Clinuvel Pharmaceuticals (ASX: CUV) has been given the all-clear to market its afamelanotide drug (brand-named Scenesse) by the US Food and Drug Administration (FDA).
The drug was already approved by the European Medicines Agency in 2014 and constitutes the company’s lead compound that combats phototoxicity.
The regulatory path to approval has taken over a decade, starting with clinical trials in erythropoietic protoporphyria (EPP) patients in Europe in 2006. The FDA then granted the compound with an orphan drug designation in 2008, recognising the rarity, severity and unmet need in EPP – a condition that affects around 5,000 to 10,000 people worldwide.
A phase 2 US clinical trial then commenced in 2010, followed by a phase 3 US clinical trial in 2013, with results subsequently published in the New England Journal of Medicine. The FDA then awarded Scenesse with “fast track status” in May 2017 and conducted a priority review in January 2019.
Furthermore, under the US Orphan Drug Act of 1983, the FDA granted the drug with seven years of market exclusivity from competitors.
A ray of hope for EPP sufferers
Scenesse is thereby a new drug and represents the world’s first-ever treatment for a rare genetic metabolic disorder, which causes absolute intolerance to light, otherwise known as EPP.
The “erythropoietic” in the name refers to an association between red blood cells (erythron) and the process the facilitates their formation (poietic).
The porphyrias are a group of uncommon diseases caused by problematic production of chemicals known as porphyrins. These chemicals are the building blocks of haem, which, when combined with a protein (globin), forms haemoglobin, the material in red blood cells that carries oxygen around the body.
In the case of EPP, there is a build-up of one of these porphyrins (protoporphyrin) in the blood, especially in the red blood cells – which leads to an inability to tolerate sunlight.
Even in its mild form, EPP patients must avoid all sources of light exposure throughout their life, or risk developing “incapacitating burns”.
The condition is considered to be hereditary with no known cure. However, sufferers are typically given a range of mitigatory treatments that can alleviate symptoms.
Existing EPP sufferers report they experience “excruciating burning pain” underneath their skin which can last days or weeks and forces them to avoid all further exposure to light.
According to Clinuvel, the drug works by “binding to the melanocortin-1 receptor on skin cells” which sets into motion a “cascade of cellular events”, one of which is the activation of the pigment melanin to provide a physical barrier to visible and invisible light in EPP patients.
The drug is administered as a 16mg controlled-release injectable implant that provides protection for up to 60 days.
With FDA approval received, Clinuvel declared that its Scenesse drug can “increase pain-free light exposure in adult patients with a history of phototoxic reactions from EPP”.
“Today is a memorable day and victory for EPP patients, their families, and the global medical community who have all supported the development and US approval of the first-ever treatment for this debilitating condition and the world’s first systemic photoprotective drug,” Clinuvel chief scientific officer Dr Dennis Wright said.
“Scenesse is a novel drug that provides photoprotection for EPP patients, enabling patients to be exposed to light and providing them a freedom they never had,” he added.
News of FDA approval this morning sent Clinuvel shares up by almost 36% up to $38.14 per share.