCs provides a new strategy for mantle cell lymphoma vaccine.

Electronic supplementary material

The online version of this article (doi:10.1186/s13045-015-0131-7) contains supplementary material, which is available to authorized users.

Phase I trial of a cancer vaccine consisting of 20 mixed peptides in patients with castration-resistant prostate cancer: dose-related immune boosting and suppression

The heterogeneity expression of tumor-associated antigens (TAA) and variability of human T cell repertoire suggest that effective cancer vaccine requires induction of a wide breadth of cytotoxic T lymphocyte (CTL) specificities. This can be achieved with vaccines targeting multiple TAA. We evaluated the safety and immune dynamics of a cancer vaccine consisting of 20 mixed peptides (KRM-20) designed to induce CTLs against 12 different TAA in patients with castration-resistant prostate cancer (CRPC). Patients received each of three different randomly assigned doses of KRM-20 (6, 20, or 60 mg) once a week for 6 weeks. KRM-20 was applicable for patients with positive human leukocyte antigen (HLA) A2, A3, A11, A24, A26, A31 or A33 alleles, which cover the majority of the global population. To evaluate the minimum immunological effective dose (MIED), peptide-specific CTL and immunoglobulin G (IgG) responses, and immune suppressive subsets were evaluated during the vaccination. Total of 17 patients was enrolled. No serious adverse drug reactions were encountered. The MIED of KRM-20 in CTL or IgG response calculated by logistic regression model was set as 16 or 1.6 mg, respectively. The frequency of immune suppressive subsets was fewer in the 20 mg cohort than that in 6 or 60 mg cohort. Clinical responses determined by prostate-specific antigen levels were two partial responses (from the 20 mg cohort), five no changes and ten progressive diseases. Twenty milligrams of KRM-20 could be recommended for further studies because of the safety and ability to augment CTL activity.

Personalized peptide vaccination for advanced colorectal cancer

We have developed a novel approach in cancer immunotherapy, the personalized peptide vaccination (PPV), in which human leukocyte antigen (HLA)-matched peptides are selected on the basis of preexisting host immunity before vaccination. Recently, we demonstrated the feasibility of PPV in previously treated patients with advanced colorectal cancer, thus warranting further clinical development of this approach.

Mass spectrometry of human leukocyte antigen class I peptidomes reveals strong effects of protein abundance and turnover on antigen presentation

HLA class I molecules reflect the health state of cells to cytotoxic T cells by presenting a repertoire of endogenously derived peptides. However, the extent to which the proteome shapes the peptidome is still largely unknown. Here we present a high-throughput mass-spectrometry-based workflow that allows stringent and accurate identification of thousands of such peptides and direct determination of binding motifs. Applying the workflow to seven cancer cell lines and primary cells, yielded more than 22,000 unique HLA peptides across different allelic binding specificities. By computing a score representing the HLA-I sampling density, we show a strong link between protein abundance and HLA-presentation (p < 0.0001). When analyzing overpresented proteins - those with at least fivefold higher density score than expected for their abundance - we noticed that they are degraded almost 3 h faster than similar but nonpresented proteins (top 20% abundance class; median half-life 20.8h versus 23.6h, p < 0.0001). This validates protein degradation as an important factor for HLA presentation. Ribosomal, mitochondrial respiratory chain, and nucleosomal proteins are particularly well presented. Taking a set of proteins associated with cancer, we compared the predicted immunogenicity of previously validated T-cell epitopes with other peptides from these proteins in our data set. The validated epitopes indeed tend to have higher immunogenic scores than the other detected HLA peptides. Remarkably, we identified five mutated peptides from a human colon cancer cell line, which have very recently been predicted to be HLA-I binders. Altogether, we demonstrate the usefulness of combining MS-analysis with immunogenesis prediction for identifying, ranking, and selecting peptides for therapeutic use.

Phase II study of personalized peptide vaccination for previously treated advanced colorectal cancer

The prognosis of advanced colorectal cancer (aCRC) remains poor, and development of new therapeutic approaches, including immunotherapy, is needed urgently. Herein we report on our phase II study of personalized peptide vaccination (PPV) in 60 previously treated patients with aCRC, who had failed at least one regimen of standard chemotherapy and/or targeted therapy. For PPV, a maximum of four HLA-matched peptides were individually selected from a pool of 31 different peptide candidates based on preexisting host immunity, and administered subcutaneously without severe adverse events. Boosting of IgG and cytotoxic T lymphocyte (CTL) responses specific to the administered peptides was observed in 49% and 63%, respectively, of the patients, who completed the first cycles of six vaccinations. Median overall survival (OS) time was 498 days, with 1- and 2-year survival rates of 53% and 22%, respectively. Multivariate Cox regression analysis of prevaccination factors showed that plasma IL6, IP-10, and BAFF levels were significantly prognostic for OS [hazard ratio (HR), 1.508, P = 0.043; HR, 1.579, P = 0.024; HR, 0.509, P = 0.002, respectively]. In addition, increased peptide-specific CTL responses after vaccination were significantly predictive of favorable OS (HR, 0.231; P = 0.021), suggesting a causal relationship between biologic and clinical efficacy of PPV. On the basis of the safety profile and potential clinical efficacy, we believe that clinical trials of PPV would be warranted for previously treated patients with aCRC.

Feasibility study of personalized peptide vaccination for advanced non-small cell lung cancer patients who failed two or more treatment regimens

The prognosis of non-small cell lung cancer (NSCLC) patients who failed two or more treatment regimens remains very poor. We conducted a phase II study to explore the feasibility of personalized peptide vaccination (PPV), in which peptides are selected and administered based on the pre-existing host immunity before vaccination, as a third or more line treatment in advanced NSCLC patients who failed two or more regimens. Among 57 patients enrolled, 23 or 16 patients received PPV with chemotherapy or targeted therapy, respectively, whereas 18 patients received PPV alone. A maximum of four HLA-matched peptides showing higher peptide-specific IgG responses in pre-vaccination plasma were selected from 31 pooled peptide candidates applicable for patients with HLA-A2, -A24, -A3 supertypes, and/or -A26, followed by subcutaneous administration. No severe adverse events related to PPV were observed. Median survival time was 692, 468, or 226 days in the group of PPV/chemotherapy, PPV/targeted therapy, or PPV alone, respectively. CTL responses to the vaccinated peptides became detectable after vaccination in 58, 50, or 42% of patients in each of these three groups, respectively. In contrast, peptide-specific IgG responses after vaccination augmented in 55, 75, or 62% of patients in each of these groups, respectively. These results suggest the feasibility of PPV for heavily treated advanced NSCLC patients from the view of both immunological responses and safety. Therefore, further evaluation of PPV by prospective randomized trial is warranted for a third or fourth line treatment of advanced NSCLC.

Recent progress in peptide vaccination in cancer with a focus on non-small-cell lung cancer

Active immunotherapy aimed at the stimulation of tumor-specific T cells has established itself within the clinic as a therapeutic option to treat cancer. One strategy is the use of so-called peptides that mimic genuine T-cell epitopes as vaccines to activate tumor-specific T cells. In various clinical trials, different types of vaccines, adjuvants and other immunomodulatory compounds were evaluated in patients with different types of tumors. Here, we review the trials published in the last 3 years focusing on the T-cell response, the effect of immunomodulation and potential relationships with clinical outcomes. Furthermore, we would like to make a case for the development of peptide vaccines aiming to treat non-small-cell lung cancer, the most common cause of cancer mortality.

Recent advances in immunotherapy for non-small-cell lung cancer

Despite of recent development in the field of molecular targeted therapies, lung cancer is a leading cause of cancer death in the world. Remarkable progress has been made recently in immunotherapy for patients with non-small-cell lung cancer (NSCLC), with several modalities, concepts, and treatment settings being investigated. In vaccine development, large-scale clinical trials such as those with L-BLP25, belagenpumatucel-L, TG4010, and talactoferrin are already ongoing and some results have been reported. A trial of a vaccine as adjuvant therapy for patients with completely resected NSCLC is also ongoing with one of the major cancer-testis antigens, melanoma-associated antigen (MAGE)-A3. More recently, the effectiveness of multiple peptide vaccines has also been shown. Recently developed unique treatment modalities are the immune checkpoint inhibitors, such as antibodies against PD-1 and PD-L1, which also show promise. However, although therapeutic cancer vaccines are generally thought to be safe, severe adverse events should be monitored carefully when using immune checkpoint inhibitors. Here, we discuss recent advances and future perspectives of immunotherapy for patients with NSCLC.

Juzentaihoto Failed to Augment Antigen-Specific Immunity but Prevented Deterioration of Patients' Conditions in Advanced Pancreatic Cancer under Personalized Peptide Vaccine

Juzentaihoto (JTT) is a well-known Japanese herbal medicine, which has been reported to modulate immune responses and enhance antitumor immunity in animal models. However, it is not clear whether JTT has similar effects on humans. In particular, there is little information on the effects of JTT in antigen-specific immunity in cancer patients. Here we conducted a randomized clinical study to investigate whether combined usage of JTT could affect antigen-specific immunity and clinical findings in advanced pancreatic cancer patients undergoing personalized peptide vaccination (PPV), in which HLA-matched vaccine antigens were selected based on the preexisting host immunity. Fifty-seven patients were randomly assigned to receive PPV with (n = 28) or without (n = 29) JTT. Unexpectedly, JTT did not significantly affect cellular or humoral immune responses specific to the vaccine antigens, which were determined by antigen-specific interferon-γ secretion in T cells and antigen-specific IgG titers in plasma, respectively. Nevertheless, JTT prevented deterioration of patients' conditions, such as anemia, lymphopenia, hypoalbuminemia, plasma IL-6 elevation, and reduction of performance status, which are frequently observed in advanced cancers. To our knowledge, this is the first clinical study that examined the immunological and clinical effects of JTT in cancer patients undergoing immunotherapy in humans.

Current status of immunotherapy for the treatment of biliary tract cancer

Biliary tract cancer (BTC) is one of the most aggressive malignancies. Although various promising regimens of chemotherapeutic and/or molecular targeted agents have been developed, further treatment modalities, including immunotherapies, still remain to be established for refractory patients who are unresponsive to or relapse after currently available therapeutic options for BTC. Recently, several clinical trials of immunotherapies, including peptide-based vaccines and dendritic cell (DC)-based vaccines, have been reported with promising results. Here we summarize the data from phase I or phase II clinical trials of immunotherapies for BTC. In particular, we introduce our novel immunotherapeutic approach called personalized peptide vaccine (PPV), in which HLA-matched peptides were selected and administered based on the pre-existing host immunity before vaccination, for the treatment of advanced BTC. Further clinical trials would be recommended to prove clinical benefits of these novel immunotherapeutic approaches. Recently concomitant treatments, such as chemotherapies and immune checkpoint blockade, have been reported to enhance the therapeutic effects of cancer immunotherapies through multiple coordinated immune mechanisms. Additional therapies in combination with immunotherapies could produce synergistic effects in the treatment of advanced BTC.