Skin conditions like atopic dermatitis (eczema) and psoriasis are often chronic and hard to treat. They can have a meaningful impact on quality of life for those suffering from the maladies that result in itchy, scaly skin. Globally, some 125 million people are affected by psoriasis. After decades of relatively unsuccessful treatment options, biologics came along to save the day with better efficacy. In the process, they’ve made billions of dollars for big pharma, with the likes of Humira by AbbVie (NYSE:ABBV), Remicade and Stelara by Johnson & Johnson (NYSE:JNJ) and Enbrel by Amgen (NYSE:AMGN) cumulatively generating about $28.5 billion in sales last year alone. While all those drugs are indicated for psoriasis, they also treat other diseases and conditions, such as forms of arthritis and Crohn’s.
In November, Amgen won FDA approval of Enbrel, a tumor necrosis factor blocker, to become the first biologic for pediatric psoriasis.
These drugs could soon face competition, with biosimilar drugs (the equivalent of a generic for biologics) ready to come online, such as Novartis’s (NYSE:NVS) GP2015 as a copy of Enbrel and Amgen’s Amjevita, which became the fourth biosimilar approved by the FDA in September when it was green-lighted as equivalent to Humira. Amgen and AbbVie have both filed lawsuits trying to block the competitors from making it to market. Also joining in the fray are next-gen biologics Cosentyx by Novartis and Taltz from Eli Lilly (NYSE:LLY).
By approving biosimilars, the FDA hopes to help reduce healthcare spending by allowing for lower-cost alternatives to high-price branded biologics, much in the same way that generic drugs have help reduce pill prices. Expense and documented side effects are tradeoffs for some people to treat their condition. They also must endure regular shots, as all these biologics are administered through injections.
These factors underscore the value of oral pills to treat dermatologic conditions. They are also the reason that Celgene (NASDAQ:CELG) is gaining steam with Otezla, an oral phosphodiesterase 4 (PDE4) inhibitor approved for plaque psoriasis and psoriatic arthritis. Today, Celgene announced Otezla’s approval in Japan, marking the 37th country the drug is approved for marketing.
Only approved a little over two years ago, sales of Otezla clocked $275 million during the third quarter, putting it in the conversation for future “blockbuster” status by generating over $1 billion in sales over a 12-month period. Evaluatepharma estimates Otezla could generate $2.9 billion in annual sales in the next five years. In October, Celgene scored a victory with U.K. cost watchdog NICE changed its mind on Otezla and recommended it as an improvement in patient choice and “cost effective use of NHS resources.” In its guidance, NICE noted that Otezla doesn’t have the same efficacy as biologics, but may be a welcome alternative to injectables where patients are willing to sacrifice some effectiveness to have an oral medication.
The rapid market acceptance of Otezla and the recent comments by NICE speak to the value of a pill for psoriasis. The notion isn’t lost on Novartis, who recently put more skin in the game by acquiring U.K.-based Ziarco Group. The acquisition price was confidential, but analysts speculate the deal to be valued up to $1 billion when considering future milestone payments. The prize of the buyout is Ziarco’s lead product ZPL-389, an orally active H4 receptor antagonist that has completed a Phase 2a trial for eczema and is in early-stage research for psoriasis.
Also noteworthy in the space is Cellceutix (OTCQB:CTIX), which is bringing its experimental oral psoriasis drug Prurisol through mid-stage clinical trials. Earlier this year, the company successfully completed a 115-patient Phase 2a study of the immune modulating drug in patients with mild-to-moderate plaque psoriasis. Noticeable effect in skin condition, as measured by IGA score, was reported in as little as two weeks, with a progressive decrease in IGA score throughout 12 weeks of treatment. The trial met its primary endpoint with a 2-point reduction in IGA score in 35 percent of patients treated with 200 mg of Prurisol daily.
Cellceutix has initiated a Phase 2b trial of Prurisol, leveraging the safety pharmacokinetic profile of Prurisol to up the dosing levels to 300 mg and 400 mg in the intent to treat cohorts. A third cohort will receive placebo. After addressing mild to moderate patients (which are arguably harder to measure efficacy) in the Phase 2a study, the company is shifting to moderate to severe psoriasis patients for the new trial, in line with the sea of biologic therapies. Efficacy will be measured by PASI score (PASI 75 to be more precise), also on par with trials used for approved drugs.
Cellceutix believes that the higher dosing regimens of Prurisol have the potential to deliver results that rival biologics without the side effect threats, which would be an impressive feat if they can pull it off. Biologics that act through inhibiting glycoproteins known as interleukins – Taltz and Cosentyx target IL-17, for example – have demonstrated compelling response rates. While it acts through immune modulation and PRINS reduction, Prurisol also inhibits IL-20, which is known to have a key role in the pathogenesis and maintenance of psoriasis.
On Monday, Cellceutix said that patients in the 189-patient Phase 2b study are already being treated with Prurisol and that 24 of the 25 U.S. clinical sites are open for screening patients. The 25th site is expected to be open by the weekend.
Patients being dosed and the sites all open bodes well for the trial maintaining a quick pace, as the first Phase 2 study did. Cellceutix is expecting an interim analysis during the upcoming March-June quarter and complete top-line results in the next 6-9 months. If data is consistent with earlier research suggesting a greater therapeutic benefit via a higher dose in patients with more severe psoriasis, it could be a watershed milestone for the company, given that Cellceutix has mentioned being in conversations with big pharma. It’s likely that the addition of Dr. Arthur Bertolino, who held executive positions in dermatology divisions of Pfizer (NYSE:PFE) and Novartis, as Cellceutix’s President and CMO is instrumental in these discussions.