The Viagra patent will no longer be renewed. What will replace it?

As was the case with Cialis a little earlier, the patent for Viagra will end in 2020. As the latest patents for the most famous drug for erectile dysfunction expire, interest in finding new treatments for this disease has resumed again.

Viagra patent ends this year

Are we witnessing the end of the era of Viagra and Pfizer? asks the British tabloid Guardian. Since the famous "little blue pill" exploded into the market in 1998, becoming the best-selling drug in history, the American pharmaceutical giant has made huge sums selling it to patients with erectile dysfunction around the world. Within three months of its launch, Viagra has already earned $400 million for Pfizer, and has generated $1.8 billion in annual sales over the past two decades.

This will soon come to an end, however, as Pfizer's remaining Viagra patents expire forever in 2020. Over the past six years, many generic versions have emerged, often in fancy forms such as mint chewable strips or breath sprays, as Pfizer's control over drug rights has gradually loosened. Generics are expected to flood the market soon as generics compete for their piece of the cash pie.

The patent for Viagra will end, so what? thinks the average consumer. Firstly, it promises to make the drug more accessible and cheaper, and secondly, for the millions of men around the world suffering from erectile dysfunction, it could also bring good tidings of much-needed innovation in treatment.

Since the launch of Viagra, few truly new therapies have been developed, and although Viagra and similar drugs such as Cialis and Levitra, which also increase blood flow to the penis by blocking an enzyme known as PDE5, are effective in about 70% of patients , all of them have significant drawbacks.

For starters, PDE5 inhibitor drugs like Viagra have side effects ranging from headaches and indigestion to vision problems.

Also, due to the fact that Viagra takes more than an hour for the active substance sildenafil to start working, users need to plan sexual intercourse in advance, and in the case of older patients, the drug can often be contraindicated due to its potentially dangerous interaction with drugs for high blood pressure. blood pressure or hypertension.

For men with the most severe forms of erectile dysfunction, often following nerve damage from diabetes or prostate cancer surgery, Viagra generally doesn't work at all.

We need a more effective medicine

The need for a more effective drug is especially urgent as erectile dysfunction becomes more common, and by the middle of this decade, its global prevalence will exceed 300 million. Scientists have long debated whether this is simply a consequence of men becoming more open about their sexual dysfunctions, or whether it is a side effect of other health problems. So far, one thing is clear: the market is growing.

"There is a huge need for new treatments for impotence that will work in as many patients as possible, yet have a longer acting effect to improve spontaneity and reduce the stress of having to take them on a regular basis," says Dr. Samit Soni , a urologist at Baylor College of Medicine in Houston. "Many patients would like to be able to take something and then not have to worry about it for 30 days."

But now there are few such options. The only alternatives to viagra:

None of them are completely acceptable.

Why is that? While some pharmaceutical companies have tried and failed to push competing drugs into clinical practice, Viagra's powerful profit-making mechanism has created a monopoly. At the same time, most companies shied away from developing this problem, perceiving it as too big a risk. But now experts believe that everything can change.

"Over the years since the development of Viagra, little has changed in our understanding of erectile dysfunction and how to treat it," Soni says. "But with the expiration of the patent, there has definitely been renewed interest in alternative treatments for erectile dysfunction and using them to develop new ideas that can be patented to generate sustainable profits for the industry."

Viagra 2.0 Eroxon?

Back in the early 2000s, specialists from the pharmaceutical company Futura Medical came across archival evidence of heart medications that apparently accidentally caused erections.

"There have been a few anecdotal reports of men deliberately spraying this product on their penises," says Ken James, head of R&D at Futura. "These sightings were reported in the scientific literature, and the company hoped they could make money from it."

The effects described were caused by a specific molecule known as glyceryl trinitrate or GTN, which causes the blood vessels in the penis to dilate, increasing blood flow. The main reason Futura was interested was that Viagra, Cialis and other similar drugs had to be taken orally. That is, they reach their goal through the bloodstream and thus interact with other systems in the body, including in a negative way.

GTN can be rapidly absorbed into the erectile tissues of the penis through the skin. This meant that it could be applied directly as a small amount of gel or cream with almost instant results and without any nasty side effects to blur the effect of Viagra.

"Viagra and Cialis are pretty effective drugs, but 50% of men stop using them within a year," says James. "60-70% of patients have some degree of dissatisfaction with them. This shows that there is an opportunity to solve many of these problems if we can enter the market with something new."

Over the past decade, Futura has developed a GTN-based gel called Eroxon, which appears to be able to induce an erection in patients with mild to moderate erectile dysfunction in five to ten minutes. Already dubbed the new Viagra, it appears to be the first truly new impotence treatment in twenty years, and Futura has even tentatively estimated a $1 billion potential commercial benefit from the drug.

Following renewed investor interest in supporting new treatments for ED, Futura completed a clinical trial of 232 patients last year and has now entered a final Phase III study of 1,000 patients, due to be completed by the end of 2019. If successful, Eroxon could become clinically available within the next few years, although urologists prefer to remain cautious for now.

"The biggest question in this Phase III trial will be whether Eroxon can match the clinical efficacy of Viagra," Sony says. "We have seen in the past that it is difficult to achieve the same efficacy when applied topically, but since then our understanding of how the drug can be absorbed through the skin into the bloodstream has improved significantly."

What to expect with complete impotence?

But even Futura scientists admit that Eroxon is unlikely to help in the most severe cases of erectile dysfunction, which affect about 20-30% of patients, usually due to nerve damage in the lower abdomen.

In the past, these men had few options other than penile prosthetics, but over the past five years there has been a renewed scientific interest in erectile dysfunction that has led research programs to devote more time and money to clinical trials of a technology known as shock wave therapy. Unlike Viagra or Eroxon, this treatment attempts to reverse the problems that cause dysfunction by sending low-intensity sound waves through the erectile tissue.

Desperation has driven many to private clinics that offer shock waves, stem cell infusions or plasma injections. Scientists are still not entirely sure how and why this works, but it is believed that these methods lead to the regeneration of erectile tissue, promoting the growth of new blood vessels and cleaning existing ones.

"Improved function of these vessels leads to improved blood flow and erection in these patients," explains Georgios Hatzichristodoulou, who is researching shock wave therapy at the University of Würzburg in Germany.

However, because there is a wide range of causes of erectile dysfunction, shock wave therapy is currently only known to work in some of these patients, mainly those whose damage is caused by diabetes or hypertension.

We will have to wait for more scientific evidence as a series of shock wave therapy trials are currently underway in Europe and the US. But compared to Viagra or Eroxon, a huge and main plus of such treatment is that it is not required on a regular basis. Instead, patients can simply receive maintenance therapy every six months or annually.

The hope of restoring the natural function of the penis and a possible cure may be realized in the coming years.

Searching for a super cure for impotence

Even when Viagra works, one problem for men who need to take it on a regular basis is that it becomes less effective over months or years.

"This happens quite often. Some patients may experience worse erections after being on Viagra for a while," says Hatzichristodoulou. "They take Viagra for five, six, 10 years, and on some days they feel that the erection does not improve."

Desperation has driven many patients to unscrupulous private clinics around the world that promise definitive cures by offering treatments such as shock waves, stem cell infusions and platelet-rich plasma injections on an unregulated basis. But all of these treatments are highly experimental, for example, shock wave therapy is currently only approved by the US Food and Drug Administration to promote wound healing, as scientists are still working to establish the best doses for effectiveness and study long-term safety.

"Of course, there is some very compelling evidence for shock wave therapy in some patients," Soni says. "But it's still at an early stage."

While scientists are hopeful that shockwave therapy may come to the fore within the next five to ten years, progress is also being made towards longer-term therapies such as gene therapy, which may offer a complete cure.< /p>

At Kaiser Permanente Research in northern California, a team of scientists has identified a genetic trigger believed to be unique to sexual function. They believe it plays a critical role in controlling the brain signals that initiate erections, and new genome-editing technologies such as Crispr-Cas9 may one day allow scientists to activate this trigger in patients.

"This genetic function is part of a process that controls the functioning of various body systems, from pigmentation to weight and sexual function," explains project leader Eric Jorgenson. "But what's amazing about this is that it seems to be very specific to the sexual system, which would allow it to be targeted and not disrupt anything else in the body. But that's still a long way off. We need to pinpoint the part brain where this trigger is active, and then test it in mice".

Because genome editing is still an experimental concept, Jorgenson thinks it will take time for scientists to make sure it's safe.

While gene therapy is only a distant prospect, on the horizon, for the first time in decades, new treatments for erectile dysfunction are clearly visible. With the end of the Viagra era approaching and research funding increasing, this area has been at its healthiest for many years.

"For many years there has been no real innovation in the treatment of erectile dysfunction," Soni says. "These new discoveries and treatments offer an uplift in a field of healthcare that has truly lulled me to sleep for a long time."