By Donald Zuhn --
SinoBiomed announced today that the U.S. Patent & Trademark Office has issued U.S. Patent No. 7,101,556, which is directed to fusion proteins comprising the Plasmodium merozoite surface protein-1 (MSP1) and the Plasmodium apical membrane antigen 1 (AMA-1) and the production of anti-malarial vaccines using such proteins. In its release, SinoBiomed states that the '556 patent covers the malaria vaccine PfCP2.9, the exclusive rights to which SinoBiomed acquired through its subsidiary, Shanghai Wanxing Bio-pharmaceuticals Co. Ltd. Shanghai Wanxing Bio-pharmaceuticals had previously acquired the rights to the '556 patent from assignee Second Military Medical University.
Although the '556 patent issued last fall, SinoBiomed's statement is likely timed to coincide with news that its PfCP2.9 vaccine had been approved for Phase II clinical trials to be conducted in Ghana this summer by the Chinese State Food and Drug Administration (SFDA) - which SinoBiomed notes has a drug approval process similar to that of the U.S. FDA. In Phase I clinical trials, the vaccine, which targets the malaria parasite Plasmodium falciparum during its replication stage in human red blood cells, showed greater immunogenicity and fewer adverse reactions than other malaria candidate vaccines being tested. The Shanghai-based biotech company is developing and testing the vaccine with the support of the World Health Organization (WHO), the Malaria Vaccine Initiative (MVI) of the Program for the Appropriate Technology in Health (PATH), and the Bill & Melinda Gates Foundation, the latter of which has committed $258.3 million to the global fight to eradicate malaria.
The possible impact of SinoBiomed's research becomes clear when one learns that malaria threatens more than 2 billion people globally and kills more than a million people a year - most of whom are children. Further complicating matters is the fact that the treatment and control of malaria has become more difficult with the spread of drug-resistant strains of parasites and insecticide-resistant strains of mosquito vectors.
The '556 patent issued from U.S. Application No. 10/467,198 and claims the benefit of International Application PCT/CN02/00049, filed February 1, 2002, and Chinese Patent Application No. 01 1 05292, filed Feb 1, 2001. Representative independent claims 1 and 9 of the '556 patent recite:
1. A fusion protein comprising:
an amino acid sequence of Plasmodium apical membrane antigen-1 (AMA-1), an amino acid sequence of Plasmodium merozoite surface protein 1 (MSP1), and a hinge between the amino acid sequence of the apical membrane antigen-1 and the amino acid sequence of the merozoite surface protein 1,
wherein the amino acid sequence of AMA-1 is selected from the group consisting of the amino acid sequence of natural full-length AMA-1, the amino acid sequence of the whole ectodomain of AMA-1, the amino acid sequence of domain III of AMA-1, and the amino acid sequence of domain I-III of AMA-1; and
the amino acid sequence of MSP1 is selected from the group consisting of the amino acid sequence of natural full-length MSP1 and the amino acid sequence of MSP1 19KD C-terminal;
the hinge comprising an amino acid sequence selected from the group consisting of:
(a) an amino acid sequence containing 6 amino acids comprising hydrophobic amino acids Gly and Pro;
(b) an amino acid sequence encoded by multiple cloning sites; and
(c) a combination of (a) and (b).
9. A method for producing a polyclonal antibody, which inhibits the growth of P. falciparum in vitro, comprising the following steps:
(i) administering the fusion protein of claim 1 to an animal, thereby inducing the generation of a polyclonal antibody; and
(ii) isolating the polyclonal antibody.
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