Human Secretin

ChiRhoStim ® is indicated for the stimulation of: pancreatic secretions, including bicarbonate, to aid in the diagnosis of pancreatic exocrine dysfunction. gastrin secretion to aid in the diagnosis of gastrinoma, and pancreatic secretions to facilitate the identification of the ampulla of Vater and accessory papilla during endoscopic retrograde cholangiopancreatography (ERCP). ChiRhoStim® is a secretin class hormone indicated for stimulation of: pancreatic secretions, including bicarbonate, to aid in the diagnosis of exocrine pancreas dysfunction (1) gastrin secretion to aid in the diagnosis of gastrinoma (1) pancreatic secretions to facilitate the identification of the ampulla of Vater and the accessory papilla during endoscopic retrograde cholangiopancreatography (ERCP) (1)

For injection: 16 mcg or 40 mcg of human secretin as a white lyophilized powder in single-dose vial for reconstitution. For injection: 16 mcg or 40 mcg of human secretin as a lyophilized powder in single-dose vial for reconstitution (3)

None. None (4)

Patients with alcoholic or other liver disease may be hyperresponsive to stimulation with ChiRhoStim®, masking the presence of coexisting pancreatic disease. Consider additional testing and clinical assessments for aid in diagnosis. ​​ Hyporesponse to Secretin Stimulation Testing in Patients with Vagotomy, Inflammatory Bowel Disease or Receiving Anticholinergics : Discontinue anticholinergic drugs at least 5 half-lives prior to stimulation testing; consider additional testing and clinical assessments for aid in diagnosis. (2.1, 5.1, 7.1) Hyperresponse to Secretin Stimulation Testing : Increased gastrin secretion in patients receiving H 2 -receptor antagonists or PPIs falsely suggesting gastrinoma; discontinue co-administered drug prior to stimulation testing. Increased pancreatic secretions in patients with alcoholic or other liver disease masking coexisting pancreatic disease; consider additional testing and clinical assessments for aid in diagnosis. (2.1, 5.2, 7.2)

6.1 Clinical Trials Experience Because clinical trials are conducted under varying conditions, adverse reaction rates observed during the clinical trials of a drug cannot always be directly compared to the rates observed during the clinical trials of another drug and may not reflect the adverse reaction rates observed in practice. The data described below reflect exposure to ChiRhoStim® in 531 patients from an open-label clinical trial. The population consisted of patients aged 1 to 91 years, 185 males, 346 females, 480 Caucasians, 31 Blacks, 12 American Indians, 6 Hispanics, and 2 Asians with known or suspected diseases of the exocrine pancreas including chronic pancreatitis and pancreatic cancer. Most patients received a single dose of ChiRhoStim® in a dose range of 0.2 mcg/kg to 0.4 mcg/kg. The most common adverse reactions (reported in at least 2 patients in the trial) are listed in Table 2. TABLE 2 Adverse Reactions in at Least 2 Patients Treated with a Single-Dose of ChiRhoStim® in a Clinical Trial Adverse Reaction ChiRhoStim® Number of Patients N = 531 Nausea 9 Vomiting 3 Flushing 2 Upset stomach 2 Most common adverse reactions (≥2 patients) are nausea, vomiting, flushing, and upset stomach. (6.1) To report SUSPECTED ADVERSE REACTIONS, contact ChiRhoClin, Inc. at 1-877-272-4888 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. See 17 for PATIENT COUNSELING INFORMATION. Revised: 07/2017

7.1 Hyporesponse with Anticholinergics The concomitant use anticholinergic drugs may cause a hyporesponse to stimulation testing with ChiRhoStim ® . Discontinue anticholinergic drugs at least 5 half-lives before administering ChiRhoStim ® [see Dosage and Administration (2.1)] .

7.2 Hyperresponse of Gastrin Secretion with H 2 -Receptor Antagonists and PPIs The concomitant use of H 2 -receptor antagonists or PPIs may cause a hyperresponse in gastrin secretion in response to stimulation testing with ChiRhoStim ® , falsely suggesting gastrinoma. Discontinue H 2 -receptor antagonists at least 2 days before administering ChiRhoStim ® to aid in the diagnosis of gastrinoma. The time it takes for serum gastrin concentrations to return to baseline following discontinuation of PPIs is specific to the individual drug. Consult the prescribing information of each specific PPI before administering ChiRhoStim ® to aid in the diagnosis of gastrinoma.

8.1 Pregnancy Risk Summary There are no available data (either clinical studies or postmarketing reports) of use of synthetic human secretin in pregnant women. Animal reproduction studies have not been conducted with synthetic human secretin. The estimated background risk of major birth defects and miscarriage for the indicated populations are unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively.

8.2 Lactation Risk Summary There are no data on the presence of synthetic human secretin in human or animal milk, the effects of synthetic human secretin on the breastfed infant, or the effects of synthetic human secretin on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for ChiRhoStim ® and any potential adverse effects on the breastfed infant from ChiRhoStim ® or from the underlying maternal condition.

8.4 Pediatric Use The safety and effectiveness of ChiRhoStim ® in pediatric patients have not been established.

8.5 Geriatric Use Among the 531 patients who have received ChiRhoStim ® in a clinical trial, 11% were 65 years of age or older and 5% were 75 years of age or older. No overall differences in safety, pharmacologic response, or diagnostic effectiveness were observed between these subjects and younger subjects, and other reported clinical experience has not identified differences in responses between the elderly and the younger patients, but greater sensitivity of some older individuals cannot be ruled out.

12.1 Mechanism of Action The primary action of ChiRhoStim ® is to stimulate pancreatic ductal cells to secrete pancreas fluid in large volumes that contain bicarbonate. Secretin is a hormone that is normally released from the duodenum upon exposure of the proximal intestinal lumen to gastric acid, fatty acids and amino acids. Secretin is released from enterochromaffin cells in the intestinal mucosa. Secretin receptors have been identified in the pancreas, stomach, liver, colon and other tissues. When secretin binds to secretin receptors on pancreatic duct cells it opens cystic fibrosis transmembrane conductance regulator (CFTR) channels, leading to secretion of bicarbonate-rich-pancreatic fluid. Secretin may also work through vagal-vagal neural pathways since stimulation of the efferent vagus nerve stimulates bicarbonate secretion and atropine blocks secretin-stimulated pancreatic secretion.