Inclusion criteria:

1. Males aged ≥45 years, weighing ≤200 Kg and able to provide written, informed consent.
2. Documented symptoms of BPH-LUTS for 6 months or more.
3. For patients regularly taking their prescribed medication, dose should have been stable for at least 6 months for 5-alpha reductase inhibitors and 3 months for others.
4. For patients who have withdrawn from regularly taking their prescribed medication, there should have been a 6 month washout period for 5-alpha reductase inhibitors and 3 months for others.
5. Have a total International Prostate Symptom Score (IPSS; Qs 1-7) of 15 -30 (inclusive).
6. Prostate volume of 30 - 80 mL (inclusive).
7. Maximum urinary flow rate (Qmax): 5 - 15 mL/sec (assessed on two voids of ≥ 150mL).
8. Prostate-specific antigen (PSA) ≤10 ng/mL.
9. Post-void residual (PVR) volume ≤200 mL.
10. Prostatic urethral length (PUL) of between 30 - 55mm (inclusive).
11. Willing and able to comply with photosensitivity precautions

Exclusion criteria

1. Any history of minimally invasive or surgical treatment for BPH or any other prostatic condition.
2. Subjects weighing >200 Kg.
3. Subjects with a history or current evidence of any of the following:
   1. Active urinary tract infection i.e. must have a screening urinalysis without signs of infection or negative urine culture. Must not have had a previous symptomatic urinary tract infection within 4 weeks of the study.
   2. Urethral stricture or any other anatomical feature that would complicate catheterisation.
   3. Interstitial cystitis.
   4. Predominant middle lobe obstruction, as indicated by a degree of intra-vesical prostatic protrusion (IPP) on TRUS of >10mm.
   5. Prostate or bladder cancer or bladder carcinoma-in-situ - in particular, evidence from digital rectal exam (DRE) of prostate abnormalities suggestive of cancer in the last 12 months.
   6. Any other absolute indication for urosurgical intervention (such as acute or frequent retention, stones, untreated bladder stones, urethral strictures/bladder neck contracture (BNC)).
4. PSA level in excess of >10 ng/ml. If the PSA measurement is 2.5-10 ng/ml and/or has shown a clinically significant concerning increase in the last 6 months, local standard of care must be pursued to ensure the possibility of prostate cancer has been followed up and ruled out prior to study entry.
5. Subjects who had had a prostate biopsy within 6 weeks prior to Screening.
6. Any neurological condition affecting the bladder or a history of a neurogenic or chronically decompensated bladder i.e. neurogenic bladder, Parkinson's disease, history of chronic prostatitis within the last 5 years.
7. Prior treatment for urinary incontinence.
8. Requirements for daily incontinence pads or devices.
9. Subjects in whom nocturia is a predominant feature of their LUTS, including:
   1. Those in whom estimated >33% of their 24h urine output is voided at night.
   2. Those with an alternative potential cause for nocturia, such as congestive heart failure, hepatic failure, nephritic syndrome, sleep disorder.
10. Subjects in whom the possibility of a concurrent over-active bladder exists, as indicated by:
    1. A score of 4 points or greater on the 3-item OAB Awareness Tool (OABV3), or
    2. High rates of urinary frequency (>13x/day and/or >4x/night).
11. Previous or concurrent clinically relevant cardiovascular or cerebrovascular disorder within 24 weeks prior to the study i.e. unstable angina pectoris, myocardial infarction, transient ischemic attack, or cerebrovascular accident (stroke) within the past 6 months, or peripheral arterial disease with intermittent claudication or Leriche's syndrome.
12. Presence of serious hepatic diseases, renal diseases, immunological diseases, or pulmonary diseases that are clinically relevant.
13. Unwilling to use contraception for 3 months following administration of study medication or with an interest in future fertility.
14. A prolonged QTcF interval at baseline and/or who are currently taking medication that prolongs QT interval ("prolonged QTcF interval" defined as > 450 ms).
15. Known sensitivity to porphyrin-type drugs or known history of porphyria.
16. Any contraindications to use of the study treatment.
17. Active alcohol or drug abuse.
18. Subject has clinical laboratory test results outside the reference ranges of the testing laboratory that are deemed to be clinically significant. Subjects with isolated test results that are outside the specified ranges and that are assessed as clinically insignificant will be allowed at the discretion of the Investigator, after discussion with the Sponsor's Medical Monitor/Study Physician, if appropriate. If a subject has 1 isolated test result outside the specific range that is deemed potentially clinically significant, rescreening may be allowed at the discretion of the Investigator, after discussion with the Medical Monitor/Study Physician
19. Subjects with known disorders of coagulation, apart from those receiving anticoagulant / antithrombotic / antiplatelet therapy in whom the dose of such medication must have been stable for at least 1 month prior to randomisation. In those receiving Vitamin K antagonists (warfarin, acenocoumarol, phenindione, etc) the INR value at Screening should be <3.0.
20. Inability or unwillingness to comply with the required photosensitivity precautions during the three weeks following study treatment.
21. Subjects taking medications with a recognised propensity for causing photosensitivity (such as amiodarone, tetracyclines, sulphonamides) that cannot be discontinued for the initial study period, namely from 14 days prior to administration of study medication until 28 days afterwards.
22. Subjects with medical or investigation results deemed unfit for study treatment, as determined by medical history, clinical laboratory tests, ECG results, and physical examination that, in the Investigator's opinion, preclude entry into the study.
23. Subjects who have received an investigational medicinal product within 30 days or 5 half-lives of the investigational product prior to study entry (defined as the start of the Screening Period).
24. Subjects who are incapable of giving informed consent or complying with the protocol.