Oncolytic adenoviruses are promising immunotherapeutic agents for the treatment of cancer. .Considering the role of the host immune system, treatment-naive patients with early stage localized prostate cancer were enrolled in a phase I trial with ORCA-010. ORCA-010 is a potency enhanced oncolytic replication competent adenovirus, developed to be specifically infect and kill cancer cells. 

Treatment-naïve prostate cancer patients with localized disease were treated with a single intratumoral administration of ORCA-010. Nine patients in three dose escalation cohorts (1x1011, 1x1012 or 1.5x1012 viral particles/administration) were treated based on a 3+3 design with a 1-year follow-up period.The primary study objectives include the safety profile and tolerability of intratumoral administration . Secondary objectives include 1) evaluation of the biological activity and antitumor efficacy of intratumoral administration ; 2) to evaluate potential antitumor responses and 3) to assess shedding of ORCA-010.

Nine patients with localized prostate cancer have been treated with a single intratumoral administration of ORCA-010.  Treatment related adverse events were limited to transient grade I and grade II adverse events.Shedding analyses demonstrated active replication of ORCA-010 post administration and a viremia peak was observed in all patients within 1 week post administration. PSA levels increased significantly post administration, coinciding with ORCA-010 DNA levels, and returned to pre-administration levels at 1-3 months. Preliminary analyses of the MRI data in patients demonstrated a significant reduction of prostate size 6 months post treatment and reduced tumor load.

Intratumoral administration of ORCA-010 in treatment-naïve prostate cancer patients demonstrated an excellent safety profile. Preliminary analyses demonstrate viral replication post administration, encouraging anti-tumor activity and prostate size reduction in prostate cancer patients with enlarged prostates.