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Nippon Chemiphar Presents Promising Data on Novel Prescription Cough Medicine, Representing Possibly Second New Rx Cough Drug to Enter Market Since 1950s

Washington, D.C./Tokyo Japan, July 17, 2021 — Japanese pharmaceutical manufacture Nippon Chemiphar Co., LTD is developing a novel, first-in-its-class prescription cough medicine that has the potential to become the second new Rx cough product in roughly 70 years.

The company completed a successful phase 1 trial of its compound NC-2600, a P2X4 receptor inhibitor for treating nonproductive chronic cough.

Health care providers and patients have not had a new Rx cough treatment since the 1950s, and data shows a significant unmet need exists for new products. Analysis of patients with chronic cough has found that the most common unmet need was the lack of effectiveness of treatment (49.3%), followed by unclear diagnosis (30.1%), medical costs (6.2%), and adverse effects of treatment.

Nippon Chemiphar’s NC-2600, an oral once-daily formulation for treating nonproductive cough, has the potential to fill this need. The company presented positive findings of its clinical trials on NC-2600 at the June 2021 BIO International Convention.

“The market lacks an effective cough medicine for this group of patients,” says Dr. Koki Hayamizu, VMD, head of development planning at Nippon Chemiphar. “Now is the time to bring a new and much needed chronic cough medicine for pulmonologists, primary care/internal medicine doctors and other providers to prescribe to U.S. patients and around the world.”

Market trends analysts predict that developments in the pharmaceutical industry for drugs treating chronic cough are likely to lead the market growth. The oral segment (over injection, inhalation, and other routes of administration) holds the largest share of the market.

Why NC-2600 Is Unique

Dr. Hayamizu presented data on NC-2600 at BIO 2021.

NC-2600 is an oral formulation with expected once-daily administration of 5 to 10 mg. NC-2600 is the only P2X4 receptor antagonist for chronic cough in clinical development. This first-in-class peripheral antitussive agent is expected to suppress excitation of afferent Aδ fibers that send signals to the cough center in the brain by inhibiting the P2X4 receptor on the respiratory tract.

P2X4 receptor inhibition is reported to:

  • Suppresses cough sensitivities increased by airway inflammation.

  • Prevents airway contractions and suppresses cough sensitivities in the tracheal smooth muscle.

  • Suppresses degranulation of mast cells and histamine release, which induces cough.

This mechanism is different from the many over-the-counter (OTC) antitussive medications on the market, which cough experts say are ineffective. And unlike the narcotic-containing prescription cough suppressants, which are no longer recommended for children or adults due to the opioid crisis, it contains no narcotic, and so will not require a black box warning for overdose, that is required for both narcotic and non-narcotic cough suppressants currently on the market. (Benzonatate, for instance, is a prescription non-opioid alternative for the symptomatic relief of cough that acts as an anesthetic and if absorbed by the oral mucosa can cause life-threatening adverse effects.)

NC-2600 also differs from its potential competitors, such as the P2X3 receptor antagonists that have been developed for chronic cough in clinical studies. These emerging agents have been associated with undesirable side effects, such as taste disorders. The P2X4 receptors, by contrast, are not expressed on taste buds and no such events were observed in NC-2600 phase 1 studies.

How they work: The P2X3 receptor antagonist usually inhibits cough stimulus transmission through C fiber, whereas the P2X4 receptor antagonist is supposed to inhibit cough stimulus transmission through not just C fiber, but also Aδ fiber. Based on this, the company believes targeting P2X4 to be effective for wider range chronic cough than the P2X3 receptor antagonist.

Furthermore, animal studies on NC-2600 confirmed efficacy in several guinea pig models. NC-2600 significantly reduced cough numbers in citric acid-induced cough model, OVA sensitized model and C-fiber desensitized model. NC-2600 showed antitussive effects dose dependently and NC-2600 at 10mg/kg po decreased number of cough reflexes in allergic cough model.

Indicated for Nonproductive Cough

Expectorants, such as OTC guaifenesin (Mucinex), which reduce mucous, are not recommended for nonproductive chronic cough. By contrast, NC-2600 is expected to be indicated for nonproductive cough, which does not increase airway mucus, and to be used for a wider range of cough patients.

“A pharmaceutical company that bring this chronic cough treatment to market will have the opportunity to greatly improve the lives of patients,” says Dr. Hayamizu.

Gout Medications Also In Development

In addition to cough treatments, Nippon Chemiphar also is developing new medications for gout, which is expected to grow in prevalence worldwide. The company’s two compounds, NC-2500 and NC-2700, for treating hyperuricemia associated with gout have the potential to provide safer, more effective alternatives for the growing number of patients with gout. Nippon Chemiphar would like to out-license both gout treatments to a pharmaceutical manufacture.

About Nippon Chemiphar

Nippon Chemiphar is a Japanese pharmaceutical company founded in 1950 and is engaged in ethical pharmaceuticals, diagnostics and healthcare-related products.  Its annual sales in FY2020 was 32 billion JPY.  The company has been focusing on research and development of innovative small molecule medicines and seeks out-licensing or collaboration for late-stage clinical development usually after Phase-1.


Peter Sonnenreich

President & CEO

Kikaku America International

Direct 202-246-2525


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