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Reovirus Strain Shows Promise As An Anti-Myeloma Agent In Preclinical Study – Canadian researchers recently found that a specific strain of the reovirus may be an effective therapy for depleting residual multiple myeloma cells from stem cells collected for stem cell trans­planta­tion. Specifically, the researchers found that the virus was able to kill multiple myeloma cells in human stem cell samples without affecting the healthy blood stem cells.  The researchers took human stem cell samples, added multiple myeloma cells to get a tumor burden of 2 percent to 6 percent, incubated the samples with either live or dead reovirus, and trans­planted the stem cells into immuno­com­pro­mised mice.  All of the mice trans­planted with stem cells incubated with the dead virus developed myeloma, while none of the mice trans­planted with stem cells incubated with the live virus showed any signs of multiple myeloma. Reoviruses are typically found in the lungs and gastrointestinal tracts of animals.  Many are not associated with any known illness.  Previous studies have found that reovirus strains can selectively target and destroy cancer cells, while simultaneously triggering an immune response that helps destroy additional cancer cells. The reovirus strain tested in the Canadian study, reovirus serotype 3 (strain Dearing), also goes by the brand name Reolysin.  It is under development by the company Oncolytics Biotech, and is currently being studied in a Phase 1 clinical trial as a monotherapy for relapsed or refractory multiple myeloma.  For more in­for­ma­tion, please refer to the study in the journal Bone Marrow trans­plantation (abstract).

CD44 May Be A Good Indicator Of Revlimid Resistance In Myeloma – Findings from a recent preclinical study conducted at M. D. Anderson indicate that the protein CD44 may be a good marker of Revlimid (lena­lidomide) resistance in multiple myeloma. In particular, the researchers found that Revlimid-resistant myeloma cells had significantly higher levels of CD44 compared to Revlimid-sensitive myeloma cells. CD44 is a protein that is involved in keeping cells attached to tissue; myeloma cells high in CD44 bind to bone marrow tissue, thereby resisting treatment with Revlimid. Another marker for Revlimid-resistance that has been recently discovered is cereblon; myeloma cells with low levels of cereblon do not respond to treatment with Revlimid (see related Beacon news). The M.D. Anderson researchers also found that the leukemia drug tretinoin (all-trans retinoic acid, Vesanoid) was able to reduce the amount of CD44 in myeloma cells and re-sensitized myeloma cells to Revlimid therapy in both human and mice samples. Based on the findings, the investigators believe that a combination of tretinoin and Revlimid may be effective in Revlimid-resistant patients. For more information, please refer to the study in the journal Leukemia (abstract).

Snake Venom Shows Anti-Myeloma Activity – Results from a recent preclinical study conducted in the Middle East show that venom from the desert black snake, also known as the desert cobra or desert python, may have anti-myeloma activity. The snake venom was administered by itself or inside of nanoparticles, which are extremely small objects that can deliver drugs to specific cells in the body. The researchers found that, in mice with multiple myeloma, the anti-myeloma effect of the snake venom was greater when delivered inside of nanoparticles. Previous preclinical studies have shown that snake venom also may be effective in treating solid tumors, such as breast, colon, and prostate cancer. For more information, please refer to the study in the journal Cellular Immunology (abstract).