BEDMINSTER, NJ ( TheStreet) -- NPS Pharmaceuticals ( NPSP) has two major questions to tackle at next week's FDA advisory panel that will review Gattex for the treatment of patients with short bowel syndrome. 1. Does Gattex cause cancer? 2. Does a reduction in intravenous feeding (but not necessarily a cessation of intravenous feeding) represent a significant and meaningful clinical benefit for patients with short bowel syndrome? The Gattex FDA advisory panel is scheduled for Tuesday, Oct. 16. On Friday, Oct. 12, FDA is expected to release briefing documents for panel including the agency's clinical review of Gattex. NPS Pharma shares closed Wednesday at $9.17. Short bowel syndrome (SBS) is a chronic and disabling condition that strikes people, who for various reasons including Crohn's disease, have about 50% of their lower intestines surgically removed. A majority of patients can adapt to lead normal lives. A smaller group of SBS patients never recover full functionality of their lower intestines, and a result, must spend the rest of their lives attached to an intravenous parenteral nutrition bag that provides the liquid nutrients they need to survive. NPS Pharma estimates approximately 15,000 SBS patients eligible for Gattex in the U.S., meaning the condition qualifies for orphan drug status (and potential premium pricing.) Gattex pricing hasn't been disclosed but drug's U.S. peak sales potential is in the $350 million range. European regulators approved Gattex last month. Takeda will sell the drug in Europe under the brande name Revestive. NPS Pharma receives royalties on Revestive sales. Gattex is an analogue of GLP-2, a protein involved with intestinal growth and function. Administered via a shot under the skin, Gattex is designed to boost the ability of the intestine to absorb nutrients. Approximately 556 SBS patients have been treated with Gattex in all studies. One year ago, NPS Pharma reported three cases of cancer in Gattex-treated SBS patients from a long-term follow-up study. Two of the patients died. Gattex is a growth factor so the three cancer cases raised concerns that the drug may be carcinogenic, particularly when used over long periods. One patient died from a metastatic adenocarcinoma that likely originated in the gastrointestinal tract. This patient was being treated with Gattex for 313 days when the cancer was diagnosed. However, the patient was previously diagnosed with Hodgkin's disease and treated with radiation and chemotherapy. A CT scan taken six months before the patients began taking Gattex revealed a lesion on the liver. The second patient was diagnosed with non-small cell lung cancer 85 days after starting treatment with Gattex. This patient, who also died, was a heavy smoker. The third patient was diagnosed with squamous cell lung cancer after 535 days on Gattex therapy. This patient also had a history of smoking. At the FDA panel, NPS Pharma will argue that the three cancer cases are unrelated to Gattex. Patients in the Gattex study were pre-screened with colonoscopies and any polyps found were removed. At the end of the study, no difference in the number of new polyps was observed between Gattex-treated patients and patients in the placebo arm. None of the new polyps that were found were cancerous.