(LXRX) Positive Top-Line Results For Pivotal Phase 3 Telotristat Etiprate Cancer Study

Telotristat Etiprate has FDA Fast-Track, Orphan Drug Status Conference call and webcast on August 3, 2015 at 8:00 a.m. Eastern Time

THE WOODLANDS, Texas, Aug. 3, 2015 — Lexicon Pharmaceuticals, Inc. (Nasdaq: LXRX) today announced that the pivotal TELESTAR Phase 3 clinical trial met its primary endpoint, showing the benefit of oral telotristat etiprate in treating cancer patients with carcinoid syndrome that is not adequately controlled by the current standard of care. Telotristat etiprate was discovered using Lexicon’s gene science, based on Nobel Prize-winning technology, and is the company’s first discovery to complete a pivotal Phase 3 clinical trial. If approved, telotristat etiprate would be the first oral treatment successfully developed for carcinoid syndrome and the first addition to the standard of care in more than 16 years[1].

Top-line results from the Phase 3 study show that patients who added telotristat etiprate to the standard of care at both the 250 mg and 500 mg doses experienced a statistically significant reduction from baseline compared to placebo in the average number of daily bowel movements over the 12-week study period (p<0.001), meeting the study’s primary endpoint.

“We are extremely pleased with these top-line results,” said Lexicon President and Chief Executive Officer Lonnel Coats. “Carcinoid syndrome is severely debilitating, preventing many patients from leading active and predictable lives, and unfortunately, a majority of patients will not be adequately controlled over time with the current standard of care. We are committed to working closely with the FDA to file our first new drug application (NDA) and to bring this innovative new treatment to patients whose lives are already impacted by the challenges of cancer.”

“The TELESTAR results are promising, and the community of patients and caregivers who live and deal with carcinoid syndrome are excited about the prospect of a new treatment becoming available,” said principal investigator Matthew H. Kulke, M.D., Director, Program in Neuroendocrine and Carcinoid Tumors and Senior Physician, Dana Farber Cancer Institute, and Associate Professor of Medicine, Harvard Medical School.

Lexicon received Fast Track designation and Orphan Drug status for telotristat etiprate from the U.S. Food and Drug Administration (FDA) in 2008 and 2012, respectively. The company plans to announce complete results from the Phase 3 TELESTAR study at an upcoming scientific conference.

About Carcinoid Syndrome

Carcinoid syndrome is a rare disease affecting thousands of patients with neuroendocrine tumors that originate in the gastrointestinal tract and metastasize or spread to the liver or other organs. Overproduction of serotonin within these metastatic neuroendocrine tumor (mNET) cells is a driver of carcinoid syndrome, which is characterized by debilitating diarrhea, facial flushing, abdominal pain, heart valve damage and other serious consequences.  The severe and unpredictable diarrhea associated with carcinoid syndrome has a profound impact on cancer patients’ lives, often preventing them from participating in daily activities.

The current standard of care for carcinoid syndrome is somatostatin analog depot injection (SSA), first approved in 1998. SSA therapy fails to maintain adequate control of carcinoid syndrome for most patients, with many becoming not adequately controlled within the first two years after the therapy is initiated.  Patients with carcinoid syndrome can live for many years with metastatic cancer, requiring the need for long-term treatment options to effectively manage their disease[2].

About TELESTAR

The double-blind Phase 3 study known as TELESTAR (Telotristat Etiprate for Somatostatin Analogue Not Adequately Controlled Carcinoid Syndrome) enrolled 135 patients with carcinoid syndrome which was not adequately controlled on SSA therapy, the current standard of care. The three-arm study evaluated two doses of oral telotristat etiprate – 250 mg and 500 mg, each taken three times daily – against placebo over a 12-week period and measured the reduction from baseline in the average number of daily bowel movements. Patients in both the treatment and placebo arms continued their SSA therapy throughout the study.

Top-line results from TELESTAR show that patients who added telotristat etiprate to the standard of care at both the 250 mg and 500 mg doses experienced a statistically significant reduction from baseline compared to placebo in the average number of daily bowel movements over the 12-week study period (p<0.001), meeting the study’s primary endpoint.

In a key secondary measure, a substantially greater proportion of patients on telotristat etiprate achieved a durable response (44 percent and 42 percent in the 250 mg and 500 mg arms, respectively), defined as at least a 30 percent reduction in daily bowel movements over at least half the days of the study period, as compared to 20 percent response on placebo (p<0.040).

Patients who received 250 mg of telotristat etiprate experienced a 29 percent reduction in the average number of daily bowel movements during the final week (week 12) of the study period compared to baseline, and those in the 500 mg arm experienced a 35 percent reduction, while the placebo group showed a 17 percent reduction. These results are consistent with those seen in the 12-week Phase 2 study of telotristat etiprate.

The proportion of patients with treatment-emergent adverse events (AEs), serious AEs and discontinuation due to AEs were generally similar in all three treatment arms. The tolerability profile of the telotristat etiprate 250 mg dose appeared similar to placebo and somewhat better than the 500 mg dose with respect to gastrointestinal discomfort and mood. The overall incidence and nature of AEs in TELESTAR was consistent with those reported in previous studies. Further in depth analysis of safety and tolerability data will be conducted.

The 12-week study period is being followed by a 36-week open-label extension where all patients receive telotristat etiprate 500 mg three times daily.

About Telotristat Etiprate

Discovered using Lexicon’s unique approach to gene science, telotristat etiprate is the first investigational drug in clinical studies to target tryptophan hydroxylase (TPH), an enzyme that triggers the excess serotonin production within mNET cells that leads to carcinoid syndrome. While existing treatments for carcinoid syndrome work to reduce the release of serotonin outside tumor cells, telotristat etiprate works at the source to reduce serotonin production within the tumor cells. By specifically inhibiting serotonin production, telotristat etiprate seeks to control this important driver of carcinoid syndrome and, in turn, provide patients with more control over their disease.

Lexicon retains rights to market telotristat etiprate in the U.S. and Japan, and is building the in-house commercial infrastructure to serve the U.S. market. The company has a license and collaboration agreement with Ipsen to commercialize telotristat etiprate in Europe and other countries outside the U.S. and Japan.

Lexicon Conference Call

Lexicon management will hold a conference call and webcast to discuss the TELESTAR Phase 3 top-line results at 8:00 a.m. Eastern Time on August 3, 2015.  The dial-in number for the conference call is 888-645-5785 (within the US/Canada) or 970-300-1531 (international).  The conference ID for all callers is 37172080.  Investors can access a live webcast of the call at www.lexpharma.com.  An archived version of the webcast will be available on the website through September 2, 2015.

About Lexicon

Lexicon is a fully integrated biopharmaceutical company that is applying a unique approach to gene science based on Nobel Prize-winning technology to discover and develop precise medicines for patients with serious, chronic conditions. Through its Genome5000™ program, Lexicon scientists have studied the role and function of nearly 5,000 genes over the last 20 years and have identified more than 100 protein targets with significant therapeutic potential in a range of diseases. Through the precise targeting of these proteins, Lexicon is pioneering the discovery and development of innovative medicines to safely and effectively treat disease. Lexicon has a pipeline of promising drug candidates in clinical and pre-clinical development in oncology, diabetes and metabolism. For additional information please visit www.lexpharma.com.

Safe Harbor Statement

This press release contains “forward-looking statements,” including statements relating to Lexicon’s clinical development of telotristat etiprate (LX1032), including characterizations of the results of and projected timing of clinical trials and the potential therapeutic and commercial potential of telotristat etiprate.  In addition, this press release also contains forward-looking statements relating to Lexicon’s growth and future operating results, discovery and development of products, strategic alliances and intellectual property, as well as other matters that are not historical facts or information.  All forward-looking statements are based on management’s current assumptions and expectations and involve risks, uncertainties and other important factors, specifically including those relating to Lexicon’s ability to meet its capital requirements, successfully conduct clinical development of telotristat etiprate and preclinical and clinical development of its other potential drug candidates, obtain necessary regulatory approvals, achieve its operational objectives, obtain patent protection for its discoveries and establish strategic alliances, as well as additional factors relating to manufacturing, intellectual property rights, and the therapeutic or commercial value of its drug candidates, that may cause Lexicon’s actual results to be materially different from any future results expressed or implied by such forward-looking statements.  Information identifying such important factors is contained under “Risk Factors” in Lexicon’s annual report on Form 10-K for the year ended December 31, 2014, as filed with the Securities and Exchange Commission.  Lexicon undertakes no obligation to update or revise any such forward-looking statements, whether as a result of new information, future events or otherwise.

[1] Octreotide acetate for injectable suspension was approved by FDA for the treatment of carcinoid syndrome in 1998.

[2] Shebani KO, Souba WW, Finkelstein DM, et al. (1999). Prognosis and Survival in Patients With Gastrointestinal Tract Carcinoid Tumors. Annals of Surgery. 1999;229(6):815.