Survival analysis of multiple peptide vaccination for the selection of correlated peptides in urological cancers

TAS0313 plus Pembrolizumab for Post-Chemotherapy Immune Checkpoint Inhibitor-Naïve Locally Advanced or Metastatic Urothelial Carcinoma

We evaluated the efficacy and safety of TAS0313, a multi-epitope long peptide vaccine, plus pembrolizumab in post-chemotherapy immune checkpoint inhibitor-naïve patients with locally advanced/metastatic urothelial carcinoma (la/mUC). TAS0313 9 mg was administered subcutaneously followed by pembrolizumab 200 mg on Day 1, and as monotherapy on Day 8 and 15 of Cycles 1 and 2, and Day 1 of subsequent cycles in 21-day cycles. The primary endpoint was the objective response rate (ORR). Secondary endpoints included progression-free survival (PFS), overall survival (OS), and safety. Biomarkers of response were assessed. In 36 patients enrolled, the ORR was 33.3% (complete response: 7 patients; partial response: 5 patients). Median PFS was 5.0 months; 6- and 12-month progression-free rates were 46.4% and 36.5%, respectively. Median OS was not reached; 6-, 12-, and 24-month OS rates were 83.3%, 72.2%, and 55.1%, respectively. In post hoc analysis, patients with a tumor infiltrating CD8+ lymphocyte (CD8+ TIL) count ≥99 and/or programmed cell death ligand 1 (PD-L1) combined positive score (CPS) ≥50 and lymphocyte count >1,380 cells/μL had higher ORRs and prolonged PFS versus patients with a CD8+ TIL count <99, PD-L1 CPS <50, and lymphocyte count ≤1,380 cells/μL. Thirty-four (94.4%) patients receiving combination therapy experienced treatment-related adverse events (AE), with pyrexia (n = 15, 41.7%), injection-site reactions (n = 15, 41.7%), injection-site induration (n = 6, 16.7%), and malaise (n = 6, 16.7%) the most common. No grade ≥3 treatment-related AEs occurred in ≥10% of patients. TAS0313 plus pembrolizumab combination therapy showed promising efficacy and manageable safety in la/mUC. Clinical Trial Registration: JapicCTI-183824.

Immune responses of patients without cancer recurrence after a cancer vaccine over a long term

The present study aimed to clarify the humoral and cellular immune responses of patients with cancer who experienced no recurrence over a long term after receiving a cancer vaccine. The immune kinetics were investigated in response to a personalized peptide vaccination (PPV) among 44 Japanese patients without an active tumor at entry to the vaccination: Lung adenocarcinoma (n=11); colon (n=18); and breast cancer (n=15) (9, 10, 12, 8 and 5 patients with stage I, II, III and IV recurrences, respectively). The patients' immunoglobulin G (IgG) and cytotoxic T lymphocyte (CTL) activities were measured using a multiplexed Luminex assay and an interferon-γ release assay, respectively. There were no severe adverse events related to the PPV other than a grade III injection site reaction. A potent boost in IgG or CTL at the end of the 1st vaccination cycle was observed in 77% of the patients (n=84). The IgG levels were sustained throughout the follow-up period, whereas the CTL levels declined and were transient. A total of 37 of the 44 patients (84%) had no recurrence, with a median follow-up of 67.6 months (interquartile range, 45.6-82.8 months). Overall, the PPV induced long-term humoral immunity with transient cellular immunity in the majority of patients with cancer without an active tumor at their entry to the PPV.

The spliceosome factor sart3 regulates hematopoietic stem/progenitor cell development in zebrafish through the p53 pathway

Hematopoietic stem cells (HSCs) possess the potential for self-renew and the capacity, throughout life, to differentiate into all blood cell lineages. Yet, the mechanistic basis for HSC development remains largely unknown. In this study, we characterized a zebrafish smu471 mutant with hematopoietic stem/progenitor cell (HSPC) defects and found that sart3 was the causative gene. RNA expression profiling of the sart3^smu471 mutant revealed spliceosome and p53 signaling pathway to be the most significantly enriched pathways in the sart3^smu471 mutant. Knock down of p53 rescued HSPC development in the sart3^smu471 mutant. Interestingly, the p53 inhibitor, mdm4, had undergone an alternative splicing event in the mutant. Restoration of mdm4 partially rescued HSPC deficiency. Thus, our data suggest that HSPC proliferation and maintenance require sart3 to ensure the correct splicing and expression of mdm4, so that the p53 pathway is properly inhibited to prevent definitive hematopoiesis failure. This study expands our knowledge of the regulatory mechanisms that impact HSPC development and sheds light on the mechanistic basis and potential therapeutic use of sart3 in spliceosome-mdm4-p53 related disorders.

Cancer Vaccines for Genitourinary Tumors: Recent Progresses and Future Possibilities

BACKGROUND

In the last years, many new treatment options have widened the therapeutic scenario of genitourinary malignancies. Immunotherapy has shown efficacy, especially in the urothelial and renal cell carcinomas, with no particular relevance in prostate cancer. However, despite the use of immune checkpoint inhibitors, there is still high morbidity and mortality among these neoplasms. Cancer vaccines represent another way to activate the immune system. We sought to summarize the most recent advances in vaccine therapy for genitourinary malignancies with this review.

METHODS

We searched PubMed, Embase and Cochrane Database for clinical trials conducted in the last ten years, focusing on cancer vaccines in the prostate, urothelial and renal cancer.

RESULTS

Various therapeutic vaccines, including DNA-based, RNA-based, peptide-based, dendritic cells, viral vectors and modified tumor cells, have been demonstrated to induce specific immune responses in a variable percentage of patients. However, these responses rarely corresponded to significant survival improvements.

CONCLUSIONS

Further preclinical and clinical studies will improve the knowledge about cancer vaccines in genitourinary malignancies to optimize dosage, select targets with a driver role for tumor development and growth, and finally overcome resistance mechanisms. Combination strategies represent possibly more effective and long-lasting treatments.

Discrimination of a single nucleotide polymorphism in the haptoglobin promoter region, rs5472, using a competitive fluorophore-labeled probe hybridization assay following loop-mediated isothermal amplification

Personalized peptide vaccination, which involves activation of the host immune system against cancer cells using personalized peptide vaccines (PPVs), can improve overall survival in multiple cancer types. However, the clinical efficacies of PPVs vary for unknown reasons. Recently, a single nucleotide polymorphism (NG_012651.1:g.4461_5460[4960A>G]) in the haptoglobin promoter region, rs5472, was significantly associated with clinical response of PPV. Therefore, rs5472 is expected to be a predictive biomarker for PPV therapy. Here, we described a single nucleotide discrimination method for rs5472 analysis by combining the loop-mediated isothermal amplification and quenching probe methods. In evaluation of saliva samples, this method showed high concordance with the results of Sanger sequencing (100%, n = 36). Importantly, this method did not require calculation of melting temperature for single nucleotide discrimination and could therefore be carried out on a simple instrument. Accordingly, this method may be more robust and applicable to near-patient testing.

Identification of biomarkers for personalized peptide vaccination in 2,588 cancer patients

Peptide-based cancer vaccines have failed to provide sufficient clinical benefits in order to be approved in clinical trials since the 1990s. To understand the mechanisms underlying this failure, the present study investigated biomarkers associated with the lower overall survival (OS) among 2,588 patients receiving personalized peptide vaccination (PPV). Survival data were obtained from a database of 2,588 cancer patients including 399 patients with lung, 354 with prostate and 344 with colon cancer. They entered into phase II clinical trials of PPV in which 2 to 4 of 31 warehouse peptides were selected for vaccination on an individual patient basis based on human leukocyte antigen (HLA) class IA-types and pre-existing peptide-specific IgG levels. Higher pre-vaccination neutrophil, monocyte and platelet counts, and lower pre-vaccination lymphocyte and red blood cell counts were inversely associated with OS, with higher sensitivities in the proportions of neutrophils and lymphocytes, respectively. The most potent unfavorable and favorable factors for OS were the median percentage of neutrophils (>64.8%) or percentage of lymphocytes (>25.1%) with correlation coefficients (R²) of 0.98 and 0.92, respectively. Higher pre-vaccination levels of c-reactive protein and other inflammatory soluble factors were inversely associated with OS. Pre-vaccination peptide-specific immunity levels had no effect on OS, although lower immune boosting levels were inversely associated with OS. None of the 31 peptides was inversely associated with OS, although a few peptides were positively associated with it. On the whole, the findings of the present study suggested that pre-vaccination inflammatory signatures, but not those of post-vaccination immune induction, were associated with lower clinical benefits of PPV.

A phase I study of multi-HLA-binding peptides derived from heat shock protein 70/glypican-3 and a novel combination adjuvant of hLAG-3Ig and Poly-ICLC for patients with metastatic gastrointestinal cancers: YNP01 trial

Background

This phase I study aimed to evaluate the safety, peptide-specific immune responses, and anti-tumor effects of a novel vaccination therapy comprising multi-HLA-binding heat shock protein (HSP) 70/glypican-3 (GPC3) peptides and a novel adjuvant combination of hLAG-3Ig and Poly-ICLC against metastatic gastrointestinal cancers.

Methods

HSP70/GPC3 peptides with high binding affinities for three HLA types (A*24:02, A*02:01, and A*02:06) were identified with our peptide prediction system. The peptides were intradermally administered with combined adjuvants on a weekly basis. This study was a phase I dose escalation clinical trial, which was carried out in a three patients’ cohort; in total, 11 patients were enrolled for the recommended dose.

Results

Seventeen patients received this vaccination therapy without dose-limiting toxicity. All treatment-related adverse events were of grades 1 to 2. Peptide-specific CTL induction by HSP70 and GPC3 proteins was observed in 11 (64.7%) and 13 (76.5%) cases, respectively, regardless of the HLA type. Serum tumor marker levels were decreased in 10 cases (58.8%). Immunological analysis using PBMCs indicated that patients receiving dose level 3 presented with significantly reduced T cell immunoglobulin and mucin-domain containing-3 (TIM3)-expressing CD4 + T cells after one course of treatment. PD-1 or TIM3-expressing CD4 + T cells and T cell immunoreceptor with immunoglobulin and ITIM domains (TIGIT)-expressing CD8 + T cells in PBMCs before vaccination were negative predictive factors for survival.

Conclusions

This novel peptide vaccination therapy was safe for patients with metastatic gastrointestinal cancers.

Electronic supplementary material

The online version of this article (10.1007/s00262-020-02518-7) contains supplementary material, which is available to authorized users.

Development of tumour peptide vaccines: From universalization to personalization

In recent years, relying on the human immune system to kill tumour cells has become an effective means of cancer treatment. The development of peptide vaccines, which not only break the immune tolerance of a tumour but also attack malignant cells via specific antitumour immunity, has received increased attention in tumour immunization therapy due to their safety and easy preparation. The use of large-scale sequencing technology enables the continuous discovery of new tumour antigens. With improved accuracy of epitope prediction by computer simulation and the usage of a tetramer assay, cytotoxic lymphocyte epitopes can be screened and identified more easily. Transmembrane peptide and nanoparticle technologies promote more effective intake and delivery of antigens. Consequently, considerable evolution from universal to personalized peptide vaccines has taken place, and such vaccines induce an efficient and specific immune response targeting tumour neoantigens. Recently, genomic analysis and bioinformatics approaches have greatly facilitated the breakthrough of personalized peptide vaccines targeting neoantigens, resulting in a renewed interest in this field. Further, the combination of tumour peptide vaccines with checkpoint blockades may improve patient outcomes. In this review, we discuss the development of tumour peptide vaccines and the new technological progress, from universalization to personalization, to highlight the substantial promise of tumour peptide vaccines in clinical cancer immunotherapy.

Remarkable antitumor effect of nivolumab in a patient with metastatic renal cell carcinoma previously treated with a peptide-based vaccine

INTRODUCTION

The safety and efficacy of combination therapy comprising immune checkpoint inhibitors and cancer-specific peptide vaccines have not yet been established.

CASE PRESENTATION

A 71-year-old female metastatic renal cell carcinoma patient with multiple lung and pleural metastases. She had been treated with interferon alpha, sunitinib, axitinib, and pazopanib sequentially, but no clinical efficacy was observed. She participated in a clinical trial using cancer-specific peptide vaccine therapy. Initially no antitumor effect was observed, and vaccine therapy was ceased after two courses. But 3 months after the start of nivolumab, remarkable tumor shrinkage was observed at all metastatic sites, which resulted in almost complete response at 6 months. At 10 months, nivolumab was stopped due to cellulitis at the peptide vaccine inoculation site. Intriguingly, even after nivolumab discontinuation, complete response was maintained for more than 1 year.

CONCLUSION

We experienced a remarkable antitumor effect by nivolumab in a patient who was previously treated with vaccine therapy.

Substantial tumor regression in prostate cancer patient with extensive skeletal metastases upon Immunotherapy (APCEDEN): A case report

RATIONALE

Prostate cancer along with colorectal and lung cancers accounts for 42% of cancer cases in men globally. It is the first cancer indication for which the use of active immunotherapy, Sipuleucel-T (Provenge) was granted by the FDA in 2010. This study presents a case of prostate carcinoma and the tumour remission observed after administration of a personalised Dendritic cell vaccine (APCEDEN).

PATIENT CONCERNS

A 58 years old Caucasian male diagnosed with prostate carcinoma with GLEASON score 8. The patient had previously been diagnosed with Renal Cell Carcinoma (RCC) in 1996 and had undergone nephrectomy of the right kidney. PET CT scan revealed multiple intensely PSMA avid lesions noted in both lobes of the prostate gland with SUVmax -28.3 and the prostate gland measuring 3.2 × 3.2 cm displaying maximum dimensions.

DIAGNOSIS

FNAC followed by PETCT confirmed CA Prostate and further supported by increased serum PSA level.

INTERVENTIONS

The patient underwent personalised Dendritic Cell Immunotherapy APCEDEN regimen of six doses biweekly, in a time frame of 3 months were given both via intravenous and intradermal route. Six months post completion of APCEDEN, the patient was administered 6 booster shots for 6 months.

OUTCOMES

Progressive remission of carcinoma was observed along with reduction in PSA and Testosterone levels. PET CT showed decline in PSMA avidity by 50% with SUVmax -14.0 and normal size and shape of prostate gland.

LESSONS

Prostate carcinoma is the second most common cancer in men with majority of them exhibiting locally advanced disease. Apparently 20% to 30% of them are categorized as relapsed cases after various therapeutic interventions. Modulating immune system is an emerging therapy termed as Immunotherapy and potentiates the killing cancer cells via immune activation. Interestingly, prostate cancer is slow growing and it provides the scope and time to mount an anti-tumor response which makes it an attractive target for immunotherapy. This case study demonstrates the efficacy of APCEDEN Immunotherapy regimen resulting in a significant disease remission benefiting the patient.

Survival analysis of multiple peptide vaccination for the selection of correlated peptides in urological cancers

Peptide‐based cancer vaccines are able to induce strong immune responses, but their clinical results are unsatisfactory. To determine clinically correlated peptides, we analyzed survival data from urological cancer patients treated by personalized peptide vaccination (PPV), in which different multiple peptides were used for individual patients based on human leukocyte antigen (HLA) type and pre‐existing immunity. Survival data were obtained from a database of 265 urological cancer patients treated in 5 clinical PPV trials comprising 154 patients with castration‐resistant prostate cancer (CRPC) and 111 patients with advanced urothelial cancer (UC). Expression of tumor‐associated antigens (TAA) was evaluated in 10 prostate cancer tissues, 4 metastatic lymph nodes from prostate cancer, and 10 UC tissues using immunohistochemical staining. Clinical efficacy of individual peptides for overall survival was evaluated by the Cox proportional hazards regression model. All TAA coding candidate peptides used in PPV treatment were expressed in tumor cells from prostate cancer and UC samples except for p56Lck in both, and prostate‐specific antigen (PSA), prostatic acid phosphatase (PAP) and prostate‐specific membrane antigen (PSMA) in the UC samples. Patients with the following peptides had a significantly longer survival than patients without the peptides (hazard ratio <1.0, 95% confidence intervals <1.0 and P < .05): SART3‐109, PTHrP‐102, HNPRL‐140, SART3‐302 and Lck‐90 in CRPC patients, and EGF‐R‐800, Lck‐486, PSMA‐624, CypB‐129 and SART3‐734 in advanced UC patients, respectively. Correlated peptides selected using both survival data and pre‐existing immunity for PPV treatment may enhance the clinical benefits for urological cancer patients.