The Immunogenicity and Safety Profile for KM-248, a Combined Measles, Mumps, and Rubella Vaccine, and Its Noninferiority to the Measles Vaccine in Healthy Japanese Children: a Phase 3 Randomized Multicenter Single-Blind Clinical Trial.

The domestic combined measles-mumps-rubella (MMR) vaccine was withdrawn in Japan in 1993 following an outbreak of aseptic meningitis attributed to the mumps component of the cocktail. KM-248 is an MMR vaccine (M-M-R®II), manufactured by Merck & Co., Inc. (Kenilworth, NJ, USA) and registered and approved in 74 countries, but which has not been approved in Japan. This multicenter, randomized, single-blind study, was designed to evaluate the noninferiority of the KM-248 measles component in terms of immunogenicity when compared to the control measles vaccine already approved in Japan and the seroconversion rates for these three viruses following KM-248 administration. Vaccination with KM-248 in children aged 12-90 months (n = 178) induced robust immune responses to measles, mumps, and rubella viruses. The seroconversion rate for the measles virus by the measles component of KM-248 (n = 172) was shown to be non-inferior to that of the control measles vaccine (n = 85). No serious adverse reactions, such as aseptic meningitis or anaphylaxis, were observed. Fever is one of the most common adverse reactions associated with vaccination and was observed in approximately half of the participants. KM-248 administered to healthy Japanese children aged between 12 and 90 months demonstrated a comparable safety and efficacy profile to the control vaccine.

Clinical phase II and III studies of an AS03-adjuvanted H5N1 influenza vaccine produced in an EB66® cell culture platform.

BACKGROUND: We have developed an AS03-adjuvanted H5N1 influenza vaccine produced in an EB66® cell culture platform (KD-295). OBJECTIVES: In accordance with Japanese guidelines for development of pandemic prototype vaccines, the phase II study was conducted in a double-blind, randomized, parallel-group comparison study and the phase III study was conducted in an open-label, non-randomized, uncontrolled study. METHODS: Healthy adult volunteers aged 20 - 64 years enrolled in the phase II and III studies (N = 248 and N = 369) received KD-295 intramuscularly twice with a 21-day interval. After administration, immune response and adverse events were evaluated. In the phase II study, four different vaccine formulations were compared: MA (3.75 µg hemagglutinin [HA] antigen + AS03 adjuvant system), MB (3.75 µg HA + 1/2AS03), HA (7.5 µg HA + AS03), and HB (7.5 µg HA + 1/2AS03). In the phase III study, the MA formulation was further evaluated. RESULTS: In the phase II study, all four vaccine formulations were well-tolerated and no SAE related to vaccination were observed. The MA formulation was slightly more immunogenic and less reactogenic among the vaccine formulations. Therefore, the MA formulation was selected for the phase III study, and it was well-tolerated and no serious adverse drug reactions were observed. The vaccine fulfilled the three immunogenicity criteria described in the Japanese guidelines. CONCLUSIONS: These data indicate that the MA formulation of KD-295 was well-tolerated and highly immunogenic and it can be considered a useful pandemic and pre-pandemic influenza vaccine.

Emerging RAS, BRAF, and EGFR mutations in cell-free DNA of metastatic colorectal patients are associated with both primary and secondary resistance to first-line anti-EGFR therapy.

Oncogenic RAS mutations are negative biomarkers of response to epidermal growth factor receptor (EGFR) blockade. RAS mutations are usually detected in biopsies of primary colorectal tumors. However, the genomic profiles of primary tumors and metastases are not always concordant, and chemotherapeutic agents can alter the tumor molecular landscape. Cell-free DNA (cfDNA) is a novel tool to detect molecular heterogeneity. This study evaluated the clinical utility of cfDNA to predict primary or secondary resistance to EGFR blockade in patients with metastatic colorectal cancer. Thirty metastatic colorectal cancer patients without RAS and BRAF mutations were prospectively enrolled and treated with cytotoxic agents and EGFR blockade as first-line therapy. cfDNA was analyzed for the presence of RAS, BRAF, and EGFR (S492R) point mutations before initiating chemotherapy and every 2 months during chemotherapy. The analysis was performed in 223 plasma samples from all 30 patients. Of the 30 patients, five had RAS mutations in their cfDNA before starting chemotherapy and did not respond. Twenty-four of the remaining 25 patients without cfDNA RAS mutations had a response. Twenty of the 24 responders developed secondary resistance and cfDNA RAS mutations were found in 17 of the 20. cfDNA BRAF mutations were found in seven, and EGFR mutations were found in eight of the 20 patients. Emerging RAS, BRAF, and EGFR mutations occurred in patients with primary and secondary resistance to EGFR blockade. The detection of these mutations in cfDNA is a promising approach to predict treatment response and secondary resistance.

Circulating cell-free long DNA fragments predict post-hepatectomy recurrence of colorectal liver metastases.

INTRODUCTION: Most patients with colorectal liver metastases, who undergo hepatectomy, experience recurrence. Although the prognosis is poorer for patients with early recurrence (within 6 months after hepatectomy) compared with later recurrence, no biomarker has been identified to predict early recurrence. Minimal residual disease (MRD) in patients who undergo curative surgery is the main cause of recurrence. In cancer patients, long fragment cell-free DNA is detected, and the presence of long fragments of cell-free DNA after surgery can indicate MRD. In this study, we developed a novel biomarker to predict early recurrence of colorectal liver metastases using cell-free DNA. MATERIALS AND METHODS: Forty-one patients with colorectal liver metastases were enrolled. Peripheral blood samples were collected before and at 1 month after hepatectomy. Cell-free DNA was extracted from 1 ml plasma, and the long fragment/ß-globin ratio, which can indicate MRD, was measured by real-time polymerase chain reaction. RESULTS: Three of 21 patients (14.3%) with decreases in the long cell-free DNA fragment/ß-globin ratio after hepatectomy developed early recurrence compared with twelve of 20 patients (60.0%) with an increased ratio (P = 0.002). Patients with a decreased long fragment/ß-globin ratio after hepatectomy had significantly longer recurrence-free survival compared with patients with an increased ratio (366 vs 102 days, P < 0.001). CONCLUSION: The cell-free DNA long fragment/ß-globin ratio may serve as an effective biomarker of early recurrence in patients with colorectal liver metastases, who undergo hepatectomy.

Liquid Biopsy for the Management of Patients with Colorectal Cancer.

BACKGROUND: Liquid biopsy is a collective term that refers to the analysis of tumor-derived biomarkers isolated from biological fluids of cancer patients. Recently, many authors reported the usefulness of liquid biopsy for the management of malignancy. Summary and Key Messages: The peripheral blood of cancer patients is a pool of cells and/or cell products derived from the primary or metastatic tumor, including circulating tumor cells (CTCs), circulating free (cf) DNA or RNA, and exosomes containing proteins, nucleic acids, and lipids. CTCs are tumor cells that can be isolated from peripheral blood. Free circulating DNA with a tumor-specific mutation is called circulating tumor DNA (ctDNA). Some patients who undergo curative surgery experience recurrent disease, which can be due to the presence of minimal residual disease (MRD). Thus, MRD indicates a high risk of relapse. Detection of ctDNA or CTC after surgery is a direct proof of MRD. Molecular volume (e.g., the number of CTCs and level of ctDNA) might reflect tumor burden, thus high molecular volume may indicate poor prognosis. The most notable application of liquid biopsy in cancer is to understand spatial and temporal heterogeneities. Heterogeneity is one of the causes of refractoriness and hampers prediction of chemotherapeutic effect. Emerging mutations that are not present in primary tumors but are found in their metastases can be detected in ctDNA. Some colorectal cancer patients with wild-type RAS do not respond to epidermal growth factor receptor blockade. In a subset of these patients, RAS mutation is detected in ctDNA, indicating heterogeneity.

Epidemiology of rubella and congenital rubella syndrome in Japan before 1989.

Epidemiological studies of rubella and congenital rubella syndrome (CRS) in Japan have been conducted since the first nationwide rubella epidemic of 1965-1969 and subsequent epidemics of 1975-1977, 1982, 1987-1988, and 1992-1993. Rubella was non-endemic in Japan before the 1975-1977 epidemic, and endemic thereafter. Japan started a selective rubella vaccination program for junior high school girls in 1977, and universal rubella vaccination of children of both sexes in 1989. No nationwide rubella epidemics have occurred since 1994. Only three children with CRS were reported in Japan before 1964; however, many children with CRS were identified in 1965 when a rubella epidemic struck Okinawa, which has many the United States military bases. After the 1965-1969 and 1975-1977 rubella epidemics on the Japanese mainland, small numbers of children with CRS were identified (hospital survey). These findings led to the hypothesis that, compared to U.S. rubella virus strains, Japanese strains of rubella virus are less teratogenic. This hypothesis strongly affected the development of rubella vaccines in Japan. However, retrospective seroepidemiological studies attributed the CRS in many children in Okinawa to the high rate of rubella infection in pregnant women. According to the survey conducted at special schools for the deaf, 83, 232, 77, and 167 children were born with CRS on the Japanese mainland respectively after the 1965-1969, 1975-1977, 1982, and 1987-1988 nationwide rubella epidemics, suggesting that the incidence of CRS in Japan is in fact comparable to that in the U.S. and Europe. Rubella epidemics in children have been effectively prevented since 1994. However, a rubella outbreak among adult males and CRS occurred between 2012 and 2014.

[Seroepidemiological Studies on Pertussis, Diphtheria and Tetanus among Nursing Students Enrolled between 1994 and 2011 in the Kitakyushu District].

Seroepidemiological studies on pertussis, diphtheria and tetanus were performed on 1,540 nursing students enrolled in S-university between 1994 and 2011. Antibody titers against pertussis toxin (PT) and filamentous hemagglutinin (FHA), diphtheria antitoxin titer, and tetanus antitoxin titer were measured using sera taken during enrollment. The antibody-seropositive rates and geometric mean titers (GMTs) were calculated by according to birth year (1975-1993). The pertussis anti-PT and anti-FHA antibody-seropositive rates (seropositive levels were both defined as ≥10 EU/mL) were 12%-53% and 47%-84%, respectively. The anti-PT antibody-seropositive rate was lower than the anti-FHA rate. The anti-PT antibody GMTs were 2.0-11 EU/mL, whereas the anti-FHA antibody GMTs were 10 EU/mL or more (8.8-31 EU/mL) in almost every group. The diphtheria antitoxin-seropositive rate (≥0.1 IU/mL) was 49%-79%, and the GMT was nearly 0.1 IU/mL. The tetanus antitoxin-seropositive rate (≥0.01 IU/mL) was 91%-100%, and the GMT was 0.3 IU/mL or more for all the groups. While the nursing students' diphtheria and tetanus antitoxin levels were sufficient to prevent both diseases, the anti-PT antibody-seropositive rate and the GMT were both lower than the level required to prevent pertussis, suggesting that many of the nursing students were pertussis-susceptible. These findings suggest a need for pertussis vaccination in young adults or early adolescents.

A clinical phase I study of an EB66 cell-derived H5N1 pandemic vaccine adjuvanted with AS03.

BACKGROUND: We conducted a phase I clinical trial of a cell culture-derived AS03-adjuvanted influenza vaccine containing HA antigen (A/Indonesia/05/2005(H5N1)/PR8-IBCDC-RG2) derived from EB66 cells (KD-295). METHODS: Healthy male adult volunteers (20-40 years old, N=60) enrolled in the study were divided into 3 groups, the MA group (3.8 µg of HA+AS03), HA group (7.5 µg of HA+AS03), and 1/2 MA group (half the volume of the MA group), and received KD-295 intramuscularly twice with a 21-day interval. After administration of KD-295, adverse events, clinical laboratory parameters, and immune response to the vaccine strain and heterologous virus strains were evaluated. RESULTS: No severe adverse events leading to discontinuation of vaccine administration occurred. The vaccine was well-tolerated. There was no dose dependency in the rate, timing, or duration of the adverse events. Immunogenicity of the vaccines was evaluated by HI (hemagglutination inhibition) assay, which confirmed that the antibody response to the vaccine strain and heterologous strain in all groups met the three criteria for immunogenicity described in the Japanese guidelines for development of a pandemic prototype vaccine. We also measured the neutralizing antibody titers against several virus strains, and confirmed a significant rise in antibody levels to both the vaccine strain and heterologous strains. CONCLUSION: The EB66-derived H5N1 influenza vaccine adjuvanted with AS03 elicited a broad cross-reactive antibody response among H5N1 strains with acceptable reactogenicity. Therefore, KD-295 can be considered a useful pandemic and pre-pandemic influenza vaccine candidate.

Immunogenicity and safety of an inactivated quadrivalent influenza vaccine in healthy adults: a phase II, open-label, uncontrolled trial in Japan.

Two antigenically distinct B strain lineages of influenza virus have co-circulated since the mid-1980s; however, inactivated trivalent influenza vaccines contain only one B lineage. The mismatch between the circulating and vaccine lineages has been a worldwide issue. In this study, an inactivated quadrivalent influenza vaccine (QIV) candidate containing two B lineages was manufactured and its immunogenicity and safety evaluated in an open-label, uncontrolled trial. In this phase II trial, 50 subjects aged 20-64 years received two doses of QIV s.c. 1 to 4 weeks apart. Sera were collected pre- and post-vaccination and safety assessed from the first vaccination to 21 ± 7 days after the second vaccination. After the first vaccination, hemagglutination inhibition titers against each strain increased markedly; the seroconversion rate, geometric mean titer ratio and seroprotection rate being 94.0%, 24.93, and 100.0%, respectively, for the A/H1N1pdm09 strain; 94.0%, 12.47, and 98.0%, respectively, for the A/H3N2 strain; 54.0%, 4.99, and 66.0%, respectively, for B/Yamagata strain, and 72.0%, 6.23 and 80.0%, respectively, for the B/Victoria strain, thus fulfilling the criteria of the European Medical Agency's Committee for Medicinal Products for Human Use. Also, the QIV induced sufficient single radial hemolysis and neutralizing antibodies against all four vaccine strains. No noteworthy adverse events were noted. The results of this trial demonstrate that QIV is well tolerated and immunogenic for each strain, suggesting that QIV potentially improves protection against influenza B by resolving the issue of B lineage mismatch.

Phase III clinical trials comparing the immunogenicity and safety of the vero cell-derived Japanese encephalitis vaccine Encevac with those of mouse brain-derived vaccine by using the Beijing-1 strain.

The immunogenicity and safety of an inactivated cell culture Japanese encephalitis vaccine (CC-JEV) were compared with those of an inactivated mouse brain-derived Japanese encephalitis vaccine (MB-JEV) in phase III clinical multicenter trials conducted in children. The vaccines contain the same Japanese encephalitis virus strain, the Beijing-1 strain. Two independent clinical trials (trials 1 and 2) were conducted. Trial 1 was conducted in 468 healthy children. Each subject was injected with 17 µg per dose of either CC-JEV or MB-JEV, and the immunogenicity and safety of the vaccines were investigated. Trial 1 showed that CC-JEV was more immunogenic and reactive than MB-JEV at the same dose. Therefore, to adjust the immunogenicity of CC-JEV to that of MB-JEV, a vaccine that has had a good track record regarding its efficacy for a long time, trial 2 was conducted in 484 healthy children. To improve the stability, CC-JEV was converted from a liquid type to a freeze-dried type of vaccine. Each subject was injected subcutaneously with either 4 µg per dose of CC-JEV, 8 µg per dose of CC-JEV, or 17 µg per dose of MB-JEV twice, at an interval of 2 to 4 weeks, followed by an additional booster immunization 1 to 15 months after the primary immunization. Based on the results of trial 2, 4 µg per dose of the freeze-dried CC-JEV (under the label Encevac) was selected as a substitute for the MB-JEV. Encevac was approved and launched in 2011 and has since been in use as a 2nd-generation Japanese encephalitis vaccine in Japan. (These studies have been registered at the JapicCTI under registration no. JapicCTI-132063 and JapicCTI-080586 for trials 1 and 2, respectively).

Phase II and III Clinical Studies of Diphtheria-Tetanus-Acellular Pertussis Vaccine Containing Inactivated Polio Vaccine Derived from Sabin Strains (DTaP-sIPV).

BACKGROUND: Phase II and III clinical studies were conducted to evaluate immunogenicity and safety of a novel DTaP-IPV vaccine consisting of Sabin inactivated poliovirus vaccine (sIPV) and diphtheria-tetanus-acellular pertussis vaccine (DTaP). METHODS: A Phase II study was conducted in 104 healthy infants using Formulation H of the DTaP-sIPV vaccine containing high-dose sIPV (3, 100, and 100 D-antigen units for types 1, 2, and 3, respectively), and Formulations M and L, containing half and one-fourth of the sIPV in Formulation H, respectively. Each formulation was administered 3 times for primary immunization and once for booster immunization. A Phase III study was conducted in 342 healthy infants who received either Formulation M + oral polio vaccine (OPV) placebo or DTaP + OPV. The OPV or OPV placebo was orally administered twice between primary and booster immunizations. RESULTS: Formulation M was selected as the optimum dose. In the Phase III study, the seropositive rate was 100% for all Sabin strains after primary immunization, and the neutralizing antibody titer after booster immunization was higher than in the control group (DTaP + OPV). All adverse reactions were clinically acceptable. CONCLUSIONS: DTaP-sIPV was shown to be a safe and immunogenic vaccine. CLINICAL TRIALS REGISTRATION: JapicCTI-121902 for Phase II study, JapicCTI-101075 for Phase III study (http://www.clinicaltrials.jp/user/cte_main.jsp).

Immunogenicity of an inactivated adjuvanted whole-virion influenza A (H5N1, NIBRG-14) vaccine administered by intramuscular or subcutaneous injection.

The immunogenicity and safety profile of an inactivated whole-virion influenza A (H5N1, NIBRG-14) vaccine with alum adjuvant that was administered by IM or SC injection in a phase I clinical study involving 120 healthy Japanese men aged 20-40 years is described. The serological response of the IM group was stronger than that of the SC group. Local adverse events were less severe with IM injection than with SC injection, while similar systemic adverse events were seen in both groups. These results indicate that, when administering an inactivated whole virion vaccine with alum adjuvant for pandemic influenza, IM injection may achieve better immunogenicity and safety than SC injection.

Development of the rubella vaccine and vaccination strategy in Japan.

The development of the rubella vaccine and vaccination strategy in Japan was unique. Five rubella vaccines used in Japan were licensed, and the rubella vaccine program to schoolgirls was started in 1977. The measles-mumps-rubella vaccination to children which started in 1989, was terminated in 1993 due to the adverse effect of aseptic meningitis. In 1994, rubella vaccination to children, using the monovalent rubella vaccine, was restarted. Then, a new vaccination program, vaccinating twice by using the combined measles and rubella vaccine, was started in 2006. The increase in the rate of vaccination leads us to hope for the "Elimination of Rubella and Congenital Rubella Syndrome in 2012".

Duration of neutralizing antibody titer after Japanese encephalitis vaccination.

In paired serum samples collected from 17 children, we measured neutralizing antibody (NTAb) titers after the second series of routine Japanese encephalitis (JE) vaccination in Japan to estimate the duration of NTAb titer when children did not receive the third series of routine vaccination by applying a random coefficient model. We also measured NTAb titers in adult serum samples to confirm the duration of NTAb titer estimated in the analysis of pediatric serum samples. In the absence of the third series of routine vaccination, 18% (3/17), 47% (8/17), 82% (14/17) and 100% (17/17) of children were estimated to become NTAb negative at 5, 10, 15, and 20 years after the second series of routine vaccination, respectively. Of 38 adults, 39.5% (15/38) became NTAb negative; the percentage was somewhat lower than that of antibody-negative children. The results suggested that JE vaccination schedule should be reevaluated in the future.

Seroepidemiologic study on pertussis, diphtheria, and tetanus in the Fukuoka area of southern Japan: seroprevalence among persons 0-80 years old and vaccination program.

In Japan, mass vaccination for diphtheria, pertussis, and/or tetanus has been mandated by the Vaccination Law since 1948. In order to evaluate the efficacy of this vaccination policy, we conducted seroepidemiological studies on pertussis, diphtheria, and tetanus among individuals aged 0 - 80 years. The pertussis toxin seropositive rates of the vaccine-eligible groups and vaccine-ineligible groups were 55.0 and 57.9%, respectively. The seropositive rate of each group for diphtheria antitoxin was 76.3 and 75.7%, respectively. The tetanus antitoxin seropositive rates were 91.7 and 10.5%, respectively, showing a significant difference between the two groups (P < 0.001). For the three diseases, variations were seen between age groups in the geometric mean antibody titers due to changes of the vaccination program. The results of this study show that natural Bordetella pertussis infection has occurred more frequently than expected. In order to establish the most appropriate vaccination program for the control of pertussis, diphtheria, and tetanus in Japan, further evaluation is necessary.

Non-clinical and phase I clinical trials of a Vero cell-derived inactivated Japanese encephalitis vaccine.

The safety and effectiveness of a Vero cell-derived inactivated Japanese encephalitis (JE) vaccine were compared with those of a current JE vaccine in non-clinical studies and a phase I clinical trial. The single-dose toxicity study showed no toxicity of either the current JE vaccine or the investigational Vero cell-derived JE vaccine. In a local irritation study, the degree of irritation caused by both vaccines was determined to be the same as that induced by normal saline. To investigate genotoxicity, a chromosomal aberration test was conducted and the results were negative. Both JE vaccines were administered to a group of 30 subjects who were seronegative (neutralizing antibody titer <10(1)) for JEV virus (Beijing-1 Strain). Each subject was subcutaneously inoculated twice at an interval of 1-4 weeks, followed by an additional booster inoculation 4-8 weeks later, and clinical reactions and serological responses were subsequently investigated. Adverse drug reactions of local reaction, headache and malaise were mild, occurring at a rate of 6.7 and 20.0% after administration of the Vero cell-derived JE vaccine and the current JE vaccine, respectively. The seroconversion rate after three doses of both JE vaccines was 100%, while the geometric mean titer for the Vero cell-derived and current JE vaccines was 10(2.35) and 10(2.03), respectively. These results suggest that the safety and effectiveness of the Vero cell-derived inactivated JE vaccine are equal to those of the currently available conventional vaccine in humans, and that the Vero cell-derived vaccine could be a useful second-generation JE vaccine.