Intraprostatic PRX302 Injection to Treat Localised Prostate Cancer

A multi-centre, open label, phase IIb study, evaluating the safety, tolerability and efficacy
of a targeted intraprostatic focal administration in development. The study will treat
approximately 40 men who meet the eligibility criteria, and give written consent. Safety and
tolerability will be assessed post-treatment over 26 weeks. Efficacy will be assessed by
biopsy and imaging (mpMRI) at 24 weeks.

Inclusion Criteria:

- Life expectancy ≥ 10 years.

- Serum prostate-specific antigen (PSA) ≤ 15ng/mL.

- A histologically proven, clinically significant lesion visible on mpMRI (magnetic
resonance imaging) that is accessible to PRX302 transperineal injection.

- Radiological stage T1-T2 N0 Mx/M0 disease.

- Targeted prostate biopsy within 6 months prior to dosing, with a clinically
significant lesion correlating with an mpMRI visible lesion.

Exclusion Criteria:

- Previous radiation therapy to the pelvis.

- Androgen suppression or anti-androgen therapy within the 12 months prior to dosing,
for prostate cancer.

- Use of 5-alpha reductase inhibitor within the 3 months prior to dosing.

- Evidence of metastatic disease or nodal disease outside the prostate on bone scan or
cross-sectional imaging.

- Inability to tolerate transrectal ultrasound (TRUS).

- Known allergy to latex or gadolinium (Gd).

- Prior rectal surgery preventing insertion of the TRUS probe.

- Any previous ablative procedures performed on the prostate, e.g., electroporation,
radiofrequency ablation, high-intensity focused ultrasound (HIFU), cryosurgery,
photochemical, thermal or microwave therapy to treat cancer of the prostate.

- Unable to have pelvic MRI scanning (severe claustrophobia, permanent cardiac
pacemaker, metallic implant, etc., likely to contribute significant artifact to
images).