Petros Pharmaceuticals, Inc. (PTPI)

Petros Pharmaceuticals is a small pharmaceutical company focused on a single therapeutic area: oral treatments for erectile dysfunction. Its flagship product is Stendra (the generic name avanafil), a phosphodiesterase-5 inhibitor that was originally approved by the FDA in April 2012 for prescription use. The company’s ticker symbol on NASDAQ is PTPI.

Petros’ strategic focus has narrowed considerably over its life. Originally it held multiple programs and competed in a crowded field. Today, the company’s main bet is on transforming Stendra from a prescription drug into the first PDE-5 inhibitor available over the counter—a transition that would reshape how the drug is marketed, distributed, and priced.

The merger that created Petros

Petros Pharmaceuticals was incorporated in May 2020 through a merger that brought together three entities: Neurotrope, Inc., Metuchen Pharmaceuticals LLC, and related subsidiaries. The merger was designed to consolidate control of Stendra and to give the combined entity funding to develop and commercialize it.

Metuchen Pharmaceuticals had relaunched Stendra in 2019 after the drug had lost market prominence. At the time of the 2020 merger, the recapitalization and relaunch generated approximately 20 million dollars in funding for the newly formed Petros.

The company went public in December 2020 through an initial public offering at $5.00 per share, raising roughly 11 million dollars. A small IPO like that provides working capital for a small-cap biotech, but it also meant the company started life with limited resources relative to its ambitions.

Stendra and the PDE-5 market

Avanafil was originally developed and approved as Stendra by Auxilium Pharmaceuticals. When Auxilium was sold to Endo Pharmaceuticals, control of Stendra moved with it. Stendra competed in a market already dominated by older, more established PDE-5 inhibitors: sildenafil (Viagra), tadalafil (Cialis), and vardenafil (Levitra). By the time Petros acquired it, Stendra held only a small share of the roughly four-billion-dollar erectile dysfunction treatment market—somewhere in the three-percent range.

The appeal of avanafil was a faster onset of action compared to some competitors: it could work in 15 to 30 minutes, whereas other PDE-5 inhibitors might take 30 to 60 minutes. But faster onset alone was not enough to overcome the dominance of established brands and generic competitors. Petros faced a choice: compete on efficacy and convenience in a saturated market, or pursue a different strategy.

The shift toward over-the-counter approval

Beginning in 2021, Petros began pursuing a novel regulatory pathway: seeking FDA approval to switch Stendra from prescription to over-the-counter status. If approved, Stendra would be the first drug in the PDE-5 inhibitor class available without a prescription—a significant competitive advantage.

The challenge is real. PDE-5 inhibitors can interact dangerously with nitrate drugs (used for angina and other cardiac conditions). A patient on nitrates who takes a PDE-5 inhibitor risks a potentially life-threatening drop in blood pressure. In prescription settings, physicians screen for contraindications. Over the counter, the company must rely on patients to screen themselves using written instructions and, potentially, a smartphone app or other technology to verify they are not on incompatible medications.

In 2022, the FDA approved expanded labeling for Stendra to include clinical trial data showing efficacy in men with erectile dysfunction who had undergone radical prostatectomy—a narrow but meaningful expansion of the label’s claims.

Recent FDA engagement and the OTC pathway

The real momentum shifted in 2023 and 2024 as Petros demonstrated its approach to FDA reviewers. In April 2024, the company announced positive feedback from the FDA following a demonstration of a technology component designed to help patients self-screen for contraindications. The FDA acknowledged that the technology addressed some of the agency’s concerns about safety in the over-the-counter setting, particularly regarding nitrate interactions.

Petros also reported successful results from an initial app comprehension test—evidence that patients could understand and follow instructions delivered through digital means. This became critical to the company’s case: if patients could reliably use a smartphone app or web tool to verify they were not on nitrates, the FDA might be willing to approve OTC status.

As of early 2024, Petros had scheduled two meetings with the FDA to discuss the path forward for the OTC switch.

Current operations and risks

By 2024, Petros had exited the vacuum erection device business that it once held alongside Stendra. The company assigned certain subsidiaries’ assets for the benefit of creditors—a restructuring that narrowed the business to its core: pursuing the OTC switch for Stendra.

This strategy carries execution risk. The FDA has never approved a PDE-5 inhibitor over the counter, and regulatory approval is not guaranteed. If the FDA declines to approve the switch or demands modifications that make the app or screening process unworkable, the company would face a very limited commercial path forward.

The company operates with limited cash and no near-term revenue outside of whatever lingering prescription Stendra sales remain. The entire business case depends on the OTC switch succeeding within a reasonable timeframe.

Researching Petros as an investor

The 10-K filing (SEC CIK 0001815903) contains details on remaining cash balances, burn rate, and the terms of any partnerships or agreements with potential commercialization partners. FDA meeting summaries, when published, provide clarity on the regulator’s concerns and the likelihood of approval. News releases about app testing, patient comprehension studies, and FDA feedback directly indicate progress toward the OTC switch. Anyone studying Petros should understand that the company’s survival and value depend almost entirely on this single regulatory outcome.