Comparing Pancreatic Enzyme Products for Patients with Cystic Fibrosis

A trial of the pancrelipase formulation Zenpep found the product to be as safe and effective as Creon for the treatment of exocrine pancreatic insufficiency in cystic fibrosis patients aged 12 years and older.

Investigators randomized 96 patients (mean baseline age, 19.2 years; 60.4% male) between the 2 products and then switched patients from 1 product to the other halfway through the trial. All patients were on stabilized treatment plans and ate standardized diets throughout the trial, which compared 25,000 lipase-unit doses of the 2 time-released enzyme supplements.

In all, 83 of the patients completed both sequences of the trial, which used coefficient of fat absorption over 72 hours as its primary efficacy endpoint. Analysis of lab test results found the least squared mean for the coefficient of fat absorption to be 84.1% (SE, 1.1) among Zenpep users and 85.3% (SE, 1.1) among Creon users (p = 0.297).

“Zenpep is comparable with Creon in efficacy and safety for the treatment of adolescents and adults with cystic fibrosis-associated exocrine pancreatic insufficiency,” the study authors wrote in the Journal of Cystic Fibrosis.

Zenpep — like Creon, Pancreaze, Ultresa, Viokace and Pertzyle — contains a mixture of digestive enzymes (including lipases, proteases, and amylases) extracted from pig pancreases and used to help people with exocrine pancreatic insufficiency digest fats, proteins and sugars.

Such products had been available without a prescription for decades, but there was little research to demonstrate the safety and efficacy of individual brands, which were sold without approval from the US Food and Drug Administration (FDA).

In the early 1990s, however, the FDA decided to act upon reports that enzyme quantities varied so much from pill to pill that patients faced frequent problems with both under-dosing and over-dosing. The agency eventually announced that all companies that wished to continue selling pancrelipase in the U.S. would have to submit new drug applications for their products by 2008 — a decision that spurred a wave of pancrelipase trials that continues to this day.

All of the available pancreatic enzyme products (PEPs) are similar, but the FDA warns that they are not interchangeable with each other, let alone any unapproved product that patients may be using.

“Recognize that the labeled contents of FDA-approved PEPs reflect the actual enzyme content of the product, whereas the labeled contents of unapproved PEPs underestimate the actual lipase content,” the agency urges in its recommendations to healthcare providers.

“When switching a patient to another PEP, consider starting with a similar amount of lipase enzyme, then adjust the dose based on the patient's response. Recognize that it may take 1-2 weeks for a patient to adjust their dose of the new PEP. Individual patient response should be monitored when switching from an unapproved PEP to an approved one.”

Anecdotal data online supports the FDA’s position. Patients who post to message boards frequently report that different products produced dramatically different results for themselves or their loved ones. That said, no single product seems to work best for everyone. A switch from 1 product to another can dramatically improve digestion and reduce gastrointestinal distress for 1 patient, while a switch in the opposite direction may do the same for another.