JERSEY CITY, N.J., March 3, 2014 /PRNewswire/ — S1 Biopharma today announced its plan to initiate Phase 2a clinical trials in the third quarter of this year for Orexa (S1P-205), its first-in-class therapy to treat male Hypoactive Sexual Desire Disorder (HSDD). The double-blind placebo-controlled study will be the first to evaluate a drug for male HSDD.

Key points:

  • Hypoactive sexual desire disorder is a sexual dysfunction disorder characterized by a lack or absence of sexual fantasies and desire for sexual activity, as judged by a clinician.
  • For this to be regarded as a disorder, it must cause marked distress or interpersonal difficulties and not be better accounted for by another mental disorder.
  • An estimated 16 million men in the U.S. and Western Europe have low sexual desire which may be HSDD.
  • There are currently no FDA-approved treatments for male or female HSDD.
  • Orexa (S1P-205) is the first and only drug in clinical development for HSDD in men.
  • S1 Biopharma plans to initiate enrollment in the double-blind placebo-controlled study in the third quarter of this year.
  • Orexa is similar to S1 Biopharma’s first-in-class therapy for female HSDD, Lorexys.
  • The development of Orexa benefits from the continuing success of S1’s Lorexys program.


Nick Sitchon, chief executive officer, S1 Biopharma said, “While efforts to develop drugs for erectile dysfunction have been very successful, there are no FDA-approved treatments for desire problems in either women or men. We are pleased to implement specific recommendations from the FDA regarding the Phase 2a clinical trial of Orexa for male HSDD which will be run in parallel with the Phase 2b trial of our first-in-class agent for female HSDD, Lorexys. We look forward to announcing the results of our Phase 2a trial of Lorexys in the second quarter of this year.”

About Hypoactive Sexual Desire Disorder (HSDD)

ICD-9/ICD-10 defines HSDD as a persistent or recurrent lack of desire for sexual activity. In the DSM-5, female sexual arousal and desire disorders are combined into female sexual interest/arousal disorder. In the DSM-5, male HSDD is defined as persistently or recurrently deficient or absent sexual/erotic thoughts or fantasies and desire for sexual activity. The DSM-IV and DSM-5 diagnostic categories also require that a patient experience significant distress resulting from the loss of desire. There are currently no FDA-approved drugs for these conditions, although there is a large unmet medical need. In a U.S. study of 30,000 women, it was found that 10% met these criteria for HSDD without depression or other possible causes. Several large studies estimate the prevalence in men at 3% to 15%.

About Lorexys

Lorexys is being investigated as a first-in-class drug for HSDD in women. It is designed to restore the balance of three neurotransmitters, dopamine, serotonin and norepinephrine, known to regulate sexual inhibition and sexual excitation. An oral, non-hormonal fixed-dose combination of two antidepressants, bupropion and trazodone, Lorexys is precisely balanced to neutralize the side effects of its individual components.

About Orexa

Orexa, while similar to Lorexys, is specifically formulated for male HSDD. An estimated 16 million men the U.S. and Western Europe have low sexual desire which may be HSDD. Like women, men may receive benefits in the areas of desire, arousal and overall sexual satisfaction, with additional benefits likely appearing for the common problems of sexual performance anxiety and treatment-resistant erectile dysfunction.

About S1 Biopharma

S1 Biopharma is a developer of first-in-class drugs for sexual dysfunction in both women and men. The company’s pipeline of therapies is non-hormonal, acting on the sexual centers of the brain by restoring the natural balance of key neurotransmitters. S1 Biopharma’s pipeline utilizes its trademark philosophy of identifying and combining mechanistically opposing agents that work synergistically to maximize beneficial effects on sexual function while minimizing side effects. The company’s lead compound, Lorexys, is currently in a Phase 2a clinical trial for the treatment of hypoactive sexual desire disorder (HSDD).