Durable and dynamic hTERT immune responses following vaccination with the long-peptide cancer vaccine UV1: long-term follow-up of three phase I clinical trials

Unlocking Immunity: Innovative prostate cancer vaccine strategies

OBJECTIVE

Prostate Cancer (PCa) is a leading cause of cancer-related mortality in men, especially in Western societies. The objective of this research is to address the unmet need for effective treatments in advanced or recurrent PCa, where current strategies fall short of offering a cure. The focus is on leveraging immunotherapy and cancer vaccines to target the tumor's unique immunological microenvironment.

MAIN RESULTS

Despite immunotherapy's success in other cancers, its effectiveness in PCa has been limited by the tumor's immunosuppressive characteristics. However, cancer vaccines that engage Tumor-Specific Antigens (TSA) and Tumor-Associated Antigens (TAA) have emerged as a promising approach. Preclinical and clinical investigations of Dendritic Cell (DC) vaccines, DNA vaccines, mRNA vaccines, peptide vaccines, and viral vectors have shown their potential to elicit anti-tumor immune responses. The exploration of combination therapies with immune checkpoint inhibitors and the advent of novel adjuvants and oral microparticle vaccines present innovative strategies to improve efficacy and compliance.

CONCLUSION

The development of cancer vaccines for PCa holds significant potential. Future directions include optimizing vaccine design, refining combination therapy strategies, and creating patient-friendly administration methods. The integration of interdisciplinary knowledge and innovative clinical trial designs is essential for advancing personalized and precision immunotherapy for PCa.

Mannan-Decorated Lipid Calcium Phosphate Nanoparticle Vaccine Increased the Antitumor Immune Response by Modulating the Tumor Microenvironment

With the rapid development of tumor immunotherapy, nanoparticle vaccines have attracted much attention as potential therapeutic strategies. A systematic review and analysis must be carried out to investigate the effect of mannose modification on the immune response to nanoparticles in regulating the tumor microenvironment, as well as to explore its potential clinical application in tumor therapy. Despite the potential advantages of nanoparticle vaccines in immunotherapy, achieving an effective immune response in the tumor microenvironment remains a challenge. Tumor immune escape and the overexpression of immunosuppressive factors limit its clinical application. Therefore, our review explored how to intervene in the immunosuppressive mechanism in the tumor microenvironment through the use of mannan-decorated lipid calcium phosphate nanoparticle vaccines to improve the efficacy of immunotherapy in patients with tumors and to provide new ideas and strategies for the field of tumor therapy.

Clinical research progress of telomerase targeted cancer immunotherapy: a literature review

Background and Objective

Telomerase is activated or overexpressed in 85-90% of tumors, which maintains the length of telomere and has become an important anti-cancer target. Increasing clinical and preclinical data suggest that telomerase-targeted cancer immunotherapy could achieve effective killing of tumor cells in vivo. This article reviews the research progress of telomerase targeted cancer immunotherapy in clinical and pre-clinical trials, aiming to provide a reference for further clinical research and treatment of cancers.

Methods

We investigated the research progress of telomerase immunotherapy in the last 20 years from four electronic databases.

Key Content and Findings

Telomerase-targeted immunotherapies have been developed with the arising of a new era in immuno-oncology, including peptide vaccines, DNA vaccines, dendritic cells (DCs), adoptive cell transfer (ACT) therapies, antibodies, etc. Some of them have been approved for undergoing clinical trials by the Food and Drug Administration (FDA) for the treatment of various cancers, such as pancreatic cancer, non-small cell lung cancer, melanoma, leukaemia. Of all the treatment modalities, vaccines are the primary treatment methods, some of which have been even entered into phase III clinical trials. The main clinical application direction of telomerase vaccine is the combination with other drugs and treatment modalities, including combination with other vaccines targeting human telomerase reverse transcriptase (hTERT), traditional chemotherapy drugs and immunosuppressors. We also summarized the recent findings of immunotherapy targeting hTERT, focusing on various vaccines and the current status of associated clinical trials. We further discussed the advantages, disadvantages and potential developmental directions of various telomerase-targeted immunotherapies.

Conclusions

Telomerase-targeted cancer immunotherapy has promising prospects in improving patient survival expectancy. This review may provide data support and design ideas for all researchers and pharmaceutical enterprises in this field.

Tolerability and efficacy of the cancer vaccine UV1 in patients with recurrent or metastatic PD-L1 positive head and neck squamous cell carcinoma planned for first-line treatment with pembrolizumab - the randomized phase 2 FOCUS trial

Background

Globally, head and neck squamous cell carcinoma (HNSCC) is the seventh most common malignancy. Despite aggressive multimodal treatment approaches, recurrent and/or metastatic (R/M) disease develops in >50% of patients. In this setting, pembrolizumab was approved for patients with PD-L1 expression. However, response rates with checkpoint inhibitor monotherapy remain limited and strategies to strengthen tumor-directed immune responses are needed.

Objective

The FOCUS trial is designed to estimate the effectiveness of UV1 vaccination in combination with pembrolizumab versus pembrolizumab as a single agent in patients with R/M HNSCC.

Methods and analysis

The FOCUS trial is a two-armed, randomized, multicenter phase II study which was designed to evaluate the efficacy and feasibility of the hTERT-targeted cancer vaccine UV1 as add-on to pembrolizumab in the 1st line treatment of patients with R/M PD-L1 positive (combined positive score ≥1) HNSCC. Secondary objectives are the exploration of patient subgroups most likely deriving benefit from this novel combination and the establishment of liquid biopsy tumor monitoring in HNSCC.

Ethics and dissemination

This clinical study was designed and will be conducted in compliance with Good Clinical Practice and in accordance with the Declaration of Helsinki. It is intended to publish the results of this study in peer-reviewed scientific journals and to present its content at academic conferences.

Conclusions

A significant number of patients with R/M HNSCC are frail and may not tolerate chemotherapy, these patients may only be suitable for pembrolizumab monotherapy. However, long term disease stabilizations remain the exception and there is a need for the development of efficacious combination regimens for this patient population. The FOCUS study aims to optimize treatment of R/M HNSCC patients with this promising new treatment approach.

Clinical Trial Registration

https://clinicaltrials.gov/study/NCT05075122, identifier NCT05075122.

A novel risk score system based on immune subtypes for identifying optimal mRNA vaccination population in hepatocellular carcinoma

PURPOSE

Although mRNA vaccines have shown certain clinical benefits in multiple malignancies, their therapeutic efficacies against hepatocellular carcinoma (HCC) remains uncertain. This study focused on establishing a novel risk score system based on immune subtypes so as to identify optimal HCC mRNA vaccination population.

METHODS

GEPIA, cBioPortal and TIMER databases were utilized to identify candidate genes for mRNA vaccination in HCC. Subsequently, immune subtypes were constructed based on the candidate genes. According to the differential expressed genes among various immune subtypes, a risk score system was established using machine learning algorithm. Besides, multi-color immunofluorescence of tumor tissues from 72 HCC patients were applied to validate the feasibility and efficiency of the risk score system.

RESULTS

Twelve overexpressed and mutated genes associated with poor survival and APCs infiltration were identified as potential candidate targets for mRNA vaccination. Three immune subtypes (e.g. IS1, IS2 and IS3) with distinct clinicopathological and molecular profiles were constructed according to the 12 candidate genes. Based on the immune subtype, a risk score system was developed, and according to the risk score from low to high, HCC patients were classified into four subgroups on average (e.g. RS1, RS2, RS3 and RS4). RS4 mainly overlapped with IS3, RS1 with IS2, and RS2+RS3 with IS1. ROC analysis also suggested the significant capacity of the risk score to distinguish between the three immune subtypes. Higher risk score exhibited robustly predictive ability for worse survival, which was further independently proved by multi-color immunofluorescence of HCC samples. Notably, RS4 tumors exhibited an increased immunosuppressive phenotype, higher expression of the twelve potential candidate targets and increased genome altered fraction, and therefore might benefit more from vaccination.

CONCLUSIONS

This novel risk score system based on immune subtypes enabled the identification of RS4 tumor that, due to its highly immunosuppressive microenvironment, may benefit from HCC mRNA vaccination.

Bridging responses to a human telomerase reverse transcriptase-based peptide cancer vaccine candidate in a mechanism-based model

Therapeutic cancer vaccines are novel immuno-therapeutics, aiming to improve clinical outcomes with other immunotherapies. However, obstacles to their successful clinical development remain, which model-informed drug development approaches may address. UV1 is a telomerase based therapeutic cancer vaccine candidate being investigated in phase I clinical trials for multiple indications. We developed a mechanism-based model structure, using a nonlinear mixed-effects modeling techniques, based on longitudinal tumor sizes (sum of the longest diameters, SLD), UV1-specific immunological assessment (stimulation index, SI) and overall survival (OS) data obtained from a UV1 phase I trial including non-small cell lung cancer (NSCLC) patients and a phase I/IIa trial including malignant melanoma (MM) patients. The final structure comprised a mechanistic tumor growth dynamics (TGD) model, a model describing the probability of observing a UV1-specific immune response (SI ≥ 3) and a time-to-event model for OS. The mechanistic TGD model accounted for the interplay between the vaccine peptides, immune system and tumor. The model-predicted UV1-specific effector CD4+ T cells induced tumor shrinkage with half-lives of 103 and 154 days in NSCLC and MM patients, respectively. The probability of observing a UV1-specific immune response was mainly driven by the model-predicted UV1-specific effector and memory CD4+ T cells. A high baseline SLD and a high relative increase from nadir were identified as main predictors for a reduced OS in NSCLC and MM patients, respectively. Our model predictions highlighted that additional maintenance doses, i.e. UV1 administration for longer periods, may result in more sustained tumor size shrinkage.

Advances, opportunities and challenges in developing therapeutic cancer vaccines

Therapeutic cancer vaccines have shown promising efficacy in helping immunotherapy for cancer patients, but the systematic characterization of the clinical application and the method for improving efficacy is lacking. Here, we mainly summarize the classification of therapeutic cancer vaccines, including protein vaccines, nucleic acid vaccines, cellular vaccines and anti-idiotypic antibody vaccines, and subdivide the above vaccines according to different types and delivery forms. Additionally, we outline the clinical efficacy and safety of vaccines, as well as the combination strategies of therapeutic cancer vaccines with other therapies. This review will provide a detailed overview and rationale for the future clinical application and development of therapeutic cancer vaccines.

TERT promoter mutations and gene amplification in endometrial cancer

OBJECTIVE

To assess the clinicopathologic, molecular profiles, and survival outcomes of patients with endometrial carcinomas (ECs) harboring telomerase reverse transcriptase (TERT) hotspot mutations or gene amplification.

METHODS

ECs harboring somatic TERT promoter hotspot mutations or gene amplification (TERT-altered) were identified from 1944 ECs that underwent clinical tumor-normal sequencing from 08/2016-12/2021. Clinicopathologic variables, somatic mutation profiles, and survival outcomes of TERT-alt and TERT-wild-type EC were assessed.

RESULTS

We identified 66 TERT-altered ECs (43 TERT-mutated and 23 TERT-amplified), representing 3% of the unselected ECs across histologic subtypes. Most TERT-altered ECs were of copy number (CN)-high/TP53abn molecular subtype (n = 40, 60%), followed by microsatellite-unstable (MSI-H) or CN-low/no specific molecular profile (NSMP)(n = 13, 20% each). TERT-amplified and TERT-mutated ECs were molecularly distinct, with TERT-amplified ECs being more genomically instable and more frequently harboring TP53 and PPP2R1A alterations (q < 0.1). Compared to TERT-wild-type ECs, TERT-altered ECs were more commonly of CN-H/TP53abn molecular subtype (31% vs 57%, p = 0.001), serous histology (10% vs 26%, p = 0.004), and were significantly enriched for TP53, CDKN2A/B, and DROSHA somatic genetic alterations (q < 0.1). Median progression-free survival was 18.7 months (95% CI 11.8-not estimable [NE]) for patients with TERT-altered EC and 80.9 months (65.8-NE) for patients with TERT-wild-type EC (HR 0.33, 95% CI 0.21-0.51, p < 0.001). Similarly, median overall survival was 46.7 months (95% CI 30-NE) for TERT-altered EC patients and not reached for TERT-wild-type EC patients (HR 0.24, 95% CI 0.13-0.44, p < 0.001).

CONCLUSION

TERT-altered ECs, although rare, are enriched for CN-high/TP53abn tumors, TP53, CDKN2A/B and DROSHA somatic mutations, and independently predict worse survival outcomes.

Monophosphoryl lipid A-assembled nanovaccines enhance tumor immunotherapy

Therapeutic cancer nanovaccines can induce strong antitumor immunity and establish long-term immune memory and have shown potential for curing tumors in some clinical trials. However, weak immunogenicity and safety concerns of nanocarriers limit the clinical translation of some therapeutic nanovaccines. Here, we developed minimal-component cancer nanovaccines, monophosphoryl lipid A (MPLA)-assembled nanovaccines (MANs), that could facilitate the clinical application of nanovaccines. The MANs were formed by protein antigens extracted from chemotherapy-induced tumor cell cultures and the amphiphilic immune adjuvant MPLA. Compared with free chemotherapy-induced antigens, MANs can activate the Toll-like receptor 4 (TLR4)-mediated signalling pathway and promote adaptive immunity against tumor antigens. Mechanistic analysis indicated that MANs induced antigen capture of DCs and promoted the activation of DCs and T cells, thereby optimizing the ratio of CD8+ T/Tregs in tumors and facilitating the transformation of the tumor immune microenvironment (TIME) from "cold" to "hot". In a CT26 colorectal cancer model, MANs+αPD-1 significantly improved the efficacy of αPD-1 treatment. Our work offers a strategy for designing minimal-component cancer nanovaccines with potential clinical benefits. STATEMENT OF SIGNIFICANCE: To address the weak immunogenicity of cancer vaccines and the safety concerns of nanocarriers, we prepared MPLA-assembled nanovaccines (MANs) using chemotherapy induced antigens and the immune adjuvant MPLA to promote cancer vaccines to clinical practice. MANs effectively internalized tumor antigens and induced DC maturation, indicating that the initial anti-tumor response had been activated. MANs+αPD-1 induced APCs, CD8+ T cells and memory T cells with positive anti-tumor effects to migrate to tumor tissue, thus leading to the transformation of the tumor immune microenvironment from "cold" to "hot". At the animal level, the combination of MANs and αPD-1 exerted synergistic effects and significantly enhanced tumor immunotherapy. Therefore, the treatment regimen of MANs+αPD-1 has potential clinical benefits.

The screening, identification, design and clinical application of tumor-specific neoantigens for TCR-T cells

Recent advances in neoantigen research have accelerated the development of tumor immunotherapies, including adoptive cell therapies (ACTs), cancer vaccines and antibody-based therapies, particularly for solid tumors. With the development of next-generation sequencing and bioinformatics technology, the rapid identification and prediction of tumor-specific antigens (TSAs) has become possible. Compared with tumor-associated antigens (TAAs), highly immunogenic TSAs provide new targets for personalized tumor immunotherapy and can be used as prospective indicators for predicting tumor patient survival, prognosis, and immune checkpoint blockade response. Here, the identification and characterization of neoantigens and the clinical application of neoantigen-based TCR-T immunotherapy strategies are summarized, and the current status, inherent challenges, and clinical translational potential of these strategies are discussed.

Clinical Activity of Combined Telomerase Vaccination and Pembrolizumab in Advanced Melanoma: Results from a Phase I Trial

PURPOSE

Cancer vaccines represent a novel treatment modality with a complementary mode of action addressing a crucial bottleneck for checkpoint inhibitor (CPI) efficacy. CPIs are expected to release brakes in T-cell responses elicited by vaccination, leading to more robust immune responses. Increased antitumor T-cell responses may confer increased antitumor activity in patients with less immunogenic tumors, a subgroup expected to achieve reduced benefit from CPIs alone. In this trial, a telomerase-based vaccine was combined with pembrolizumab to assess the safety and clinical activity in patients with melanoma.

PATIENTS AND METHODS

Thirty treatment-naïve patients with advanced melanoma were enrolled. Patients received intradermal injections of UV1 with adjuvant GM-CSF at two dose levels, and pembrolizumab according to the label. Blood samples were assessed for vaccine-induced T-cell responses, and tumor tissues were collected for translational analyses. The primary endpoint was safety, with secondary objectives including progression-free survival (PFS), overall survival (OS), and objective response rate (ORR).

RESULTS

The combination was considered safe and well-tolerated. Grade 3 adverse events were observed in 20% of patients, with no grade 4 or 5 adverse events reported. Vaccination-related adverse events were mostly mild injection site reactions. The median PFS was 18.9 months, and the 1- and 2-year OS rates were 86.7% and 73.3%, respectively. The ORR was 56.7%, with 33.3% achieving complete responses. Vaccine-induced immune responses were observed in evaluable patients, and inflammatory changes were detected in posttreatment biopsies.

CONCLUSIONS

Encouraging safety and preliminary efficacy were observed. Randomized phase II trials are currently ongoing.

Impact of human telomerase reverse transcriptase peptide vaccine combined with androgen deprivation therapy and radiotherapy in de novo metastatic prostate cancer: Long-term clinical monitoring

Prostate cancer is considered as poorly immunogenic. In a phase I/II study on de novo metastatic prostate cancer we found that a human telomerase reverse transcriptase (hTERT) vaccine induced an early immune response in most of the patients. Here we present the results from the long-term monitoring of the immune responses and clinical outcomes. Twenty-two men with ISUP 4 to 5 and lymph node and/or bone metastases were treated with androgen deprivation therapy (ADT), radiotherapy and the hTERT vaccine UV1 between January 2013 and July 2014. Immune response was monitored before, during and after vaccination and continued every 6 months until PSA progression. All patients had magnetic resonance imaging (MRI) at baseline, and after 6 months, 1 and 2 years, and at progression. The clinical outcome was time to progression, overall survival and prostate cancer-specific survival. The median follow-up was 62 months (range: 19-101). At the last observation, nine of the 22 patients were still alive. Six have no progression, two have castration-resistant disease treated with second-line ADT and one has castration-refractory disease. Median time to PSA progression was 21 months, median overall survival was 62 months and median prostate cancer-specific survival was 84 months. Lack of immune response was an independent marker of prostate cancer death. The long-term monitoring showed that some patients had unanticipated subsequent high immune responses without developing recurrence. This association indicates that there might be a clinical benefit of hTERT vaccination in a subgroup of men with primary metastatic hormone-sensitive prostate cancer treated with ADT and radiotherapy.

Therapeutic cancer vaccination against telomerase: clinical developments in melanoma

PURPOSE OF REVIEW

Checkpoint inhibitors (CPIs) have revolutionized treatment outcomes for patients with malignant melanoma. Long-term follow-up shows that a substantial subset of patients who exhibit clinical responses achieve extended overall survival. Nevertheless, most patients do not achieve durable benefit from CPIs, and improvements are urgently needed. The clinical efficacy of CPIs depends on highly variable preexisting spontaneous T-cell immune responses. Cancer vaccines represent an independent treatment modality uniquely capable of expanding the repertoire of tumor-specific T cells in cancer patients and thus have the capacity to compensate for the variability in spontaneous T-cell responses. Vaccines are, therefore, considered attractive components in a CPI-combination strategy.

RECENT FINDINGS

Here we discuss recent results obtained through therapeutic vaccination against telomerase human telomerase reverse transcriptase (hTERT). Recent publications on translational research and clinical results from phase I trials indicate that vaccination against telomerase in combination with CPIs provides relevant immune responses, negligible added toxicity, and signals of clinical efficacy.

CONCLUSION

In the near future, randomized data from clinical trials involving therapeutic cancer vaccines and checkpoint inhibitors will be available. Positive readout may spark broad development and allow cancer vaccines to find their place in the clinic as an important component in multiple future CPI combinations.

Incorporation of a TGF-β2-inhibiting oligodeoxynucleotide molecular adjuvant into a tumor cell lysate vaccine to enhance antiglioma immunity in mice

Introduction

Transforming growth factor β2 (TGF-β2), also known as glioma-derived T-cell suppressor factor, is associated with the impairment of tumor immune surveillance. Therefore, blocking TGF-β2 signaling probably be a feasible strategy to develop a novel type of adjuvant for glioma vaccines to enhance antitumor immunity.

Methods

A TGF-β2 inhibitory oligodeoxynucleotide, TIO3, was designed with sequences complementary to the 3' untranslated region of TGF-β2 mRNA. The expression of TGF-β2 and MHC-I was detected by qPCR, western and flow cytometry in vitro. All the percentage and activation of immune cells were detected by flow cytometry. Subsequently, TIO3 was formulated with Glioma cell lysate (TCL) and investigated for its antitumor effects in GL261 murine glioma prophylactic and therapeutic models.

Results

TIO3 could efficiently downregulate the expression of TGF-β2 while increase the MHC-I's expression in GL261 and U251 glioma cells in vitro. Meanwhile, TIO3 was detected in mice CD4+ T, CD8+ T, B and Ly6G+ cells from lymph nodes after 24 hours incubation. Moreover, TCL+TIO3 vaccination significantly prolonged the survival of primary glioma-bearing mice and protected these mice from glioma re-challenge in vivo. Mechanistically, TCL+TIO3 formulation strongly evoke the antitumor immune responses. 1) TCL+TIO3 significantly increased the composition of CD4+ and CD8+ T cells from draining lymph nodes while promoted their IFN-γ production and reduced the expression of TGF-β2 and PD1. 2) TCL+TIO3 activated the NK cells with the elevation of CD69 or NKG2D expression and PD1 reduction. 3) TCL+TIO3 increased the glioma-specific lysis CTLs from spleen. 4) TCL+TIO3 downregulated PD-L1 expression in glioma tissues and in Ly6G+ cells among glioma-infiltrating immune cells.

Conclusion

TIO3 is a promising adjuvant for enhancing TCL-based vaccines to produce a more vigorous and long-lasting antitumor response by interfering with TGF-β2 expression.

TERT promoter mutations and methylation for telomerase activation in urothelial carcinomas: New mechanistic insights and clinical significance

Telomerase, an RNA-dependent DNA polymerase synthesizing telomeric TTAGGG sequences, is primarily silent in normal human urothelial cells (NHUCs), but widely activated in urothelial cell-derived carcinomas or urothelial carcinomas (UCs) including UC of the bladder (UCB) and upper track UC (UTUC). Telomerase activation for telomere maintenance is required for the UC development and progression, and the key underlying mechanism is the transcriptional de-repression of the telomerase reverse transcriptase (TERT), a gene encoding the rate-limiting, telomerase catalytic component. Recent mechanistic explorations have revealed important roles for TERT promoter mutations and aberrant methylation in activation of TERT transcription and telomerase in UCs. Moreover, these TERT-featured genomic and epigenetic alterations have been evaluated for their usefulness in non-invasive UC diagnostics, recurrence monitoring, outcome prediction and response to treatments such as immunotherapy. Importantly, the detection of the mutated TERT promoter and TERT mRNA as urinary biomarkers holds great promise for urine-based UC liquid biopsy. In the present article, we review recent mechanistic insights into altered TERT promoter-mediated telomerase activation in UCs and discuss potential clinical implications. Specifically, we compare differences in senescence and transformation between NHUCs and other types of epithelial cells, address the interaction between TERT promoter mutations and other factors to affect UC progression and outcomes, evaluate the impact of TERT promoter mutations and TERT-mediated activation of human endogenous retrovirus genes on UC immunotherapy including Bacillus Calmette-Guérin therapy and immune checkpoint inhibitors. Finally, we suggest the standardization of a TERT assay and evaluation system for UC clinical practice.

Safety, Immunogenicity, and 1-Year Efficacy of Universal Cancer Peptide-Based Vaccine in Patients With Refractory Advanced Non-Small-Cell Lung Cancer: A Phase Ib/Phase IIa De-Escalation Study

PURPOSE

Universal cancer peptide-based vaccine (UCPVax) is a therapeutic vaccine composed of two highly selected helper peptides to induce CD4+ T helper-1 response directed against telomerase. This phase Ib/IIa trial was designed to test the safety, immunogenicity, and efficacy of a three-dose schedule in patients with metastatic non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

Patients with refractory NSCLC were assigned to receive three vaccination doses of UCPVax (0.25 mg, 0.5 mg, and 1 mg) using a Bayesian-based phase Ib followed by phase IIa de-escalating design. The primary end points were dose-limiting toxicity and immune response after three first doses of vaccine. Secondary end points were overall survival (OS) and progression-free survival at 1 year.

RESULTS

A total of 59 patients received UCPVax; 95% had three prior lines of systemic therapy. No dose-limiting toxicity was observed in 15 patients treated in phase Ib. The maximum tolerated dose was 1 mg. Fifty-one patients were eligible for phase IIa. The third and sixth dose of UCPVax induced specific CD4+ T helper 1 response in 56% and 87.2% of patients, respectively, with no difference between three dose levels. Twenty-one (39%) patients achieved disease control (stable disease, n = 20; complete response, n = 1). The 1-year OS was 34.1% (95% CI, 23.1 to 50.4), and the median OS was 9.7 months, with no significant difference between dose levels. The 1-year progression-free survival and the median OS were 17.2% (95% CI, 7.8 to 38.3) and 11.6 months (95% CI, 9.7 to 16.7) in immune responders (P = .015) and 4.5% (95% CI, 0.7 to 30.8) and 5.6 months (95% CI, 2.5 to 10) in nonresponders (P = .005), respectively.

CONCLUSION

UCPVax was highly immunogenic and safe and provide interesting 1-year OS rate in heavily pretreated advanced NSCLC.

The Role of Telomerase in Breast Cancer's Response to Therapy

Currently, breast cancer appears to be the most widespread cancer in the world and the most common cause of cancer deaths. This specific type of cancer affects women in both developed and developing countries. Prevention and early diagnosis are very important factors for good prognosis. A characteristic feature of cancer cells is the ability of unlimited cell division, which makes them immortal. Telomeres, which are shortened with each cell division in normal cells, are rebuilt in cancer cells by the enzyme telomerase, which is expressed in more than 85% of cancers (up to 100% of adenocarcinomas, including breast cancer). Telomerase may have different functions that are related to telomeres or unrelated. It has been shown that high activity of the enzyme in cancer cells is associated with poor cell sensitivity to therapies. Therefore, telomerase has become a potential target for cancer therapies. The low efficacy of therapies has resulted in the search for new combined and more effective therapeutic methods, including the involvement of telomerase inhibitors and telomerase-targeted immunotherapy.

Characterization of the T cell receptor repertoire and melanoma tumor microenvironment upon combined treatment with ipilimumab and hTERT vaccination

Background

This clinical trial evaluated a novel telomerase-targeting therapeutic cancer vaccine, UV1, in combination with ipilimumab, in patients with metastatic melanoma. Translational research was conducted on patient-derived blood and tissue samples with the goal of elucidating the effects of treatment on the T cell receptor repertoire and tumor microenvironment.

Methods

The trial was an open-label, single-center phase I/IIa study. Eligible patients had unresectable metastatic melanoma. Patients received up to 9 UV1 vaccinations and four ipilimumab infusions. Clinical responses were assessed according to RECIST 1.1. Patients were followed up for progression-free survival (PFS) and overall survival (OS). Whole-exome and RNA sequencing, and multiplex immunofluorescence were performed on the biopsies. T cell receptor (TCR) sequencing was performed on the peripheral blood and tumor tissues.

Results

Twelve patients were enrolled in the study. Vaccine-specific immune responses were detected in 91% of evaluable patients. Clinical responses were observed in four patients. The mPFS was 6.7 months, and the mOS was 66.3 months. There was no association between baseline tumor mutational burden, neoantigen load, IFN-γ gene signature, tumor-infiltrating lymphocytes, and response to therapy. Tumor telomerase expression was confirmed in all available biopsies. Vaccine-enriched TCR clones were detected in blood and biopsy, and an increase in the tumor IFN-γ gene signature was detected in clinically responding patients.

Conclusion

Clinical responses were observed irrespective of established predictive biomarkers for checkpoint inhibitor efficacy, indicating an added benefit of the vaccine-induced T cells. The clinical and immunological read-out warrants further investigation of UV1 in combination with checkpoint inhibitors.

Trial registration Clinicaltrials.gov identifier: NCT02275416. Registered October 27, 2014. https://clinicaltrials.gov/ct2/show/NCT02275416?term=uv1&draw=2&rank=6

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03624-z.