Although PN can provide nutritional support for SBS patients, it does not improve the body's own ability to absorb nutrients. PN is associated with serious complications, such as infections, blood clots or liver damage, and the risks increase the longer patients are on PN. Patients on PN often experience poor quality of life with difficulty sleeping, and frequent urination, and patients receiving chronic PN often experience a loss of independence.
Gattex Clinical Trials
NPS’ clinical development program for Gattex is the largest and most comprehensive conducted in SBS patients to date, consisting of 15 clinical studies. Across all clinical studies, 566 subjects were exposed to at least one dose of Gattex, of whom 134 had SBS and were treated with 0.05 mg/kg/day Gattex. The FDA’s approval of Gattex was based on an international, 24-week, double-blind, placebo-controlled, pivotal Phase 3 trial, known as STEPS. The primary endpoint of STEPS was defined as a 20 percent or greater PN/IV volume reduction demonstrated at week 20 and sustained at week 24. The study's secondary endpoints included reductions in PN/IV volume and additional days off therapy. Key findings from the STEPS trial include:
- In an intent-to-treat analysis at weeks 20 and 24, 63 percent of patients treated with Gattex achieved at least a 20 percent reduction in weekly PN/IV volume when compared to baseline, versus 30 percent for placebo (p=0.002).
- After 24 weeks of treatment, PN volume declined by 32 percent (4.4 L/wk) in Gattex-treated patients, versus 21 percent (2.3 L/wk) in the placebo group (p<0.001).
- After 24 weeks of treatment, 54 percent of Gattex-treated patients were able to reduce the number of infusion days per week by one or more days, compared to 23 percent of those treated with placebo (p =0.005).
The most common adverse reactions (≥10 percent) across all studies with Gattex are abdominal pain, injection site reactions, nausea, headaches, abdominal distension, upper respiratory tract infection. In addition, vomiting and fluid overload were reported in the Phase 3 SBS studies at rates ≥ 10 percent.