1 March 2019 - - US-based pharmaceutical company Pfizer Inc. (NYSE: PFE) has included new serotypes included in its 20-Valent pneumococcal conjugate vaccine (20vPnC) candidate, PF-06482077, to be investigated for the prevention of invasive disease and pneumonia caused by Streptococcus pneumoniae serotypes covered in the vaccine in adults aged 18 years and older, the company said.

Pfizer's 20vPnC candidate includes the 13 serotypes contained in Prevnar 13 (1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F and 23F) plus 7 additional serotypes (8, 10A, 11A, 12F, 15BC, 22F and 33F).

Pfizer also announced that data from a Phase 2, proof-of-concept study of 20vPnC in adults have been accepted for oral presentation at the upcoming 29th European Congress of Clinical Microbiology and Infectious Diseases (ECCMID), which will take place in Amsterdam, Netherlands, from April 13-16, 2019.

In addition, three Phase 3 trials (NCT03828617, NCT03835975 and NCT03760146) have been initiated for the purpose of evaluating 20vPnC in adults. Combined, these three trials will enroll more than 6,000 adult subjects, including populations of vaccine-naïve adults and adults with prior pneumococcal vaccination.

All seven of the new serotypes included in 20vPnC are global causes of invasive pneumococcal disease, and six of the seven serotypes (8, 10A, 11A, 15BC, 22F and 33F) are associated with high case-fatality rates.

In addition, four of these serotypes (11A, 15B/C, 22F and 33F) are associated with antibiotic resistance and/or meningitis (10A, 15B/C, 22F and 33F).

Together, all of the 20 serotypes included in 20vPnC are responsible for the majority of currently circulating pneumococcal disease in adults in the US and globally.

Pfizer's Phase 3 pivotal development program for 20vPnC includes three clinical trials in populations of vaccine-naïve adults and adults with prior pneumococcal vaccination.

The pivotal Phase 3 trial is enrolling an estimated 3,880 adults and is designed to compare immune responses after 20vPnC administration to responses in control subjects ≥60 years old receiving 13-valent pneumococcal conjugate vaccine and 23-valent pneumococcal polysaccharide vaccine; evaluate the immunogenicity of 20vPnC in adults 18-59 years of age; and describe the 20vPnC safety profile in adults ≥18 years old.

Another Phase 3 trial was initiated on February 12, 2019 and is planned to enroll an estimated 875 adults. It is designed to describe the safety and immunogenicity of 20vPnC in adults 65 years of age or older with prior pneumococcal vaccination.

A third Phase 3 trial was initiated on February 14, 2019, and is planned to enroll an estimated 1,610 adults.

The study is designed to provide additional safety data and evaluate three different lots of 20vPnC in adults 18 through 49 years of age.

On September 20, 2018, Pfizer announced the US Food and Drug Administration granted Breakthrough Therapy Designation for 20vPnC for the prevention of invasive disease and pneumonia in adults age 18 years and older.

Breakthrough Therapy Designation is designed to expedite the development and review of drugs and vaccines that are intended to treat or prevent serious conditions and preliminary clinical evidence indicates that the drug or vaccine may demonstrate substantial improvement over available therapy on a clinically significant endpoint(s).

Drugs and vaccines that receive Breakthrough Therapy Designation are eligible for all features of the FDA's Fast Track designation, which may include more frequent communication with the FDA about the drug's development plan and eligibility for Accelerated Approval and Priority Review, if relevant criteria are met.

The FDA previously granted Fast Track designation for 20vPnC in September 2017 for use in adults aged 18 years and older.21The FDA's Fast Track approach is a process designed to facilitate the development and expedite the review of new drugs and vaccines intended to treat or prevent serious conditions and address an unmet medical need.

Additionally, in May 2017 the FDA granted Fast Track status for a pediatric indication for 20vPnC and clinical development is in progress.