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Study of a Candidate Clostridium Difficile Toxoid Vaccine in Subjects at Risk for C. Difficile Infection

Phase 3
Terminated
Conditions
Clostridium Difficile Infection
Interventions
Biological: C. difficile Toxoid Vaccine
Registration Number
NCT01887912
Lead Sponsor
Sanofi Pasteur, a Sanofi Company
Brief Summary

The aim of this study was to evaluate the efficacy of the Clostridium difficile vaccine to prevent primary symptomatic C. difficile infection (CDI) in participants at risk for CDI where there is a substantial unmet medical need.

Primary objective:

* To assess the efficacy of the C. difficile vaccine in preventing the onset of symptomatic primary CDI confirmed by polymerase chain reaction (PCR) in adult participants aged \>= 50 years who are at risk for CDI and have received at least 1 injection.

Secondary Objectives:

Efficacy:

* To assess prevention of symptomatic PCR-confirmed primary CDI cases after 3 injections administered at 0, 7, and 30 days.

* To assess prevention of symptomatic PCR-confirmed primary CDI cases after completion of at least 2 injections.

Immunogenicity:

* To describe the immunogenicity to toxin A and toxin B at specific time points in a subset of participant and in participants with CDI at Day 0 and Day 60.

Safety:

* To describe the safety profile of all participants who received at least 1 injection.

Detailed Description

The study was designed as an event-driven group sequential protocol with 4 interim analyses at defined information milestones and a final analysis when a specific number of clinical endpoints are reached. Analyses of trial futility (non-efficacy) were to be performed at the first 2 interim analyses, and the study was to be stopped if either of those analyses provided robust and compelling evidence that meaningful levels of vaccine efficacy (VE) would not be demonstrated.

Following completion of the first interim analysis (50 cases of confirmed CDI observed), the futility criterion was met and in accordance with IDMC recommendation, enrollment and further vaccination ceased in November 2017.

Due to the early termination of the study, some of the planned secondary efficacy endpoints could not be analyzed as all planned data were not collected.

Participants were randomized to receive either the candidate vaccine or a placebo that was to be administered in a 3-dose schedule. At the time of group assignment, 928 participants (10% of total enrollment) were randomized to an immunogenicity subset; and 1859 participants (20% of total enrollment) were randomized to a reactogenicity subset.

Safety was assessed in all participants in terms of unsolicited adverse events from Day 0 to Day 60, as well as serious adverse events (SAEs) throughout the study. Solicited adverse reactions were collected for 6 days following each injection in the reactogenicity subset.

Recruitment & Eligibility

Status
TERMINATED
Sex
All
Target Recruitment
9302
Inclusion Criteria
  • Aged >= 50 years on the day of inclusion
  • Informed consent form had been signed and dated.
  • Attended all scheduled visits and complied with all trial procedures.
  • Covered by health insurance (if required).
  • Must fulfill at least 1 of the following criteria

Risk Stratum 1:

  • Had at least 2 hospital stays, each lasting at least >= 24 hours, in the 12 months before enrollment, and
  • Had received systemic (not topical) antibiotics in the 12 months before enrollment, or

Risk Stratum 2:

  • Was anticipated to have an in-patient hospitalization for a planned surgical procedure within 60 days of enrollment. The impending hospital stay was planned to be >= 72 hours for a surgery involving 1 of the following:
  • Kidney/bladder/urinary system
  • Musculoskeletal system
  • Respiratory system
  • Circulatory system
  • Central nervous system.
Exclusion Criteria
  • Participant was pregnant, or lactating, or of childbearing potential (to be considered of non-childbearing potential, a female must be post-menopausal for at least 1 year, surgically sterile, or using an effective method of contraception or abstinence from at least 4 weeks prior to the first vaccination and until at least 4 weeks after the last vaccination).
  • Participation in the 4 weeks preceding the first trial vaccination or participation during the present trial period in another clinical trial investigating a vaccine, drug, medical device, or medical procedure.
  • Receipt of any vaccine in the 4 weeks preceding the first trial vaccination except for influenza (seasonal or pandemic) and pneumococcal vaccines. This exception includes monovalent pandemic influenza vaccines and multivalent influenza vaccines.
  • Previous vaccination against C. difficile with either the trial vaccine, another vaccine, or monoclonal antibodies.
  • Diarrhea on day of enrollment.
  • Self-reported current or prior CDI episode.
  • Anticipated or current receipt of kidney dialysis treatment.
  • History of gastrointestinal surgery for gastrointestinal malignancy (Note: Colonoscopy, polypectomy, and appendectomy are not exclusion criteria).
  • History of inflammatory bowel disease, irritable bowel syndrome (must include diarrhea as a symptom), colostomy, or small or large intestine bowel surgery where resection was performed.
  • Receiving enteral feeding (e.g., nasogastric, gastrostomy, and jejunostomy tube feeding).
  • Known or suspected congenital or acquired immunodeficiency; or receipt of immunosuppressive therapy, such as anti-cancer chemotherapy or radiation therapy, within the preceding 6 months; or long-term systemic corticosteroid therapy (prednisone or equivalent for more than 2 consecutive weeks within the past 3 months).
  • Known systemic hypersensitivity to any of the vaccine components, or history of a life-threatening reaction to the vaccine used in the trial or to a vaccine containing any of the same substances.
  • Self-reported thrombocytopenia, contraindicating intramuscular vaccination.
  • Deprived of freedom by an administrative or court order, or in an emergency setting, or hospitalized involuntarily.
  • Current alcohol abuse or drug addiction that might interfere with the ability to comply with trial procedures in the opinion of the Investigator.
  • Chronic illness that, in the opinion of the investigator, is at a stage where it might interfere with trial conduct or completion.
  • Moderate or severe acute illness/infection (according to investigator judgment) on the day of vaccination or febrile illness (temperature >= 38.0 degree Celsius [>= 100.4°Fahrenheit]). A prospective participant should not be included in the study until the condition has resolved or the febrile event has subsided.
  • Identified as an Investigator or employee of the Investigator or study center with direct involvement in the proposed study, or identified as an immediate family member (i.e., parent, spouse, natural or adopted child) of the Investigator or employee with direct involvement in the proposed study.

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
C. difficile Vaccine GroupC. difficile Toxoid VaccineParticipants received 1 injection of 0.5 mL C. difficile toxoid vaccine at Days 0 (Injection 1), 7 (Injection 2), and 30 (Injection 3).
Primary Outcome Measures
NameTimeMethod
Number of Participants With Symptomatic Polymerase Chain Reaction (PCR)-Confirmed Primary C. Difficile Infection (CDI) CasesUp to 3 years post injection 1

Symptomatic PCR-confirmed CDI cases were defined as the number of participants with combination of clinical and laboratory findings. Clinical components were: \>= 3 loose stools in \<= 24 hours, loose stools (defined as type 6 \[fluffy pieces with ragged edges, mushy\] or type 7 \[watery, no solid pieces\] according to the Bristol Stool Chart) lasting \>= 24 hours. Laboratory findings were: stool sample positive for C. difficile Toxin B by PCR at central laboratory or diagnosis of pseudomembranous colitis visualized at colonoscopy.

Secondary Outcome Measures
NameTimeMethod
Number of Participants With Severe PCR-Confirmed Primary CDI CasesUp to 3 years post injection 1

Severe CDI cases were defined as number of participants with at least one of the following symptoms: fever \>= 38.5 degree Celsius (°C), white blood cell count \>= 15,000 cells/mm\^3, ileus, pseudomembranous colitis, serum albumin \<3 gram per deciliter, abdominal distension, abdominal tenderness, or admission to the intensive care unit within 7 days of CDI diagnosis.

Number of Participants With Loose Stool EpisodesUp to 3 years post injection 1

Loose stools were defined as type 6 (fluffy pieces with ragged edges, mushy) or type 7 (watery, no solid pieces) according to the Bristol Stool Chart. In this outcome measure, participants with number of loose stool episodes (categorized as: loose stool episodes less than 3, 3 to 6, 7 to 10, 11 to 15 and greater than 15) were reported.

Number of Participants With Symptomatic PCR Confirmed CDI Cases: Per-Protocol PopulationUp to 3 years post injection 1

Symptomatic PCR confirmed CDI cases were defined as the number of participants with combination of clinical and laboratory findings. Clinical components were: \>= 3 loose stools in \<= 24 hours, loose stools (defined as type 6 \[fluffy pieces with ragged edges, mushy\] or type 7 \[watery, no solid pieces\] according to the Bristol Stool Chart) lasting \>= 24 hours. Laboratory findings were: stool sample positive for C. difficile Toxin B by PCR at central laboratory or diagnosis of pseudomembranous colitis visualized at colonoscopy. Analysis was performed on per-protocol efficacy analysis set (PPEAS).

Serum Antibody Concentrations Against Toxins A and B Measured by Toxin Neutralization Assay (TNA)Day 0, Day 14, Day 30, Day 60, Day 210, Day 390, Day 570, Day 750, Day 930, and Day 1110

Serum antibody concentrations against toxins A and B were measured by TNA and expressed as geometric mean titer (GMT). The 2-sided 95% Cl of GMT was based on the Student t-distribution.

Serum Antibody Concentrations Against Toxins A and B Measured by TNA in Participants With CDIDay 0 and Day 60

Serum antibody concentrations against toxins A and B were measured by TNA and were expressed as GMT. The 2-sided 95% CI GMC was based on the Student t-distribution. Symptomatic PCR confirmed CDI cases were defined as the number of participants with combination of clinical and laboratory findings. Clinical components were: \>= 3 loose stools in \<= 24 hours, loose stools (defined as type 6 \[fluffy pieces with ragged edges, mushy\] or type 7 \[watery, no solid pieces\] according to the Bristol Stool Chart) lasting \>= 24 hours. Laboratory findings were: stool sample positive for C. difficile Toxin B by PCR at central laboratory or diagnosis of pseudomembranous colitis visualized at colonoscopy.

Percentage of Participants With >= 2 and 4-Fold Rise in Serum Antibody Concentrations From Baseline Against Toxins A and B Measured by ELISADay 60

Percentage of Participants with \>= 2 and 4-fold rise in serum antibody concentrations against toxins A and B were measured by ELISA. The 2-sided 95% Cl of the percentage was based on Exact method calculations.

Serum Antibody Concentrations Against Toxins A and B Measured by Enzyme-Linked Immunosorbent Assay (ELISA)Day 0, Day 14, Day 30, Day 60, Day 210, Day 390, Day 570, Day 750, Day 930, and Day 1110

Serum antibody concentrations against toxins A and B were measured by ELISA and expressed as geometric mean concentration (GMC). The 2-sided 95% Confidence Interval (CI) of GMC was based on the Student t-distribution. Analysis was performed on Per Protocol Immunogenicity Analysis Set, which included participants who had at least 1 injection, no relevant protocol deviations (not met inclusion criteria/ met exclusion criteria, not received vaccine/ not received in proper time window, received different vaccine than randomized, preparation and/ or administration of vaccine not per protocol, protocol-restricted therapy, not provided post-dose serology sample/serology sample did not produced a valid test result).

Serum Antibody Concentrations Against Toxins A and B Measured by ELISA in Participants With CDIDay 0 and Day 60

Serum antibody concentrations against toxins A and B were measured by ELISA and expressed as GMC. The 2-sided 95% CI GMC was based on the Student t-distribution. Symptomatic PCR-confirmed CDI cases were defined as the number of participants with combination of clinical and laboratory findings. Clinical components were: \>= 3 loose stools in \<= 24 hours, loose stools (defined as type 6 \[fluffy pieces with ragged edges, mushy\] or type 7 \[watery, no solid pieces\] according to the Bristol Stool Chart) lasting \>= 24 hours. Laboratory findings were: stool sample positive for C. difficile Toxin B by PCR at central laboratory or diagnosis of pseudomembranous colitis visualized at colonoscopy.

Percentage of Participants With >= 2 and 4-Fold Rise in Serum Antibody Concentrations From Baseline Against Toxins A and B Measured by TNADay 60

Percentage of Participants with \>= 2 and 4-fold rise in serum antibody concentrations against toxins A and B were measured by TNA. The 2-sided 95% CI of the percentage was based on Exact method calculations.

Percentage of Participants Reporting Solicited Injection Site and Systemic ReactionsDay 0 to Day 6 after any vaccination

Solicited injection site reactions: pain, erythema, and swelling. Pain: Grade 1: no interference with activity, Grade 2: some interference with activity, Grade 3: significant; prevents daily activity; Erythema and swelling: Grade 1: \>= 25 to \<=50 mm, Grade 2: \>51 to \<=100 mm, Grade 3: \>100 mm. Solicited systemic reactions: fever, headache, malaise, myalgia, and arthralgia. Fever: Grade 1: \>= 38.0°C to \<=38.4°C or \>= 100.4° Fahrenheit (F) to \<=101.1°F, Grade 2: \>=38.5°C to \<= 38.9°C or \>=101.2°F to \<=102.0°F, Grade 3: \>=39.0°C or \>=102.1°F. Headache, malaise, and myalgia: Grade 1: no interference with activity, Grade 2: some interference with activity, Grade 3: significant; prevents daily activity; Arthralgia: Grade 1: free range of motion but complains of pain or discomfort, Grade 2: decreased range of motion due to pain or discomfort, Grade 3: unwilling to move due to pain.

Trial Locations

Locations (155)

Investigational Site 020

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Wilkes-Barre, Pennsylvania, United States

Investigational Site 180

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Spartanburg, South Carolina, United States

Investigational Site 104

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Mobile, Alabama, United States

Investigational Site 534

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Los Angeles, California, United States

Investigational Site 051

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Los Angeles, California, United States

Investigational Site 143

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Bradenton, Florida, United States

Investigational Site 055

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Crystal River, Florida, United States

Investigational Site 075

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Clearwater, Florida, United States

Investigational Site 517

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Clearwater, Florida, United States

Investigational Site 149

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Augusta, Georgia, United States

Investigational Site 099

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Hialeah, Florida, United States

Investigational Site 529

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Decatur, Georgia, United States

Investigational Site 010

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Savannah, Georgia, United States

Investigational Site 049

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Idaho Falls, Idaho, United States

Investigational Site 077

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Shreveport, Louisiana, United States

Investigational Site 183

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Flint, Michigan, United States

Investigational Site 146

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Asheville, North Carolina, United States

Investigational Site 003

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Columbus, Ohio, United States

Investigational Site 002

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Boston, Massachusetts, United States

Investigational Site 193

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San Antonio, Texas, United States

Investigational Site 365

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Piura, Peru

Investigational Site 441

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Khon Kaen, Thailand

Investigational Site 354

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Panama City, Panama

Investigational Site 443

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Bangkok, Thailand

Investigational Site 426

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New Taipei City, Taiwan

Investigational Site 194

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Phoenix, Arizona, United States

Investigational Site 232

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Tours, France

Investigational Site 223

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St Priest en Jarez, France

Investigational Site 151

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Sherbrooke, Quebec, Canada

Investigational Site 161

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Trois-Rivières, Quebec, Canada

Investigational Site 454

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Kyoto, Japan

Investigational Site 467

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Shimonoseki, Japan

Investigational Site 457

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Gunma, Japan

Investigational Site 460

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Kyoto, Japan

Investigational Site 458

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Nagano, Japan

Investigational Site 456

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Nagano, Japan

Investigational Site 469

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Okinawa, Japan

Investigational Site 459

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Saitama, Japan

Investigational Site 451

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Tokyo, Japan

Investigational Site 463

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Yamaguchi, Japan

Investigational Site 461

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Ōsaka, Japan

Investigational Site 203

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Järvenpää, Finland

Investigational Site 202

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Turku, Finland

Investigational Site 450

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Aichi, Japan

Investigational Site 229

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Pringy, France

Investigational Site 465

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Fukuoka, Japan

Investigational Site 215

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Aarhus, Denmark

Investigational Site 030

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Marshfield, Wisconsin, United States

Investigational Site 119

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Fort Worth, Texas, United States

Investigational Site 080

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Salt Lake City, Utah, United States

Investigational Site 401

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Cairns, Queensland, Australia

Investigational Site 156

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Surrey, British Columbia, Canada

Investigational Site 347

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Santo Domingo, Dominican Republic

Investigational Site 006

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Dallas, Texas, United States

Investigational Site 158

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Vancouver, British Columbia, Canada

Investigational Site 244

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Deggingen, BW, Germany

Investigational Site 245

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Hamburg, Germany

Investigational Site 455

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Hyōgo, Japan

Investigational Site 242

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Wurzburg, Bayern, Germany

Investigational Site 468

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Chiba, Japan

Investigational Site 453

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Ibaraki, Japan

Investigational Site 152

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Québec, Quebec, Canada

Investigational Site 012

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Lynchburg, Virginia, United States

Investigational Site 196

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Winchester, Virginia, United States

Investigational Site 201

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Tampere, Finland

Investigational Site 403

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Clayton, Victoria, Australia

Investigational Site 230

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Dijon, France

Investigational Site 221

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Paris, France

Investigational Site 247

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Hamburg, Germany

Investigational Site 415

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Seoul, Korea, Republic of

Investigational Site 413

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Ansan, Gyeonggi-do, Korea, Republic of

Investigational Site 324

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Guadalajara, Jalisco, Mexico

Investigational Site 364

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Trujillo, La Libertad, Peru

Investigational Site 464

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Fukuoka, Japan

Investigational Site 427

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Incheon, Namdong-gu, Korea, Republic of

Investigational Site 446

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Busan, Korea, Republic of

Investigational Site 466

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Fukuoka, Japan

Investigational Site 452

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Nagano, Japan

Investigational Site 409

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Seoul, Korea, Republic of

Investigational Site 407

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Wŏnju, Gangwon-do, Korea, Republic of

Investigational Site 412

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Incheon, Korea, Republic of

Investigational Site 325

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Mexico City, D.f., Mexico

Investigational Site 439

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Gyeonggi-do, Korea, Republic of

Investigational Site 408

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Seoul, Korea, Republic of

Investigational Site 411

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Seoul, Korea, Republic of

Investigational Site 437

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Seoul, Korea, Republic of

Investigational Site 329

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Mexico City, D.f., Mexico

Investigational Site 352

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Ecatepec, Estado De Mexico, Mexico

Investigational Site 326

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Durango, Mexico

Investigational Site 294

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Cordoba, Spain

Investigational Site 351

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Cuernavaca, Morelos, Mexico

Investigational Site 334

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San Martín de Porres, Lima, Peru

Investigational Site 332

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Jesus Maria, Lima, Peru

Investigational Site 356

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Lima, Peru

Investigational Site 355

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Lima, Peru

Investigational Site 283

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Nowy Duninów, Poland

Investigational Site 419

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Singapore, Singapore

Investigational Site 428

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Singapore, Singapore

Investigational Site 445

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Singapore, Singapore

Investigational Site 171

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Bayamon, Puerto Rico

Investigational Site 363

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Ciudad Victoria, Tamaulipas, Mexico

Investigational Site 425

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Taipei, Taiwan

Investigational Site 293

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Santander, Spain

Investigational Site 429

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Taichung City, Taiwan

Investigational Site 281

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Leeds, United Kingdom

Investigational Site 421

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Tainan, Taiwan

Investigational Site 442

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Bangkok, Thailand

Investigational Site 275

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Penzance, United Kingdom

Investigational Site 276

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Blackpool, United Kingdom

Investigational Site 277

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Coventry, United Kingdom

Investigational Site 271

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London, United Kingdom

Investigational Site 438

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Seoul, Korea, Republic of

Investigational Site 418

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Seoul, Korea, Republic of

Investigational Site 404

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Bedford Park, South Australia, Australia

Investigational Site 163

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Truro, Nova Scotia, Canada

Investigational Site 190

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Ann Arbor, Michigan, United States

Investigational Site 057

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Stanford, California, United States

Investigational Site 503

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Surprise, Arizona, United States

Investigational Site 504

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Simi Valley, California, United States

Investigational Site 546

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Wheat Ridge, Colorado, United States

Investigational Site 176

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Upland, California, United States

Investigational Site 187

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Brandon, Florida, United States

Investigational Site 009

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Jacksonville, Florida, United States

Investigational Site 112

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Pensacola, Florida, United States

Investigational Site 040

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Saint Petersburg, Florida, United States

Investigational Site 088

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Sarasota, Florida, United States

Investigational Site 114

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Saint Petersburg, Florida, United States

Investigational Site 543

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Pocatello, Idaho, United States

Investigational Site 101

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Iowa City, Iowa, United States

Investigational Site 091

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Metairie, Louisiana, United States

Investigational Site 035

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West Roxbury, Massachusetts, United States

Investigational Site 175

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Detroit, Michigan, United States

Investigational Site 189

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Hillsborough, New Jersey, United States

Investigational Site 069

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Royal Oak, Michigan, United States

Investigational Site 044

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Neptune, New Jersey, United States

Investigational Site 022

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Endwell, New York, United States

Investigational Site 031

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Fargo, North Dakota, United States

Investigational Site 129

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Cleveland, Ohio, United States

Investigational Site 523

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Canton, Ohio, United States

Investigational Site 061

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Dayton, Ohio, United States

Investigational Site 095

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Middletown, Ohio, United States

Investigational Site 083

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Uniontown, Pennsylvania, United States

Investigational Site 050

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Pawtucket, Rhode Island, United States

Investigational Site 086

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Rapid City, South Dakota, United States

Investigational Site 047

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Mount Pleasant, South Carolina, United States

Investigational Site 135

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Orem, Utah, United States

Investigational Site 284

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Bydgoszcz, Poland

Investigational Site 292

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Terrassa, Spain

Investigational Site 295

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Vigo, Spain

Investigational Site 540

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Charleston, South Carolina, United States

Investigational Site 084

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New Orleans, Louisiana, United States

Investigational Site 506

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Gainesville, Florida, United States

Investigational Site 013

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Bronx, New York, United States

Investigational Site 544

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Austin, Texas, United States

Investigational Site 528

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Camp Hill, Pennsylvania, United States

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