A load dose of antibodies injected in homologous species are expected to remain in circulation at fair titers for a period of 4–6 weeks based on the decay rate of biological half-life of antibodies of 3 weeks. Furthermore, the amount required for interception of implantation would be modest at this stage as only a limited number of embryonic cells make hCG. Thus, only a small volume www.selleckchem.com/products/Neratinib(HKI-272).html of high titer recombinant antibodies would be needed to ward off pregnancy. Repeated intercourses often occur during holidays. Two- to four-week vacations are given officially to all in France and in many other countries of Europe. Labor hailing from rural areas working
in cities go back home for about a month each year. A single injection can take care of worries following planned or unplanned intercourses. The dependence of early pregnancy on corpus luteum support is reported to be for 7–9 weeks.36 This seemingly banal use of antibodies find more for a process easily performed in clinics can be useful in societies (and countries) where medical termination of pregnancy (MTP) is not legal. It can be practiced in remote villages where no hospitals exist. Also it offers privacy to affected women, who
do not wish to continue with an accidental or unwanted pregnancy. Scientific evidence for termination of early pregnancy by anti-hCG antibodies is available from studies in baboons.37 Interestingly, hCG made by trophoblasts of implanted embryo stimulates the production of progesterone by the ovarian corpus luteum, which is vital for sustenance of gestation. Interruption of this process by anti-hCG antibodies would result in termination of pregnancy. The remarkable work of Köhler and Milstein38 ushered in the era of monoclonal antibodies, which are homogeneous, and of consistent affinity for binding a given epitope. Cloned hybridoma cells secrete very high titers of pure antibody in culture. Mouse monoclonals are at present precious agents for immunoassays and diagnostic kits. Although approved by regulatory
agencies for use in humans for therapeutic purposes in earlier years, such as Orthoclone (anti-CD3), LymphoCide (anti-CD22), and Panorex 17-1A (anti-EpCAM), their repeated Aspartate use is contra-indicated owing to the formation of anti-mouse antibodies in humans (HAMA). Humanization of mouse monoclonals has been achieved in more than one laboratories. Replacement of mouse constant regions in antibody chains by human IgG and kappa/lambda and its fusion with mouse variable fragments (Fab) preserves the antigen binding region of the mouse monoclonal, giving rise to chimeric (human–mouse) antibodies, which are approved by USFDA and many other Drugs Regulatory Authorities for therapeutic use in humans. We reported several years ago the development of a monoclonal antibody PiPP, against hCG,39 which had high affinity for binding hCG (Ka = 3 × 1010m−1). It was devoid of reactivity with human FSH and TSH and had <5% cross-reaction with hLH.