Topsalysin Aiding Majority of Prostate Cancer Patients, Early Clinical Trial Results Show

Topsalysin Aiding Majority of Prostate Cancer Patients, Early Clinical Trial Results Show
Sophiris Bio Inc., recently released six-month biopsy data from the first seven prostate cancer patients treated with its drug candidate PRX302 (topsalysin) in a Phase 2a proof-of-concept clinical trial. PRX302 is being developed for the treatment of lower urinary tract symptoms of benign prostatic hyperplasia (BPH) and of localized low- to intermediate-risk prostate cancer. PRX302 (topsalysin) is a modified recombinant protein engineered to be selectively activated by an enzyme in the prostate, leading to localized cell death and tissue disruption without damaging neighboring tissue and nerves. PRX302 binds to the GPI-anchored receptors on the surface of prostate cells. Once activated by PSA, a protein produced by normal and cancerous prostate cells, PRX302 combines with other activated PRX302 molecules to form stable transmembrane pores that induce cell death. Prostate-specific activation of PRX302 by enzymatically active PSA thus limits exposure of non-prostate tissues to the drug’s activity, the company reports, contributing to the therapy's safety. Biopsy data revealed that four of the seven patients who underwent treatment responded: one man had complete tumor ablation, and three others saw a decrease in the highest cancer core extent or a decrease in Gleason score. The remaining three had no response. "This new trial is very exciting — we have promising data showing that topsalysin can ablate cancer cells and we look forward to reviewing the results from the remaining 11 patients as they complete the study. We could be on the cusp of a new class of therapeutics for the focal treatment of
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Inês Martins holds a BSc in Cell and Molecular Biology from Universidade Nova de Lisboa and is currently finishing her PhD in Biomedical Sciences at Universidade de Lisboa. Her work has been focused on blood vessels and their role in both hematopoiesis and cancer development.


  1. Sharon Steiner says:

    My husband is in stage 4 with cancer migration to his breast and spine bones due to a biopsy. Is it too late for the drug described here?

    • Tim Bossie says:

      We are very sorry to hear about your husband and the migration of the cancer. To answer your question, we do not know for certain and can not give any type of medical advice concerning that. However, we would encourage you to contact your doctor with this information to see what they say.

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