News from the 91st annual meeting of the American Association for Cancer Research, which is being held in San Francisco;
¿ AltaRex Corp., of Waltham, Mass., said four of its Antibody-based ImmunoTherapy antibodies demonstrated significant antitumor responses in mouse models and other experimental systems. Tests also confirmed the importance of using murine antibodies to produce a more effective antitumor response. OvaRex, BrevaRex, ProstaRex and GivaRex monoclonal antibodies were the subject of the presentation.
¿ Antisoma plc, of London, said antibody-based proteins developed in the company¿s targeted apoptosis program kill breast cancer cells, causing little or no side effects.
¿ Celgene Corp., of Warren, N.J., said preclinical results demonstrate thalidomide and its structural analogues inhibit cyclooxygenase-2 production. The COX-2 enzyme is known to play a role in inflammation and angiogenesis, which may help explain the mechanism by which these compounds operate in certain biological pathways.
¿ Cell Pathways Inc., of Horsham, Pa., and researchers from Columbia University said exisulind (Aptosyn) and other selective apoptotic antineoplastic drugs (SAANDs) inhibit the growth of prostate cancer cells by directly killing them by inducing apoptosis and by decreasing expression of the androgen receptor in the cancerous prostate cells. Researchers also demonstrated that exisulind and two other SAANDs, CP461 and CP248, inhibited the cellular expression and secretion of prostate specific antigen at the same concentrations that induced apoptosis in the cells. CP461 also was shown to significantly enhance the antitumor activity of Taxol (paclitaxel) in a classic mouse model of human breast cancer.
¿ Hybridon Inc., of Milford, Mass., and its collaborators at the University of Alabama at Birmingham presented data suggesting that MDM2 plays a role in tumor growth through both p53-dependent and p53-independent pathways. Scientists inhibited MDM2 expression using a novel antisense oligonucleotide, which demonstrated dose-dependent in vivo antitumor activity.
¿ ImClone Systems Inc., of New York, said preclinical data on its recombinant gp75 vaccine candidate in a mouse model of melanoma showed positive results. Researchers demonstrated that immunization of mice with the gp75 vaccine produced a strong immune response to the recombinant protein, as well as to natural gp75 expressed in the melanoma cells. Additional findings demonstrated that mice immunized with the vaccine had a significantly reduced number of melanoma lung metastases, as compared with controls.
¿ Magainin Pharmaceuticals Inc., of Plymouth Meeting, Pa., said a study of the company¿s anti-angiogenic agent squalamine in neuroblastoma demonstrated that squalamine inhibits tumor growth and promotes tumor shrinkage when used in combination with cisplatin in the treatment of neuroblastomas. The company expects to initiate a pediatric solid tumor clinical study later this year.
¿ Matritech Inc., of Newton, Mass., said data from a study of women using the NMP179 Test for the identification and management of cervical cancer show that the test detected 92 percent of the cases in which high-risk disease was present in specimens that initial human review had identified as being equivocal. The study involved 869 women with equivocal Pap smears.
¿ Progenics Pharmaceuticals Inc., of Tarrytown, N.Y., and Cytogen Corp., of Princeton, N.J., said researchers have developed strategies for producing novel therapeutic antibodies and vaccines that elicit robust immune responses to prostate-specific membrane antigen (PSMA), a molecular cancer marker abundantly expressed on the surface of prostate cancer cells. The program includes recombinant PSMA protein immunogens, as well as novel and proprietary viral vectors that deliver the PSMA gene to the immune system. In animal studies the vaccines have generated potent and specific immune responses to cell-surface PSMA.