Table of Contents
- What is POSENACAFTOR?
- How POSENACAFTOR Works
- Clinical Trials
- Eligibility Criteria
- Potential Benefits
- Safety and Side Effects
- Administration
What is POSENACAFTOR?
POSENACAFTOR, also known as PTI-801, is a promising new medication being studied for the treatment of cystic fibrosis (CF)[1]. Cystic fibrosis is a genetic disorder that affects the lungs, digestive system, and other organs, causing thick, sticky mucus to build up and leading to various health problems.
This drug is part of a combination therapy that includes two other medications: dirocaftor and nesolicaftor. Together, these three drugs are being tested to see how well they can help people with CF, especially those with rare genetic mutations that cause the disease[2].
How POSENACAFTOR Works
POSENACAFTOR belongs to a class of drugs called CFTR modulators. CFTR stands for Cystic Fibrosis Transmembrane Conductance Regulator, which is the protein that is faulty in people with CF. This medication works by helping the CFTR protein function better, which can improve the symptoms of cystic fibrosis[1].
Clinical Trials
POSENACAFTOR is currently being studied in clinical trials to evaluate its effectiveness and safety. Two important studies are underway:
- A Phase III trial called CHOICES, which is testing the combination of dirocaftor, posenacaftor, and nesolicaftor in adults with CF who are 18 years or older[1].
- A Phase IIb trial, also called CHOICES, which is similar to the Phase III trial but focuses on specific groups of CF patients[2].
Both trials are designed to be multicentre, randomized, double-blind, and placebo-controlled. This means that the studies are being conducted at multiple hospitals or clinics, participants are randomly assigned to either receive the medication or a placebo (a substance with no active ingredients), and neither the patients nor the researchers know who is receiving which treatment until the study is complete.
Eligibility Criteria
To participate in these clinical trials, patients must meet certain criteria. Some key requirements include:
- Being 18 years of age or older
- Having a confirmed diagnosis of cystic fibrosis
- Having stable CF disease
- Having a lung function (FEV1) between 40% and 90% of predicted normal values
- Not currently taking other CFTR modulators
- Not having certain common CF mutations (like F508del)
It’s important to note that these are just some of the criteria, and there are additional requirements and exclusions[1][2].
Potential Benefits
The clinical trials are measuring several outcomes to determine how well POSENACAFTOR and its companion drugs work. Some potential benefits being studied include:
- Improved lung function, measured by FEV1 (Forced Expiratory Volume in 1 second, which is the amount of air a person can forcefully exhale in one second)
- Reduced sweat chloride levels (a key indicator of CF severity)
- Increased body weight
- Improved quality of life, as measured by a special questionnaire for CF patients
These outcomes are being measured after 4, 6, and 8 weeks of treatment to see how quickly and effectively the medication works[1][2].
Safety and Side Effects
As with any new medication, researchers are carefully monitoring the safety of POSENACAFTOR. The clinical trials are tracking any side effects or adverse events that occur during treatment. This includes monitoring through:
- Regular blood tests
- Physical examinations
- Electrocardiograms (ECGs) to check heart function
- Vital sign measurements
It’s important to remember that the full safety profile of POSENACAFTOR is still being established through these clinical trials[2].
Administration
POSENACAFTOR is being tested as an oral medication in the form of a hard capsule. In the clinical trials, the maximum daily dose being tested is 600 mg. The treatment period in the studies lasts up to 16 weeks[1][2].
It’s important to note that POSENACAFTOR is still an investigational drug and is not yet approved for general use. If you have cystic fibrosis and are interested in this treatment, you should discuss it with your healthcare provider to see if participating in a clinical trial might be appropriate for you.


