It might be too much to use the word “cure” but there are several ways to help deal with it.
To start off, leaky penile veins is not really the problem. The problem is the patient cannot get a good and proper erection.
Is there a cure for leaky penile veins?
So the first obvious way to deal with the problem is to use treatments that can help the patient get a good erection. Basically you are improving the inflow to a point where it overcomes the higher than normal outflow due to the leaky veins. So usual treatments like PDE5Is and ESWT for ED can help. These treatments are good because they are relatively inexpensive and non-invasive.
To fix the leaky veins themselves, there are several methods:
Basically go in there and stitch up as many veins as you dare. Even in the hands of the best surgeons, this has a 60%+ success rate only. And the cure is not permanent. The body eventually will find and open up other tributaries for the blood to flow.
Basically cut open the penis, find the vein, stick a plastic tube in it, via this tube shoot a chemical into the vein that blocks it up. Again success rates are about 60%+ and not permanent.
3. Coil insertion
Basically stick a needle into the vein, thread a wire up to the point you want to block then stick a metal coil in there. Success rates are 60% to 70% and the coils can migrate over time.