May 20, 2025
Another Day Pharma announces successful Phase II trial results for BZ371A in post-prostatectomy erectile dysfunction
First-in-class therapeutic peptide BZ371A confirmed as effective and well-tolerated
Another Day Pharma Ltd, a company developing innovative therapies for sexual dysfunction in both men and women, today announced Phase II results for its new treatment BZ371A in post-prostatectomy erectile dysfunction. Trial results show that BZ371A in gel form can improve men's ability to have an erection that allows sexual intercourse following radical prostatectomy due to prostate cancer.
In the Phase II clinical trial in 74 men between 40 and 68 years, BZ371A met its primary endpoint of assisted erectile dysfunction (ED) either as monotherapy or in combination with tadalafil, the current standard of care. ED was assessed using the International Index of Erectile Function (IIEF) Questionnaire, domain A (erectile function section) (IIEF-EF) and success was defined as the percentage of men experiencing an increase of more than 4 points.
Key Results
Combination Therapy (BZ371A + Tadalafil)
Men who received combination therapy after surgery were 10 times more likely to respond after 30 days of treatment compared with tadalafil alone:
38%
Success rate with BZ371A + tadalafil
4%
Success rate with tadalafil alone
(p<0.05)
BZ371A Monotherapy
BZ371A monotherapy was also superior to tadalafil alone:
-
•
At 30 days: 15% success rate compared with 4% (tadalafil alone)
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•
At 60 days: 32% success rate compared with 13% (tadalafil alone)
Due to its localised topical application, BZ371A was shown to be well-tolerated with no serious adverse events and no adverse events that led to discontinuation of the medication.
Mechanism of Action
BZ371A is a synthetic non-hormonal peptide derived from the venom of the Phoneutria nigriventer spider, known for causing priapism - long-lasting painful erection - in bite victims. BZ371A can induce an erection even in the absence of sexual stimulation.
It stimulates production of nitric oxide (NO), triggering production of cyclic guanosine 3',5-monophosphate (cGMP) which provokes endothelial muscle relaxation and increased blood flow, leading to an erection.
This new and unique mechanism of action makes BZ371A particularly valuable for men whose neural pathways have been compromised, such as after prostatectomy. Although BZ371A has the potential to function independently, its mechanism of action is complementary to phosphodiesterase type 5 (PDE5) inhibitors such as tadalafil so the two treatments can be taken together, leading to a stronger erection.
Expert Commentary
"We are delighted that these trial results show that BZ371A is proving to be a well-tolerated, effective option for men undergoing radical prostatectomy, either as monotherapy or concomitantly with tadalafil. The results support the advancement of BZ371A into Phase III trials and reinforce its potential to address other forms of ED."
— Paulo Lacativa, Clinical Researcher at Biozeus Biopharmaceuticals
"BZ371A offers a new way of treating ED that we hope will benefit, in the future, the many men who don't respond to or are unable to take PDE5-inhibitors. We are now seeking strategic partnerships with pharmaceutical companies interesting in licensing or co-developing this product."
— Carlos Sanchez, Director at Another Day Pharma
Clinical Context
Around 60,000-70,000 men in Europe and 161,000 in the US undergo radical prostatectomy every year and more than 90% of them will have ED immediately after surgery. These men are at risk of irreversible erectile tissue damage without early intervention.
Surgical damage to the nerves and blood vessels can lead to long-term loss of erectile function and current treatment with the PDE5-inhibitor tadalafil daily for 18-24 months offer limited benefit since no treatment improves recovery of spontaneous erections. Patients are often left with few effective options to prevent progression of tissue damage and permanent loss of erectile capability.
References
- ClinicalTrials.gov: NCT05558007
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