The American Association for Cancer Research's annual meeting in Los Angeles ended Wednesday. Following is a summary of some of the information presented.

• Abraxis BioScience Inc., of Schaumburg, Ill., presented data from two preclinical studies that supported the role of SPARC (secreted protein acidic and rich in cysteine) expression in cancer and its nanoparticle albumin-bound (nab) tumor-targeting technology. One study demonstrated that SPARC is an albumin-binding protein and that the level of the SPARC expression could be correlated with the response of tumors to nab-paclitaxel. That supported the earlier hypothesis that higher levels of SPARC protein may lead to enhanced antitumor effect of nab-paclitaxel, which is marketed in the U.S. as Abraxane for Injectable Suspension (paclitaxel protein-bound particle for injection). The second study identified a novel spliced variant of the SPARC gene that differed from known human SPARC mRNA sequence by a single amino acid residue. The company also presented first-time data from a preclinical study evaluating the toxicity and antitumor effect of nab-rapamycin (ABI-009), an albumin-bound mTOR kinase inhibitor. Results demonstrated that nab-rapamycin was well tolerated, showed linear pharmacokinetics and was highly effective against a number of tumor models in vivo.

• Aeolus Pharmaceuticals Inc., of Laguna Niquel, Calif., and three partners presented data showing that one of the company's metalloporphyrin antioxidants, AEOL 10113, demonstrated protection of healthy normal cells in mice with prostate tumor cells treated with radiation therapy. The study also showed that the compound did not interfere with the tumor destruction effects of the radiation therapy. Researchers reported a statistically significant decrease in tumor growth in animals that received radiation alone (p<0.05, days 9, 11-14); and in animals that received radiation plus drug (p<0.05, days 11-15). Survival was improved in the radiation plus drug group with 15 percent of the mice surviving seven and nine days longer compared to radiation only and drug only groups, respectively. The researchers, from Loma Linda University Medical Center, National Jewish Medical and Research Center and Duke University, concluded that AEOL 10113 did not protect tumor response to radiation and there were no drug-related toxicities detected.

• EntreMed Inc., of Rockville, Md., presented preclinical results for MKC-1, its cell cycle inhibitor. The data showed it disrupts multiple survival pathways in tumor cells, including the PI3-Kinase and mTOR signaling pathways, and causes cell cycle arrest and induces apoptosis both in leukemia cell lines and in leukemia patient samples. MKC-1 is an orally active cell cycle inhibitor with in vitro and in vivo efficacy against solid tumor cell lines, including multidrug-resistant lines. MKC-1 has been shown to inhibit mitotic spindle formation, prevent chromosome segregation in the M-phase (mitosis) of the cell cycle and induce apoptosis. Those effects are consistent with mechanisms resulting from MKC-1 binding to multiple intracellular targets, including tubulin and the importin-beta proteins. It showed potent, dose-dependent activity against a variety of cell lines derived from cancers of human blood cells, and inhibited growth of primary cells derived from acute and chronic myelogenous leukemia patients in vitro. MKC-1 was also shown to inhibit PI3-Kinase and mTOR pathways by inducing a dose-dependent reduction in the levels of the activated forms of the oncogenic kinases Akt and p70S6K. Those signaling pathways are strongly linked to cancer proliferation and survival.

• Epigenomics AG, of Frankfurt, Germany, presented data from its colorectal cancer screening test development program showing that a modification of the assay procedure and rules for test result interpretation significantly improved the performance of its DNA-Methylation biomarker Septin 9 for the early detection of colorectal cancer in blood plasma. Using those modifications Septin 9 detected 70 percent (91 out of 130) of the colorectal cancers in the study and was falsely positive in only 10 percent (19 out of 183) of the cancer-free controls. When specificity was set at 97 percent (3 percent false-positive rate in the non-cancerous controls), 63 percent of cancers were reliably detected. Also, a 70 percent cancer detection rate was achieved in individuals found to have earlier-stage disease (stage I-III, 75 out of 107). Epigenomics now is focusing on streamlining and simplifying the assay procedure to cut test costs and improve ease of use.

• Spectrum Pharmaceuticals Inc., of Irvine, Calif., presented data from an open-label Phase IIb trial of EOquin in 23 noninvasive bladder cancer patients. It showed a single, intravesical dose was well tolerated and not systemically absorbed. The company is planning a Phase III trial. It also presented data showing the platinum-based agent satraplatin is synergistic with erlotinib (Tarceva), which may be related to changes in signaling, especially the p-Erk pathway; and that researchers concluded that SPI (IRL)-1620, a selective ETB receptor agonist, significantly enhanced the efficacy of radiation treatment in mice.

• SuperGen Inc., of Dublin, Calif., presented data showing that its multi-targeted tyrosine kinase inhibitor MP470 suppresses the Rad51 protein, a component of double-stranded DNA repair in cancer cells. Other findings presented included data pertaining to the improved bioavailability and tolerability of the hydrochloride salt of MP470 as compared to the free base. Data also were presented demonstrating its CLIMB technology and drug-discovery process to facilitate lead development and the design of several small-molecule inhibitors, including Axl kinase, as well as inhibitors of Jak2.

• VioQuest Pharmaceuticals Inc., of Basking Ridge, N.J., presented data from preclinical studies of VQD-002, a direct inhibitor of Akt activation. Data showed the compound, in combination with another targeted pathway inhibitor, roscovatine, repressed the growth of specific prostate cancer cells in vitro. The combination appeared to induce apoptosis.