Hepatic arterial infusion chemotherapy for advanced hepatocellular carcinoma with portal vein tumor thrombosis: analysis of 48 cases

BACKGROUND

The prognosis of patients with hepatocellular carcinoma (HCC) with portal vein tumor thrombosis (PVTT) is extremely poor. The aim of this study was to elucidate the efficacy of hepatic arterial infusion chemotherapy (HAIC) for patients with advanced HCCs.

METHODS

Forty-eight HCC patients with PVTT were treated by HAIC via a subcutaneously implanted injection port. Of these, 14 had PVTT in the second portal branch and 34 patients had PVTT in the first portal branch or in the main portal trunk. One course of chemotherapy consisted of daily cisplatin (7 mg/m(2) for 1 hour on Days 1-5) followed by 5-fluorouracil (170 mg/m(2) for 5 hours on Days 1-5). Patients were scheduled to receive four serial courses of HAIC. Responders were defined as having either a complete response (CR) or partial response (PR) and nonresponders were defined as exhibiting stable disease or progressive disease. The prognosis after HAIC and factors related to survival were analyzed.

RESULTS

Following HAIC, 4 and 19 patients exhibited a CR and PR, respectively (response rate = 48%). The 1, 2, 3, and 5-year cumulative survival rates of 48 patients treated with HAIC were 45%, 31%, 25%, and 11%, respectively. Median survival periods for 23 responders and 25 nonresponders were 31.6 (range, 8.3-76.9) months and 5.4 (1.9-29.0) months, respectively. Therapeutic effect (P < 0.001) and hepatic reserve capacity (P = 0.021) were identified as significant prognostic factors by univariate analysis. Multivariate analysis identified only therapeutic effect as being significantly related to survival.

CONCLUSIONS

HAIC using low-dose cisplatin and 5-fluorouracil may be a useful therapeutic option for patients with advanced HCC with PVTT. HCC patients with PVTT who respond to HAIC could certainly have survival benefits.

Expression of the tumor-rejection antigen SART1 in brain tumors

We have reported a tumor-rejection antigen, SART1(259), possessing tumor epitopes capable of inducing cytotoxic T lymphocytes (CTLs) in epithelial-cancer patients. This study investigated the expression of SART1(259) antigen in brain tumors, to explore for a potential molecule for use in specific immunotherapy of patients with brain tumors. The SART1(259) antigen was detected in the cytosol fraction of 13 of 18 (72%) glioma cell lines and in 12 of 34 (35%) brain-tumor tissues, with a higher rate of expression among malignant gliomas (5/10, 50%) and schwannomas (3/4). HLA-A24-restricted and SART1-specific CTLs recognized the HLA-A24+ and SART1(259)+ glioma cells, and the levels of recognition correlated both with HLA-A24-antigen expression level and with the concentration of the SART1 peptide antigen. Therefore, the SART1(259) antigen could be a target molecule for specific immunotherapy of patients with brain tumors expressing HLA-class-1 antigens.

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.

A phase II study of a personalized peptide vaccination for chemotherapy-resistant advanced pancreatic cancer patients

Pancreatic cancer is one of the most aggressive cancers with a median survival time (MST) of <6 months in chemotherapy-resistant patients. Therefore, the development of novel treatment modalities is needed. In the present study, a phase II study of personalized peptide vaccination (PPV) was conducted, in which vaccine antigens were selected and administered based on the pre-existing IgG responses to 31 different pooled peptides, for 41 chemotherapy-resistant advanced pancreatic cancer patients. No vaccine-related severe adverse events were observed. IgG responses specific to at least one of the vaccine peptides were augmented in 14 of 36 patients (39%) and in 18 of 19 patients (95%) tested after the 5th and 11th vaccination, respectively. MST from the first vaccination was 7.9 months with a 1-year survival rate of 26.8%. Higher serum amyloid A (SAA) and C-reactive protein (CRP) levels in pre-vaccination plasma were unfavorable factors for overall survival (OS). Due to the safety profile and the potential clinical efficacy, the conduction of additional clinical trials of PPV for chemotherapy-resistant advanced pancreatic cancer patients is warranted.

Personalized peptide vaccination for advanced biliary tract cancer: IL-6, nutritional status and pre-existing antigen-specific immunity as possible biomarkers for patient prognosis

Considering that the prognosis of patients with advanced biliary tract cancer (BTC) remains very poor, with a median survival of less than 1 year, new therapeutic approaches need to be developed. In the present study, a phase II clinical trial of personalized peptide vaccination (PPV) was conducted in advanced BTC patients to evaluate the feasibility of this treatment and to identify potential biomarkers. A maximum of 4 human leukocyte antigen-matched peptides, which were selected based on the pre-existing host immunity prior to vaccination, were subcutaneously administered (weekly for 6 consecutive weeks and bi-weekly thereafter) to 25 advanced BTC patients without severe adverse events. Humoral and/or T cell responses specific to the vaccine antigens were substantially induced in a subset of the vaccinated patients. As shown by multivariate Cox regression analysis, lower interleukin-6 (IL-6) and higher albumin levels prior to vaccination and greater numbers of selected vaccine peptides were significantly favorable factors for overall survival [hazard ratio (HR)=1.123, 95% confidence interval (CI) 1.008-1.252, P=0.035; HR=0.158, 95% CI 0.029-0.860, P=0.033; HR=0.258, 95% CI 0.098-0.682, P=0.006; respectively]. Based on the safety profile and substantial immune responses to vaccine antigens, PPV could be a promising approach for refractory BTC, although its clinical efficacy remains to be investigated in larger-scale prospective studies. The identified biomarkers are potentially useful for selecting BTC patients who would benefit from PPV.

Detection of skewed X-inactivation in two female carriers of vasopressin type 2 receptor gene mutation

Most cases of congenital nephrogenic diabetes insipidus (NDI) are inherited in an X-linked manner, which is due to the mutations of the vasopressin type 2 receptor (V2R) gene. However, recent reports have presented female NDI patients with heterozygote V2R gene mutations. The mechanism of inheritance was thought to be skewed X-inactivation. We present a family with congenital NDI. Three male members were diagnosed with NDI, and examination of their V2R gene revealed a G inserted at nucleotide 804 of the open reading frame. Three female individuals display different degrees of symptoms of NDI, and all of them possess both the normal and abnormal genes. The X-inactivation patterns of the female members were investigated via the detection of methylated trinucleotide repeat in the human androgen receptor gene. The grandmother showed extremely skewed methylation of one X chromosome, and the mother revealed moderately skewed methylation. The daughter of the grandmother's sister, who has no symptoms of NDI, showed random methylation. The highly skewed X-inactivation pattern of the grandmother suggests that her NDI phenotype is caused by dominant methylation of the normal allele of V2R gene.

Phase I clinical study of a personalized peptide vaccination for patients infected with hepatitis C virus (HCV) 1b who failed to respond to interferon-based therapy

To assess the safety and immune responses to a personalized peptide vaccination of hepatitis C virus (HCV) 1b-derived peptides, 12 HCV1b-positive patients, who were unresponsive to interferon-based therapy, were enrolled in this study. The reactivity of the pre-vaccination peripheral blood T cells and plasma IgG to four vaccine candidate peptides capable of inducing cytotoxic T lymphocytes (CTLs) in HLA-A24(+) patients was examined and only the reactive peptides were then administered bi-weekly at three different dose settings. The study was well tolerated with no severe toxicity. Augmentation of peptide-specific CTL activity and IgG in response to at least one of the vaccinated peptides was observed after the 7th vaccination. Decrease of serum alanine aminotransferase and HCV-RNA levels after the 14th vaccination was also observed in five and three patients, respectively.

A randomized phase II trial of personalized peptide vaccine with low dose cyclophosphamide in biliary tract cancer

Since the prognosis of advanced biliary tract cancer (aBTC) still remains very poor, new therapeutic approaches, including immunotherapies, need to be developed. In the current study, we conducted an open‐label randomized phase II study to test whether low dose cyclophosphamide (CPA) could improve antigen‐specific immune responses and clinical efficacy of personalized peptide vaccination (PPV) in 49 previously treated aBTC patients. Patients with aBTC refractory to at least one regimen of chemotherapies were randomly assigned to receive PPV with low dose CPA (100 mg/day for 7 days before vaccination) (PPV/CPA, n = 24) or PPV alone (n = 25). A maximum of four HLA‐matched peptides were selected based on the pre‐existing peptide‐specific IgG responses, followed by subcutaneous administration. T cell responses to the vaccinated peptides in the PPV/CPA arm tended to be greater than those in the PPV alone arm. The PPV/CPA arm showed significantly better progression‐free survival (median time: 6.1 vs 2.9 months; hazard ratio (HR): 0.427; P = 0.008) and overall survival (median time: 12.1 vs 5.9 months; HR: 0.376; P = 0.004), compared to the PPV alone arm. The PPV alone arm, but not the PPV/CPA arm, showed significant increase in plasma IL‐6 after vaccinations, which might be associated with inhibition of antigen‐specific T cell responses. These results suggested that combined treatment with low dose CPA could provide clinical benefits in aBTC patients under PPV, possibly through prevention of IL‐6‐mediated immune suppression. Further clinical studies would be recommended to clarify the clinical efficacy of PPV/CPA in aBTC patients.

Phase I clinical study of a peptide vaccination for hepatitis C virus-infected patients with different human leukocyte antigen-class I-A alleles

Hepatitis C virus (HCV) infection has a high risk of liver cirrhosis and hepatocellular carcinoma at later stages. We recently identified a peptide derived from the HCV core protein capable of inducing both cellular and humoral responses to nearly all HCV-positive patients in Japan with different human leukocyte antigen (HLA)-class I-A alleles. To assess the safety and immune responses to this novel peptide, we conducted a phase I dose-escalation study of the vaccination for 26 HCV-positive patients who were either non-responders to the interferon-based therapy (n = 23) or refused it (n = 3). The regimen was well tolerated, with no severe vaccine-related toxicity. Twenty-five and 22 patients completed the first and second cycle vaccination (6 and 12 vaccine injections), respectively. After a series of six vaccine injections, peptide-specific CTL activity was augmented in peripheral blood mononuclear cells from 15 of 25 patient samples, with an expected optimal dose of 1 mg peptide. After 12 vaccine injections, peptide-specific IgG production was augmented in plasma from the majority of patients (15 of 22 patients) tested, but not in a dose-dependent fashion. There were two HCV RNA responders with >1 log declines. Among patients whose pre-vaccination levels of alanine aminotransferase and alpha feto-protein exceeded the normal ranges, a <30% decrease was found in 7 of 24 and three of six patients, respectively. Because of its tolerability and higher rate of immune boosting, this protocol is recommended for a phase II study to investigate its clinical efficacy.

A decrease in AFP level related to administration of interferon in patients with chronic hepatitis C and a high level of AFP

It is known that there is a very high incidence of hepatocellular carcinoma (HCC) among patients with type C chronic hepatitis and cirrhosis, and alpha -fetoprotein (AFP) has been widely used as a diagnostic marker for HCC. However, there are some patients showing continuous high AFP values but no evidence of HCC, and some studies have defined such patients as a high-risk group for HCC. In vitro study has shown that interferon (IFN) inhibits cell proliferation and enhances apoptosis as well as specific cytotoxic T lymphocytes against HCC, resulting in direct anticancer actions. In this study, we investigated the effect of IFN on AFP changes in chronic hepatitis C patients. Of 40 patients with chronic hepatitis C in whom diagnostic imaging confirmed the absence of HCC, 24 patients showed high pretreatment AFP values (high AFP group: AFP level > 10 ng/dl; mean +/- SD, 46.3 +/- 41.5 ng/dl) and 16 showed low pretreatment AFP values (low AFP group: pretreatment AFP level < or = 10 ng/dl; mean +/- SD, 5.3 +/- 2.2 ng/dl). Pretreatment clinical parameters were statistically evaluated in relation to the AFP value. In the high AFP group, the platelet count, albumin level, and prothrombin (%) were significantly lower (P = 0.047, P = 0.0002, and P = 0.044, respectively), suggesting that AFP value increases with advancing liver disease. Subsequently 27 patients were administered IFN (IFN group), and the remaining 13 patients were administered Stronger Neo-minophagen C (SNMC), a glycyrrhizin preparation (SNMC group), as a control group receiving liver-protective therapy. Alanine aminotransferase was reduced in both the IFN and the SNMC group (mean, 132.56 to 60.07 mg/ml [P < 0001] and 147.85 to 56.23 mg/ml [P = 0.0240], respectively). AFP was significantly reduced in the IFN group (mean, 30.03 to 12.65 ng/ml; P = 0.0034), but there was no significant change in AFP in the SNMC group (mean, 29.70 to 39.17 ng/ml). AFP is useful for diagnosing HCC; however, some patients show a persistently high AFP level in the absence of HCC, and these patients have been described as a high-risk group for HCC. In this study, we found that IFN therapy but not SNMC universally reduced the AFP baseline. Since AFP is a significant predictor for HCC, therapeutic strategies for hepatitis C, e.g., long-term low-dose IFN treatment, may reduce hepatocarcinogenesis.

Radiofrequency ablation combined with transarterial chemoembolization for intermediate hepatocellular carcinoma

AIM

Radiofrequency ablation therapy (RFA) combined with transarterial chemoembolization (TACE) (combination therapy) is effective for early-stage hepatocellular carcinoma (HCC). The aim of this study was to compare the long-term effects of combination therapy with supportive care alone for intermediate HCC.

METHODS

The study included 58 patients with intermediate HCC who received combination therapy (n = 34) or supportive care alone (n = 24). The inclusion criteria were a single nodule of more than 50 mm in diameter or two to three nodules, each measuring more than 30 mm in diameter, or more than three nodules, no vascular invasion and no extrahepatic metastasis.

RESULTS

The overall survival rates at 1, 2, 3 and 5 years of the combination therapy group (91%, 65%, 53% and 27%, respectively) were significantly better (P < 0.0001) than those of the supportive care group (42%, 8%, 8% and 0%, respectively). Multivariate analysis identified treatment modality (combination therapy vs supportive care alone: P < 0.0001, risk ratio [RR] = 4.290 [95% confidence interval [CI] = 2.157-8.529]) and serum α-fetoprotein (P = 0.017, RR = 2.318 [95% CI = 1.166-4.610]) as independent and significant factors of overall survival.

CONCLUSION

The combination of TACE and RFA is a safe and effective therapy in patients with intermediate HCC.

A simultaneous monitoring of Lens culinaris agglutinin A-reactive alpha-fetoprotein and des-gamma-carboxy prothrombin as an early diagnosis of hepatocellular carcinoma in the follow-up of cirrhotic patients

To elucidate the risk factors for developing hepatocellular carcinoma (HCC) during the follow-up of patients with liver cirrhosis (LC), outpatients with LC were examined periodically by means of serum biochemical assessments, ultrasonography, and computed tomography. Risk factors for HCC were statistically analyzed. We also examined an efficacy of Lens culinaris agglutinin A-reactive profiles of alpha-fetoprotein (AFP-L3%) and des-gamma-carboxy prothrombin (DCP) value using a highly sensitive DCP determination kit (ED036) for the early recognition of HCC. The AFP-L3% and the ED036 value were retrospectively determined with stored serum samples. HCC was diagnosed in 21 of the 78 patients with LC during the follow-up period (mean follow-up period: 42 months). The estimated cumulative incidence of HCC was 25% with 3 years and 48% with 5 years. The most significant risk factor for the development of HCC in LC patients was found to be the mean serum AFP concentration from the year before the HCC detection (p=0.02). At the time of the recognition of HCC, the positive rates of the tumor markers were: serum AFP concentration 14%, serum DCP value 5%, AFP-L3% was 33%, and that of ED036 43%. The positive rate in collaborative use of AFP-L3% and ED036 was 67%. The simultaneous determination of the AFP-L3% and the ED036 value was shown to be effective for the early detection of HCC.

[Studies on Rehmanniae radix. III. The relation between changes of constituents and improvable effects on hemorheology with the processing of roots of Rehmannia glutinosa]

The relation between constituents and effects on hemorheology with processing of root of Rehmannia glutinosa was investigated. With the processing to dried or steamed root from crude root, the content of stachyose, which was the highest component in crude root, was decreased and the content of manninotriose was increased. Iridoid glycoside, catalpol, was gradually decreased with the processing. From these results, the content of carbohydrates and catalpol made it possible to estimate the quality of Rehmanniae Radix by processings. On the other hand, the change of pharmacological activities with the processing was investigated. The 50% ethanolic extract (BJ-ext) from steamed root of R. glutinosa increased erythrocyte deformability and erythrocyte ATP contents, inhibited polybrene-induced erythrocyte aggregation, and promoted an activity of fibrinolytic system. The extracts from crude or dried root had weak or no effect. The crude or dried root and steamed root of R. glutinosa showed the different pharmacological activities, and the quality of Rehamanniae Radix by processings may be estimated by investigation of correlation between the changes of constituents and improvable effects of hemorheology.

CD4+ hepatic cancer-specific cytotoxic T lymphocytes in patients with hepatocellular carcinoma

We investigated T cell immunity against hepatocellular carcinoma (HCC), and showed that both peripheral blood mononuclear cells and tumor-infiltrating lymphocytes incubated with interleukin-2 alone displayed HLA-nonrestricted but hepatic cancer-specific cytotoxicity in a majority of patients with HCC. Namely, they lysed both HCC and cholangiocellular carcinomas in an HLA-nonrestricted manner, but they did not lyse any tumors with the other histological types tested, normal hepatocytes, or the cells transfected with hepatitis C virus or MUC1 gene. These CTL lines and clones were phenotypically CD3+CD4+CD8-. These unique CTL could play important roles in T cell immunity against HCC.

Personalized peptide vaccination as second-line treatment for metastatic upper tract urothelial carcinoma

This study investigated the applicability of personalized peptide vaccination (PPV) for patients with metastatic upper tract urothelial cancer (mUTUC) after failure of platinum-based chemotherapy. In this single arm, open-label, phase II clinical trial, patients with mUTUC received PPV at a single institution. Personalized peptide vaccination treatment used a maximum of four peptides chosen from 27 candidate peptides according to human leukocyte antigen types and peptide-reactive IgG titers, for six s.c. injections weekly as one cycle. The safety of PPV, as well as its influence on host immunity and effect on overall survival were assessed. Forty-eight patients were enrolled in this study. Personalized peptide vaccinations were well tolerated without severe adverse events. Median survival time was 7.3 months (95% confidence interval [CI], 5.3-13.1) with 13.0 months for patients receiving combined salvage chemotherapy (95% CI, 5.7-17.5) and 4.5 months for patients receiving PPV alone (95% CI, 1.7-10.1) (P = 0.080). Patients with positive CTL responses showed a significantly longer survival than patients with negative CTL responses (hazard ratio, 0.37; 95% CI, 0.16-0.85; P = 0.019). Multivariate Cox regression analysis showed that lower numbers of Bellmunt risk factors and lower levels of B-cell activating factor were significantly associated with favorable overall survival for patients under PPV treatment. This study indicated that PPV for patients with mUTUC after failure of platinum-based chemotherapy induced substantial peptide-specific CTL responses without severe adverse events and has the potential to prolong survival when combined with salvage chemotherapy. UMIN Clinical Trials Registry ID: 000001854.

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.

Humoral immune responses to CTL epitope peptides from tumor-associated antigens are widely detectable in humans: a new biomarker for overall survival of patients with malignant diseases

Both cellular and humoral immune responses are crucial to induce potent anti-tumor immunity, but most of currently conducted peptide-based cancer vaccines paid attention to cellular responses alone, and none of them are yet approved as a therapeutic modality against cancer patients. We investigated humoral immune responses to CTL epitope peptides derived from tumor-associated antigens in healthy donors and patients with various diseases to facilitate better understanding of their distribution patterns and potential roles. Bead-based multiplex assay, ELISA, and Western blotting were used to measure immunoglobulins reactive to each of 31 different CTL epitope peptides. Importantly, the sums of anti-peptide IgG levels specific to 31 CTL epitope peptides were well correlated with better overall survival (OS) in patients with malignant diseases. Our results suggested that humoral immune responses to CTL epitope peptides were widely detectable in humans. Measurement of immunoglobulins specific to CTL epitope peptides may provide a new biomarker for OS of patients with malignant diseases, although it still remains to be determined whether the correlations between humoral immune responses to epitope peptides and OS are observed only for the CTL epitopes used, or also for other panels of peptides. Quantity of circulating IgG reactive to these peptides was also discussed.

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.

Antibody Reactive to a Hepatitis C Virus (HCV)-Derived Peptide Capable of Inducing HLA-A2 Restricted Cytotoxic T Lymphocytes Is Detectable in a Majority of HCV-Infected Individuals without HLA-A2 Restriction

Hepatitis C virus (HCV) is a single-strand RNA virus. Approximately 170 million people around the world are persistently infected and are at risk of liver cirrhosis or cancer. There is an urgent need to develop both therapeutic and diagnostic modalities of HCV. One approach to achieve these goals would be to determine highly immunodominant HCV peptides which are recognized by both cellular and humoral immunities. This study reports one such peptide, HCV-core protein at positions 35-44, having HLA-A2 binding motifs. IgG specific to this CTL-epitope peptide is consistently detectable in a majority of the patients with HCV infection regardless of the different HLA types, different disease conditions, and different HCV-genotypes tested. The sequence LPRR at positions 37-40 is considered to be the fine epitope recognized by the IgG. These results may provide new insights for the development of both therapeutic and diagnostic modalities of HCV at lower costs.

A new epitope peptide derived from hepatitis C virus 1b possessing the capacity to induce cytotoxic T-lymphocytes in HCV1b-infected patients with HLA-A11, -A31, and -A33

BACKGROUND

Hepatitis C virus (HCV) frequently causes chronic hepatitis, cirrhosis, and hepatocellular carcinoma after long-term persistent infection. Among various genotypes of HCV, HCV1b is resistant to standard interferon therapy, and thus the development of new treatment modality is needed.

RESULTS

To provide a scientific basis for specific immunotherapy for HCV1b, we investigated HCV1b-derived epitope peptides recognized by human leukocyte antigen (HLA)-A11, -A31, or -A33-restricted cytotoxic T-lymphocytes (CTLs), and report here three novel vaccine candidate peptides selected by both antibody screening and CTL-inducing capacity from among 46 peptides of conserved regions of HCV1b sequences with binding motifs to HLA-A11, -A31, and -A33. Significant levels of IgG reactive to each of the three peptides were detected in the plasma of more than 50% of the HCV1b(+) patients. One peptide at positions 30-39 of the core protein induced peptide-specific CTLs from peripheral blood mononuclear cells (PBMCs) of HLA-A11(+), -A31(+), and -A33(+) patients. The other two peptides at positions 35-43 of the core protein and at positions 918-926 of the non-structural protein 2 also induced peptide-specific CTLs from the PBMCs of HLA-A11(+) and -A33(+) patients.

CONCLUSION

Therefore, the peptide at positions 30-39 of the core protein could be an appropriate target molecule of specific immunotherapy for all HLA-A11(+), -A31(+), and -A33(+) patients with HCV1b-related diseases.

Long-term outcome of elderly patients (75 years or older) with hepatocellular carcinoma

AIM

The aim of this study was to evaluate the long-term outcome of elderly patients with hepatocellular carcinoma (HCC) aged 75 years or older.

METHODS

The study included 422 patients with HCC, who were divided into two age groups: 75 years or older (n = 140) and younger than 75 (n = 282). Outcomes were compared between the two groups.

RESULTS

The number of elderly patients treated with supportive care alone (33 patients; 24%) was significantly higher than younger patients (30 patients; 11%, P < 0.01). The 1-, 3-, 5- and 7-year overall survival rates of the elderly patients (81%, 55%, 39% and 23%, respectively) were worse than those of younger patients (85%, 64%, 49% and 36%, respectively, P = 0.042). However, the overall survival rate of the elderly group after excluding 63 patients treated with supportive care alone, was similar to that of the younger group (P = 0.615). Multivariate analysis identified age, total bilirubin levels, albumin levels, serum des-γ-carboxy prothrombin levels, tumor size, number of HCC nodules, vascular invasion, extrahepatic metastasis and treatment modality as independent and significant factors of overall survival.

CONCLUSION

Advanced age is a negative prognostic factor in patients with HCC due to the tendency for frequent use of conservative treatment rather than locoregional or surgical treatment.

A peptide derived from hepatitis C virus (HCV) core protein inducing cellular responses in patients with HCV with various HLA class IA alleles

C35-44 peptide is a well known HLA-A2-restricted CTL epitope originating from hepatitis C virus (HCV) core protein. It was reported that the majority of HCV positive patients had significant levels of serum IgG specific to this peptide. This study addressed whether C35-44 peptide could induce CTL activity restricted to various HLA class IA alleles or could not. This peptide demonstrated binding activity to HLA-A*2402, -A*2601, -A*3101, and -A*3303 molecules, but not to HLA-A*1101 by means of stabilization assay. This peptide also induced CTL activity restricted to each of them, except HLA-A11(+) peripheral blood mononuclear cells from HCV 1b(+) patients by means of (51)Cr-release assay. With regard to HLA-A2 subtypes, this peptide demonstrated binding activity to HLA-A*0201 and -A*0206, but not to -A*0207 molecules. Furthermore, this peptide induced CTL activity from both the patients and healthy donors with all the HLA class IA molecules mentioned above by means of interferon-gamma production assay. These results may provide new insights for the development of a novel peptide vaccine against HCV compatible with various HLA class IA types.

Expression of the SART1 tumor rejection antigen in renal cell carcinoma

We have previously described the SART1 gene, which encodes both the SART1(259) antigen expressed in the cytosol of the majority of squamous cell carcinomas and some adenocarcinomas and the SART1(800) antigen expressed in the nucleus of the majority of proliferating cells. The SART1(259) antigen is recognized by HLA-A24 and A26-restricted cytotoxic T lymphocytes (CTLs). The present study investigated the expression of these two antigens in renal cell carcinomas (RCCs) in order to identify an appropriate molecule for use in specific immunotherapy for RCC patients. These two antigens were detected in all RCC cell lines and cells of the primary cultures of the RCCs tested. Further, they were detectable in cells of the primary cultures of non-tumorous kidney tissues. In contrast to these cultured cells, SART1(259) was detectable in only a few uncultured RCC tissues (5/20, 25%) and was undetectable in non-tumorous kidney tissues. SART1(800) was also scarcely detectable in uncultured RCC tissues (3/20, 15%) and non-tumorous kidney tissues (4/20, 20%). HLA-A2402-restricted and tumor-specific CTL (KE4-CTL) used for the cloning of the SART1 gene showed significant levels of cytotoxicity to both the cells from the RCC cell line and the cells from the primary cultures of RCC tissues, but did not lyse any normal cells, including cells from the primary cultures of non-tumorous kidney tissues. The SART1-derived peptide at positions 690-698 induced HLA-A24 restricted CTLs cytotoxic to RCC cells from peripheral blood mononuclear cells (PBMCs) of RCC patients. Therefore, the SART1 peptide could be an appropriate molecule for use in peptide-based specific immunotherapy for RCC patients.

Feasibility study of personalized peptide vaccination for hepatocellular carcinoma patients refractory to locoregional therapies

Overall survival of patients with hepatocellular carcinoma (HCC) refractory to locoregional therapy is dismal, even following treatment with sorafenib, a multikinase inhibitor. To develop a more efficacious treatment, we undertook a feasibility study of personalized peptide vaccination (PPV) for HCC, in which the peptides were selected from 31 peptide candidates based on the pre‐existing immunity. Twenty‐six HCC patients refractory to locoregional therapies (cohort 1) and 30 patients refractory to both locoregional and systemic therapies (cohort 2) were entered into the study. There were no severe adverse events related to PPV except for one injection site reaction. At the end of the first cycle of six vaccinations, successful CTL or IgG boosting was observed in 57% or 46% of patients in cohort 1 and in 54% or 52% of patients in cohort 2, respectively. Successful IgG boosting at the end of the second cycle was observed in the majority of patients tested. Median overall survival was 18.7 months (95% confidence interval, 12.2–22.5 months) in cohort 1, and 8.5 months (95% confidence interval, 5.9–12.2 months) in cohort 2. Based on the higher rates of immune boosting and the safety profile of PPV, further clinical studies of PPV would be warranted for patients with HCC refractory to not only locoregional therapy but also both locoregional and systemic therapies. The protocol of this study was registered with the UMIN Clinical Trials Registry (UMIN000001882 and UMIN000003590).