The Sabin Vaccine Institute (Sabin) has released updates on its product development partnership (Sabin PDP) and five Phase 1 clinical trials for two vaccine candidates for human hookworm, one of the most common neglected tropical diseases (NTDs).

These studies would not have been possible without broad collaboration across organizations and disciplines. Funding was provided by the Bill & Melinda Gates Foundation, the Dutch Ministry of Foreign Affairs and the European Commission FP7 Programme. The Infectious Disease Research Institute (IDRI), based in Seattle, manufactured the GLA-AF and CpG ODN 10104 adjuvants used in the trials. The CpG ODN 10104 adjuvant was originally developed by Pfizer. Aeras, based in Rockville, Md., manufactured the Na-GST-1 hookworm vaccine used in the studies, while Fraunhofer, based in Newark, Del., and the Walter Reed Army Institute of Research, based in Rockville, Md., manufactured the Na-APR-1 (M74) hookworm vaccine antigen.

  • Na-APR-1 (M74)/Alhydrogel® +/- GLA-AF Adjuvant in Healthy Adults (U.S.) - The trial began in September 2013 and was completed in June 2015. It was designed to evaluate the safety and immune response to Na-APR-1 (M74) in healthy adult volunteers when administered with or without the GLA-AF adjuvant. A total of 40 volunteers were vaccinated during the trial at the George Washington Medical Faculty Associates in Washington, D.C. To date, the vaccine has been well tolerated without vaccine-related serious adverse events. More information on the study is available here.
  • Na-GST-1/Alhydrogel® +/- GLA-AF Adjuvant in Healthy Adults (U.S.) - The trial began in May 2012 and was completed in January 2015. It was designed to evaluate the safety and immune response to Na-GST-1/Alhydrogel® when administered with or without the GLA-AF adjuvant. A total of 40 healthy adult volunteers were vaccinated during the trial at the Children's National Medical Center in Washington, D.C. To date, the vaccine has been well tolerated without vaccine-related serious adverse events. More information on the study is available here.
  • Na-GST-1/Alhydrogel® +/- CpG ODN 10104 Adjuvant in Healthy Adults (U.S.) - The trial began in October 2014 and is expected to be completed in May 2016. It is evaluating the safety and immune response to Na-GST-1 in healthy adult volunteers when administered with or without the CpG ODN 10104 adjuvant. A total of 24 volunteers are being vaccinated during the trial at George Washington Medical Faculty Associates in Washington, D.C. More information on the study is available here.
  • Na-GST-1/Alhydrogel® +/- GLA-AF Adjuvant in Healthy Adults (Brazil) - The trial began in November 2011 and was completed in August 2014. It was designed to evaluate the safety and immune response to Na-GST-1/Alhydrogel® when administered with or without the GLA-AF adjuvant, first in hookworm-naïve adults using an open-label design, and then in adults living in an area of endemic hookworm infection using a randomized, double-blind design. A total of 102 volunteers were vaccinated during the trial in Belo Horizonte and Americaninhas, Minas Gerais, Brazil. To date, the vaccine has been well tolerated without vaccine-related serious adverse events. Collaborating partners include the George Washington University; and the Centro de Pesquisas René Rachou, a regional unit of the Oswaldo Cruz Foundation (FIOCRUZ) of the Brazilian Ministry of Health. More information on the study is available here.
  • Na-GST-1/ Alhydrogel® Co-administered with Na-APR-1 (M74)/Alhydrogel® in Healthy Adults (Gabon) - The trial began in November 2014 and is expected to be completed in July 2016. The study is evaluating the safety and immune response to co-administered Na-GST-1 and Na-APR-1 (M74) vaccines with the GLA-AF adjuvant in healthy Gabonese adults living in an area of endemic hookworm infection. A total of 32 volunteers are being vaccinated during the trial at the Centre de Recherche Médicales de Lambaréné (CERMEL) in Lambaréné, Gabon, through the HOOKVAC consortium. More information on the study is available here.

"These studies bring us closer to developing a long-term, low-cost solution to combatting a disease that infects approximately 440 million people worldwide, and threatens the health of millions more," said David Diemert, MD, director of clinical trials of the Sabin PDP and associate professor at The George Washington University in Washington DC. "We hope these trials will lead to the development of a safe and efficacious hookworm vaccine, which, in combination with standard mass drug administration, would help to effectively control and prevent hookworm infection in endemic areas."

Hookworm is an intestinal parasite most commonly found in tropical and subtropical climates worldwide, particularly in Africa and Latin America. Hookworm is one of three members of a family of parasites known as the soil-transmitted helminths (STHs). Left untreated, hookworm causes internal blood loss leading to iron-deficiency anemia and protein malnutrition, particularly in pregnant women and children. Chronic hookworm infection in children contributes to physical and intellectual impairment, learning difficulties and poor school performance.

"A recent Global Burden of Disease study estimates almost half a billion people are infected with hookworm, indicating that it is one of the most ubiquitous infections of the poor," said Peter Hotez, MD, PhD, president of Sabin, director of the Sabin Vaccine Institute PDP and dean of the National School of Tropical Medicine at Baylor College of Medicine. "A vaccine to combat human hookworm would be an important technological breakthrough in global efforts to prevent serious health issues such as iron-deficiency anemia (IDA). In particular, success in the clinical testing of the human hookworm vaccine in Gabon and Brazil could lead to the development of the first vaccine that specifically targets IDA in low- and middle-income countries, where hookworm infection is widespread."

The Sabin PDP is based at Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development at Baylor College of Medicine in Houston, Texas.