By :- Subhi Sharma
A New Drug Application (NDA) has been submitted to the U.S. Food and Drug Administration (FDA) seeking approval of Avanafil, its investigational drug for the treatment of erectile dysfunction (ED). The NDA submission follows the successful completion of an extensive phase 3 program for Avanafil, which included over 1,350 patients, where Avanafil was shown to be well tolerated and effective in treating men with ED.
This NDA filing is yet another major milestone for VIVUS and the Avanafil program. The efficacy was uniform across all patient groups, with success observed in some patients in as early as 15 minutes after dosing. The drug was well tolerated and had a low dropout rate in all of the clinical trials. If approved, avanafil could be an attractive treatment alternative for those who suffer from ED. The unique profile of potentially faster onset and greater selectivity should allow avanafil to effectively compete in the $4 billion worldwide ED market.
The NDA includes results from two placebo-controlled, randomized, double-blind, multicenter studies: REVIVE, which included 646 men from the general population with ED, and REVIVE-Diabetes, which included 390 diabetics. Previously reported highlights from the Avanafil development program include:
- All doses tested 50 mg, 100 mg, and 200 mg met each of the co-primary efficacy endpoints of the studies
- Successful intercourse (SEP3) was achieved in 57% and 40% of avanafil patients at the 200 mg dose, as compared to 27% and 20% of placebo patients in the REVIVE and REVIVE-Diabetes studies, respectively
- Across all the phase 3 studies, successful intercourse (SEP3) was observed in some avanafil-treated patients as early as 15 minutes after dosing
- Significant improvement in erectile function as measured by IIEF-EF domain score was observed for all doses in avanafil-treated patients
- Erections sufficient for penetration (SEP2) were observed in 77% and 63% of avanafil patients at the 200 mg dose, as compared to 54% and 42% of placebo patients in the REVIVE and REVIVE-Diabetes studies, respectively
Sidenafil is an another orally active drug for treatment of Erectile Dysfunction (ED) It became an instant hit,but the enthusiasm has passed off now. It is recommended in dose of 50 mg but Sildenafil is is ineffective in men who have lost libido or when ED is due to cord injury or damaged nervi eregantis.
Brief about Erectile Dysfunction(ED)
Erectile dysfunction:- Impotence resulting from a man’s inability to have or maintain an erection of his penis. It is sexual dysfunction characterized by the inability to develop or maintain an erection of the penis during sexual performance.
Penile erection is managed by two different mechanisms. The first one is the reflex erection, which is achieved by directly touching the penile shaft. The second is the psychogenic erection, which is achieved by erotic or emotional stimuli. The former uses the peripheral nerves and the lower parts of the spinal cord, whereas the latter uses the limbic system of the brain. In both conditions, an intact neural system is required for a successful and complete erection. Stimulation of penile shaft by the nervous system leads to the secretion of nitric oxide (NO), which causes the relaxation of smooth muscles of corpora cavernosa (the main erectile tissue of penis), and subsequently penile erection. Additionally, adequate levels of testosterone (produced by the testes) and an intact pituitary gland are required for the development of a healthy erectile system. As can be understood from the mechanisms of a normal erection, impotence may develop due to hormonal deficiency, disorders of the neural system, lack of adequate penile blood supply or psychological problems. Restriction of blood flow can arise from impaired endothelial function due to the usual causes associated with coronary artery disease, but can also be caused by prolonged exposure to bright light.
More about ED will be explored in our next coming posts.