Cancer vaccines: should we be targeting patients with less aggressive disease?

Prospective, randomized, double-blind phase 2B trial of the TLPO and TLPLDC vaccines to prevent recurrence of resected stage III/IV melanoma: a prespecified 36-month analysis

BACKGROUND

The tumor lysate, particle-loaded, dendritic cell (TLPLDC) vaccine is made by ex vivo priming matured autologous dendritic cells (DCs) with yeast cell wall particles (YCWPs) loaded with autologous tumor lysate (TL). The tumor lysate, particle only (TLPO) vaccine uses autologous TL-loaded YCWPs coated with silicate for in vivo DC loading. Here we report the 36-month prespecified analyses of this prospective, randomized, double-blind trial investigating the ability of the TLPO and TLPLDC (±granulocyte-colony stimulating factor (G-CSF)) vaccines to prevent melanoma recurrence in high-risk patients.

METHODS

Patients with clinically disease-free stage III/IV melanoma were randomized 2:1 initially to TLPLDC versus placebo (n=124) and subsequently TLPO versus TLPLDC (n=63). All patients were randomized and blinded; however, the placebo control arm was replaced in the second randomization scheme with another novel vaccine; some analyses in this paper therefore reflect a combination of the two randomization schemes. Patients receiving the TLPLDC vaccine were further divided by their method of DC harvest (with or without G-CSF pretreatment); this was not randomized. The use of standard of care checkpoint inhibitors was not stratified between groups. Safety was assessed and Kaplan-Meier and log-rank analyses compared disease-free (DFS) and overall survival (OS).

RESULTS

After combining the two randomization processes, a total of 187 patients were allocated between treatment arms: placebo (n=41), TLPLDC (n=103), or TLPO (n=43). The allocation among arms created by the addition of patients from the two separate randomization schemes does not reflect concurrent randomization among all treatment arms. TLPLDC was further divided by use of G-CSF in DC harvest: no G-CSF (TLPLDC) (n=47) and with G-CSF (TLPLDC+G) (n=56). Median follow-up was 35.8 months. Only two patients experienced a related adverse event ≥grade 3, one each in the TLPLDC+G and placebo arms. DFS was 27.2% (placebo), 55.4% (TLPLDC), 22.9% (TLPLDC+G), and 60.9% (TLPO) (p<0.001). OS was 62.5% (placebo), 93.6% (TLPLDC), 57.7% (TLPLDC+G), and 94.6% (TLPO) (p=0.002).

CONCLUSIONS

The TLPO and TLPLDC (without G-CSF) vaccines were associated with improved DFS and OS in this clinical trial. Given production and manufacturing advantages, the efficacy of the TLPO vaccine will be confirmed in a phase 3 trial.

TRIAL REGISTRATION NUMBER

NCT02301611.

Safety and efficacy of autologous tumor lysate particle-loaded dendritic cell vaccination in combination with systemic therapies in patients with recurrent and metastatic melanoma

Immunotherapy has revolutionized the treatment of melanoma, yet survival remains poor for patients with metastatic disease. The autologous tumor lysate, particle-loaded, dendritic cell (TLPLDC) vaccine has been shown to be safe adjuvant therapy for patients with resected stage III/IV melanoma who complete the primary vaccine series. Here, we describe an open-label trial of patients with metastatic melanoma treated with TLPLDC vaccine in addition to standard of care (SoC) therapies. The TLPLDC vaccine is created by loading autologous tumor lysate into yeast cell wall particles, which are phagocytosed by autologous dendritic cells ex vivo. Patients who recurred while enrolled in a phase IIb trial of adjuvant TLPLDC vaccine (crossover cohort) and patients with measurable metastatic melanoma cohort were offered TLPLDC vaccine along with SoC therapies. Tumor response was measured by RECIST 1.1 criteria. Overall survival (OS) and progression-free survival (PFS) were estimated by intention-to-treat analysis. Fifty-four patients were enrolled (28 in crossover cohort; 26 in metastatic melanoma cohort). The vaccine was well-tolerated with no grade ≥3 adverse events when given with SoC therapies to include checkpoint inhibitors, BRAF/MEK inhibitors, tyrosine kinase inhibitors, intralesional therapy and/or radiation. In the crossover arm, OS was 76.5% and PFS was 57.1% (median follow-up of 13.9 months). In the metastatic melanoma arm, OS was 85.7% and PFS was 52.2% (median follow-up 8.5 months). The TLPLDC vaccine is well-tolerated and safe in combination with SoC therapies. Future trials will determine the efficacy of TLPLDC in combination with SoC therapies in metastatic melanoma.

T Cell Defects and Immunotherapy in Chronic Lymphocytic Leukemia

In the past few years, independent studies have highlighted the relevance of the tumor microenvironment (TME) in cancer, revealing a great variety of TME-related predictive markers, as well as identifying novel therapeutic targets in the TME. Cancer immunotherapy targets different components of the immune system and the TME at large in order to reinforce effector mechanisms or relieve inhibitory and suppressive signaling. Currently, it constitutes a clinically validated treatment for many cancers, including chronic lymphocytic leukemia (CLL), an incurable malignancy of mature B lymphocytes with great dependency on microenvironmental signals. Although immunotherapy represents a promising therapeutic option with encouraging results in CLL, the dysfunctional T cell compartment remains a major obstacle in such approaches. In the scope of this review, we outline the current immunotherapeutic treatment options in CLL in the light of recent immunogenetic and functional evidence of T cell impairment. We also highlight possible approaches for overcoming T cell defects and invigorating potent anti-tumor immune responses that would enhance the efficacy of immunotherapy.

Trial watch: Peptide vaccines in cancer therapy

Prophylactic vaccination constitutes one of the most prominent medical achievements of history. This concept was first demonstrated by the pioneer work of Edward Jenner, dating back to the late 1790s, after which an array of preparations that confer life-long protective immunity against several infectious agents has been developed. The ensuing implementation of nation-wide vaccination programs has de facto abated the incidence of dreadful diseases including rabies, typhoid, cholera and many others. Among all, the most impressive result of vaccination campaigns is surely represented by the eradication of natural smallpox infection, which was definitively certified by the WHO in 1980. The idea of employing vaccines as anticancer interventions was first theorized in the 1890s by Paul Ehrlich and William Coley. However, it soon became clear that while vaccination could be efficiently employed as a preventive measure against infectious agents, anticancer vaccines would have to (1) operate as therapeutic, rather than preventive, interventions (at least in the vast majority of settings), and (2) circumvent the fact that tumor cells often fail to elicit immune responses. During the past 30 y, along with the recognition that the immune system is not irresponsive to tumors (as it was initially thought) and that malignant cells express tumor-associated antigens whereby they can be discriminated from normal cells, considerable efforts have been dedicated to the development of anticancer vaccines. Some of these approaches, encompassing cell-based, DNA-based and purified component-based preparations, have already been shown to exert conspicuous anticancer effects in cohorts of patients affected by both hematological and solid malignancies. In this Trial Watch, we will summarize the results of recent clinical trials that have evaluated/are evaluating purified peptides or full-length proteins as therapeutic interventions against cancer.

Use of plasma ctDNA as a potential biomarker for longitudinal monitoring of a patient with metastatic high-risk upper tract urothelial carcinoma receiving pembrolizumab and personalized neoepitope-derived multipeptide vaccinations: a case report

Upper tract urothelial carcinoma (UTUC) is often diagnosed late and exhibits poor prognosis. Only limited data are available concerning therapeutic regimes and potential biomarkers for disease monitoring. Standard therapies often provide only insufficient treatment options. Hence, immunotherapies and complementary approaches, such as personalized neoepitope-derived multipeptide vaccine (PNMV), come into focus. In this context, genetic analysis of tumor tissue by whole exome sequencing represents an essential diagnostic step in order to calculate tumor mutational burden (TMB) and to reveal tumor-specific neoantigens. Furthermore, disease progression is essential to be monitored. Longitudinal screening of individually known mutations in plasma circulating tumor DNA (ctDNA) by the use of next-generation sequencing and digital droplet PCR (ddPCR) might be a promising method to fill this gap.Here, we present the case of a 55-year-old man who was diagnosed with high-risk metastatic UTUC in 2015. After initial surgery and palliative chemotherapy, he developed recurrence of the tumor. Genetic analysis revealed a high TMB of 41.2 mutations per megabase suggesting a potential success of immunotherapy. Therefore, in 2016, off-label treatment with the checkpoint-inhibitor pembrolizumab was started leading to strong regression of the disease. This therapy was then discontinued due to side effects and treatment with a previously produced PNMV was started that induced strong T cell responses. During both treatments, plasma Liquid Biopsies (pLBs) were performed to measure the number of mutated molecules per mL plasma (MM/mL) of a known tumor-specific variant in the MLH1 gene by ddPCR for longitudinal monitoring. Under treatment, MM/mL was constantly zero. A few months after all therapies had been discontinued, an increase of MM/mL was detected that persisted in the following pLBs. When MRI scans proved tumor recurrence, treatment with pembrolizumab was started again leading to a rapid decrease of MM/mL in the pLB to again zero. Treatment response was then also confirmed by MRI.This case shows that use of immunotherapy and PNMV might be a promising treatment option for patients with high-risk metastatic UTUC. Furthermore, measurement of individually known tumor mutations in plasma ctDNA by the use of pLB could be a very sensitive biomarker to longitudinally monitor disease.

AE37: a HER2-targeted vaccine for the prevention of breast cancer recurrence

INTRODUCTION

HER2 is a prevalent growth factor in a variety of malignancies, most prominently breast cancer. Over-expression has been correlated with the poorest overall survival and has been the target of successful therapies such as trastuzumab. AE37 is a novel, HER2-directed vaccine based on the AE36 hybrid peptide (aa776-790), which is derived from the intracellular portion of the HER2 protein, and the core portion of the MHC Class II invariant chain (the Ii-Key peptide). This hybrid peptide is given with GM-CSF immunoadjuvant as the AE37 vaccine.

AREAS COVERED

This article describes in detail the preclinical science leading to the creation of the AE37 vaccine and examines use of this agent in multiple clinical trials for breast and prostate cancer. The safety profile of AE37 is discussed and opinions on the potential of the vaccine in breast and prostate cancer patient subsets along with other malignancies, are offered.

EXPERT OPINION

Future trials utilizing the AE37 vaccine to treat other HER2-expressing malignancies are likely to see similar success, and this will be enhanced by combination immunotherapy. Ii-Key modification of other peptides of interest across oncology and virology could yield impressive results over the longer term.

Long-peptide vaccination with driver gene mutations in p53 and Kras induces cancer mutation-specific effector as well as regulatory T cell responses

Mutated proteins arising from somatic mutations in tumors are promising targets for cancer immunotherapy. They represent true tumor-specific antigens (TSAs) as they are exclusively expressed in tumors, reduce the risk of autoimmunity and are more likely to overcome tolerance compared to wild-type (wt) sequences. Hence, we designed a panel of long peptides (LPs, 28–35 aa) comprising driver gene mutations in TP35 and KRAS frequently found in gastrointestinal tumors to test their combined immunotherapeutic potential. We found increased numbers of T cells responsive against respective mutated and wt peptides in colorectal cancer patients that carry the tested mutations in their tumors than patients with other mutations. Further, active immunization of HLA(-A2/DR1)-humanized mice with mixes of the same mutated LPs yielded simultaneous, polyvalent CD8⁺/CD4⁺ T cell responses against the majority of peptides. Peptide-specific T cells possessed a multifunctional cytokine profile with CD4⁺ T cells showing a T_H1-like phenotype. Two mutated peptides (Kras[G12V], p53[R248W]) induced significantly higher T cell responses than corresponding wt sequences and comprised HLA-A2/DR1-restricted mutated epitopes. However, vaccination with the same highly immunogenic LPs strongly increased systemic regulatory T cells (T_reg) numbers in a syngeneic sarcoma model over-expressing these mutated protein variants and resulted in accelerated tumor outgrowth. In contrast, tumor outgrowth was delayed when vaccination was directed against tumor-intrinsic Kras/Tp53 mutations of lower immunogenicity. Conclusively, we show that LP vaccination targeting multiple mutated TSAs elicits polyvalent, multifunctional, and mutation-specific effector T cells capable of targeting tumors. However, the success of this therapeutic approach can be hampered by vaccination-induced, TSA-specific T_regs.

Phase Ib trial of folate binding protein (FBP)-derived peptide vaccines, E39 and an attenuated version, E39': An analysis of safety and immune response

In this randomized phase Ib trial, we tested combining the E39 peptide vaccine with a vaccine created from E39', an attenuated version of E39. Patients with breast or ovarian cancer, who were disease-free after standard of care therapy, were enrolled and randomized to one of three arms. Arm EE received six E39 inoculations; arm EE' received three E39 inoculations followed by three E39'; and arm E'E received three E39' inoculations, followed by three E39. Within each arm, the first five patients received 500 μg of peptide and the remainder received 1000 μg. Patients were followed for toxicity, and immune responses were measured. This initial analysis after completion of the primary vaccination series has confirmed the safety of both vaccines. Immune analyses suggest incorporating the attenuated version of the peptide improves immune responses and that sequencing of E39 followed by E39' might produce the optimal immune response.

TRIAL REGISTRATION

NCT02019524.

Arming the Immune System Through Vaccination to Prevent Cancer Recurrence

Cancer vaccines have the potential to provide a nontoxic treatment for the prevention of cancer recurrence in the adjuvant setting. Many cancer vaccines have been tested in multiple phase III trials with minimal success. However, through these failed clinical trials, we have learned that the ideal setting for vaccine therapy is the adjuvant setting. Also, we have learned important lessons about patient selection to maximize the probability of success. This article will highlight some of the successes, our trial results in the adjuvant setting, and future directions.

Gaining ground on a cure through synergy: combining checkpoint inhibitors with cancer vaccines

INTRODUCTION

The approval of multiple checkpoint inhibitors (CPIs) for the treatment of advanced malignancies has sparked an explosion of research in the field of cancer immunotherapy. Despite the success of these medications, a large number of patients with advanced malignancy do not benefit from therapy. Early research indicates that a therapeutic combination of cancer vaccines with checkpoint inhibitors may lead to synergistic effects and higher response rates than monotherapy. Areas covered: This paper summarizes the previously completed and ongoing research on this exciting combination, including the use of the tumor lysate, particle-loaded dendritic cell (TLPLDC) vaccine combined with checkpoint inhibitors in advanced melanoma. Expert commentary: Increasing experience with CPIs has led to improved understanding of which patients may benefit and it is increasingly clear that the presence of a pre-existing immune response to the tumor, along with tumor-infiltrating lymphocytes, is key to the success of CPIs. One exciting possibility for the future is the addition of a cancer vaccine to CPI therapy, eliciting these crucial T cells, which can then be augmented and protected by the CPI. A number of current and future studies are addressing this very exciting combination therapy.

Clinical Development of the E75 Vaccine in Breast Cancer

E75 is an immunogenic peptide derived from the human epidermal growth factor receptor 2 (HER2) protein. A large amount of preclinical work evaluated the immunogenicity of E75, after which phase I trials investigated using E75 mixed with an immunoadjuvant as a vaccine. Those studies showed the vaccine to be safe and capable of stimulating an antigen-specific immune response. Subsequent to that, our group conducted trials evaluating E75 + granulocyte macrophage colony-stimulating factor (GM-CSF) in the adjuvant setting. The studies enrolled node-positive and high-risk node-negative breast cancer patients, with the goal being to determine if vaccination could decrease the recurrence risk. The studies included 187 evaluable patients: 108 vaccinated ones and 79 controls. The 5-year disease-free survival for the vaccinated patients was 89.7% compared to 80.2% for the control patients, a 48% reduction in relative risk of recurrence. Based on these data, E75 + GM-CSF, now known as NeuVax™, is being evaluated in a phase III trial. In this article, we review preclinical data and results of the early-phase trials and provide an update on the ongoing phase III study. We also present additional strategies for employing the vaccine to be included as a component of combination immunotherapy as well as in the setting of ductal carcinoma in situ as an initial step towards primary prevention.

Peptide-Based Cancer Vaccine Strategies and Clinical Results

Active cancer immunotherapy is an exciting and developing field in oncology research. Peptide vaccines, the use of isolated immunogenic tumor-associated antigen (TAA) epitopes to generate an anticancer immune response, are an attractive option as they are easily produced and administered with minimal toxicity. Multiple TAA-derived peptides have been identified and evaluated with various vaccine strategies currently in clinical testing. Research suggests that utilizing vaccines in patients with minimal-residual disease may be a more effective strategy compared to targeting patients with widely metastatic disease as it avoids the immune suppression and tolerance associated with higher volumes of more established disease. Clinical trials also suggest that vaccines may need to be tailored and administered to specific cancer subtypes to achieve maximum efficacy. Additionally, numerous immunomodulators now in research and development show potential synergy with peptide vaccines. Our group has focused on a simpler, single-peptide strategy largely from the HER2/neu protein. We will discuss our experience thus far as well as review other peptide vaccine strategies that have shown clinical efficacy.

Critical issues in cancer vaccine trial design

As the clinical experience with cancer vaccines and cancer immunotherapy increases, there are important lessons that can be learned from the successes and failures of past trials. Many lessons affect the design and conduct of clinical trials themselves. Appropriate patient selection, clinical trial design, immunologic monitoring, and appropriate endpoints are all essential to the efficiency and success of bringing cancer vaccines from conception to clinical use.

Personalized approaches to active immunotherapy in cancer

Immunotherapy is emerging as a promising anti-cancer curative modality. However, in contrast to recent advances obtained employing checkpoint blockade agents and T cell therapies, clinical efficacy of therapeutic cancer vaccines is still limited. Most vaccination attempts in the clinic represent "off-the shelf" approaches since they target common "self" tumor antigens, shared among different patients. In contrast, personalized approaches of vaccination are tailor-made for each patient and in spite being laborious, hold great potential. Recent technical advancement enabled the first steps in the clinic of personalized vaccines that target patient-specific mutated neo-antigens. Such vaccines could induce enhanced tumor-specific immune response since neo-antigens are mutation-derived antigens that can be recognized by high affinity T cells, not limited by central tolerance. Alternatively, the use of personalized vaccines based on whole autologous tumor cells, overcome the need for the identification of specific tumor antigens. Whole autologous tumor cells could be administered alone, pulsed on dendritic cells as lysate, DNA, RNA or delivered to dendritic cells in-vivo through encapsulation in nanoparticle vehicles. Such vaccines may provide a source for the full repertoire of the patient-specific tumor antigens, including its private neo-antigens. Furthermore, combining next-generation personalized vaccination with other immunotherapy modalities might be the key for achieving significant therapeutic outcome.

Therapeutic vaccines for cancer: an overview of clinical trials

The therapeutic potential of host-specific and tumour-specific immune responses is well recognized and, after many years, active immunotherapies directed at inducing or augmenting these responses are entering clinical practice. Antitumour immunization is a complex, multi-component task, and the optimal combinations of antigens, adjuvants, delivery vehicles and routes of administration are not yet identified. Active immunotherapy must also address the immunosuppressive and tolerogenic mechanisms deployed by tumours. This Review provides an overview of new results from clinical studies of therapeutic cancer vaccines directed against tumour-associated antigens and discusses their implications for the use of active immunotherapy.

Telomerase (GV1001) vaccination together with gemcitabine in advanced pancreatic cancer patients

Telomerase is expressed in 85-90 % of pancreatic adenocarcinomas and might be a target for active cancer immunotherapy. A study was conducted to investigate safety and immunogenicity in non-resectable pancreatic carcinoma patients using a 16-amino acid telomerase peptide (GV1001) for vaccination in combination with GM-CSF and gemcitabine as first line treatment. Three different vaccine treatment schedules were used; [A (n=6), B (n=6) and C (n=5)]. Groups A/B received GV1001, GM-CSF and gemcitabine concurrently. Group C received initially GV1001 and GM-CSF while gemcitabine was added at disease progression. Group D (n=4) was treated with gemcitabine alone. Adverse events (AE) related to vaccination were mild (grades I-II). Grade III AEs were few and transient. An induced GV 1001‑specific immune response was defined as an increase ≥2 above the baseline value in one of the assays (DTH, proliferation, ELISPOT and cytokine secretion assays, respectively). A telomerase‑specific immune response was noted in 4/6 patients in group A, 4/6 patients in group B and 2/5 patients in group C. An induced ras‑specific immune response (antigenic spreading) was seen in 5 of the 17 patients. The cytokine pattern was that of a Th1-like profile. A treatment induced telomerase or ras response was also noted in group D. All responses were weak and transient. A significant decrease in regulatory T-cells over time was noted in patients in groups A and B (p<0.05). Telomerase vaccination (GV1001) in combination with chemotherapy appeared to be safe but the immune responses were weak and transient. Measures have to be taken to optimize immune responses of GV1001 for it to be considered of clinical interest.

Trial Watch: Peptide vaccines in cancer therapy

Throughout the past 3 decades, along with the recognition that the immune system not only influences oncogenesis and tumor progression, but also determines how established neoplastic lesions respond therapy, renovated enthusiasm has gathered around the possibility of using vaccines as anticancer agents. Such an enthusiasm quickly tempered when it became clear that anticancer vaccines would have to be devised as therapeutic, rather than prophylactic, measures, and that malignant cells often fail to elicit (or actively suppress) innate and adaptive immune responses. Nonetheless, accumulating evidence indicates that a variety of anticancer vaccines, including cell-based, DNA-based, and purified component-based preparations, are capable of circumventing the poorly immunogenic and highly immunosuppressive nature of most tumors and elicit (at least under some circumstances) therapeutically relevant immune responses. Great efforts are currently being devoted to the identification of strategies that may provide anticancer vaccines with the capacity of breaking immunological tolerance and eliciting tumor-associated antigen-specific immunity in a majority of patients. In this sense, promising results have been obtained by combining anticancer vaccines with a relatively varied panels of adjuvants, including multiple immunostimulatory cytokines, Toll-like receptor agonists as well as inhibitors of immune checkpoints. One year ago, in the December issue of OncoImmunology, we discussed the biological mechanisms that underlie the antineoplastic effects of peptide-based vaccines and presented an abundant literature demonstrating the prominent clinical potential of such an approach. Here, we review the latest developments in this exciting area of research, focusing on high-profile studies that have been published during the last 13 mo and clinical trials launched in the same period to evaluate purified peptides or full-length proteins as therapeutic anticancer agents.

Prostate cancer vaccines

In 2010, the US FDA approved the first therapeutic cancer vaccine for the treatment of castration refractory prostate cancer - sipuleucel-T. Prostate cancer is an ideal model for cancer vaccine development based on the ready demonstration of humoral and cellular immunity to a range of cancer antigens as well as often slow progression which means that patients who are otherwise well may have a radiologically evaluable minor progression, after conventional treatment and can undergo vaccine therapy over sufficient periods of time, so as to allow the generation of a robust antitumor response. The association of prostate cancer with one of the few serum cancer biomarkers in general use has also allowed assessment of response and risk stratification of patients. In this review, we will examine key aspects of the evolution of prostate cancer vaccines, which provides an accurate prototype for other cancers, and the challenges we face.

Nanomaterials in the application of tumor vaccines: advantages and disadvantages

Tumor vaccines are a novel approach to the treatment of malignancy, and are attracting the attention of the medical profession. Nanomaterials have significant advantages in the preparation of a tumor vaccine, including their ability to penetrate and target cancer tissue and their antigenic properties. In this review, we focus on several nanomaterials, ie, carbon nanotubes, nanoemulsions, nanosized aluminum, and nanochitosan. Applications for these nanomaterials in nanovaccines and their biological characteristics, as well as their potential toxicity, are discussed.

Tracking and evaluation of dendritic cell migration by cellular magnetic resonance imaging

Cellular magnetic resonance imaging (MRI) is a means by which cells labeled ex vivo with a contrast agent can be detected and tracked over time in vivo. This technology provides a noninvasive method with which to assess cell-based therapies in vivo. Dendritic cell (DC)-based vaccines are a promising cancer immunotherapy, but its success is highly dependent on the injected DC migrating to a secondary lymphoid organ such as a nearby lymph node. There the DC can interact with T cells to elicit a tumor-specific immune response. It is important to verify DC migration in vivo using a noninvasive imaging modality, such as cellular MRI, so that important information regarding the anatomical location and persistence of the injected DC in a targeted lymph node can be provided. An understanding of DC biology is critical in ascertaining how to label DC with sufficient contrast agent to render them detectable by MRI. While iron oxide nanoparticles provide the best sensitivity for detection of DC in vivo, a clinical grade iron oxide agent is not currently available. A clinical grade (19) Fluorine-based perfluorcarbon nanoemulsion is available but is less sensitive, and its utility to detect DC migration in humans remains to be demonstrated using clinical scanners presently available. The ability to quantitatively track DC migration in vivo can provide important information as to whether different DC maturation and activation protocols result in improved DC migration efficiency which will determine the vaccine's immunogenicity and ultimately the tumor immunotherapy's outcome in humans.

Therapeutic vaccines: the ultimate personalized therapy?

Personalized therapy is directed at obtaining maximal therapeutic effect on diseased tissue with minimal off-target side effects. Many classes of therapeutics have attempted to reach this ideal, only to fall well short. Therapeutic vaccines represent a novel class of therapies that can induce a dynamic immune response that, in theory, can continue to adapt and expand following initiation of vaccination. This adaptability, through epitope spreading or antigen cascade, can continuously refine a therapeutic immune response, making it more relevant to the patient's tumor. This active, dynamic, iterative process can continue long after the vaccine course has been completed. Recent clinical trials have provided further insight into the clinical activity of therapeutic vaccines, and offer guidance on clinical expectations following vaccine. The ongoing active sculpting of the immune response, along with the lack of significant side effects, uniquely positions therapeutic vaccines as perhaps the ultimate in personalized therapy.