Steps in the Journey: CFTR mutation to sweat chloride concentration to survival

Associations between “salty” sweat and early mortality can be found in the scientific literature dating back to the 17th century [1], hundreds of years before a comprehensive medical description of cystic fibrosis (CF) [2]. Insightful observation of excessive dehydration and deaths among children during a 1948 New York City heat wave suggested that salt homeostasis was a fundamental cellular problem in CF [3], with identification of supranormal sweat chloride concentrations remaining fundamental to the diagnosis of CF today. Since identification of the mutated gene associated with CF (the cystic fibrosis transmembrane conductance regulator; CFTR) [4], pieces of the CF puzzle seem to have, for the most part, fallen into place. Continue reading Steps in the Journey: CFTR mutation to sweat chloride concentration to survival

Vitamin D3 deficiency and its association with nasal polyposis in patients with cystic fibrosis

This trial ascertained if the deficiency of vitamin D3 (VD3) correlated with the presence of nasal polyposis (NP) in patients with cystic fibrosis (CF) and patients with chronic rhinosinusitis (CRS). VD3 deficiency appeared to be related to the presence of nasal polyps in the patients with CRS and in the patients with CF in a similar manner. It was inferred that the lower the level of serum VD3, the more severe the mucosal disease was disclosed in the imaging studies and the more frequent microbial colonization of the patients with CF and the patients with CRS. Continue reading Vitamin D3 deficiency and its association with nasal polyposis in patients with cystic fibrosis

Therapy for Reducing P. Aeruginosa Lung Infections Planned Phase 1 Trial

Arch Biopartners recently completed a good manufacturing practice (GMP) production campaign for AB569, a potential inhalation treatment for antibiotic-resistant bacterial lung infections in people with cystic fibrosis (CF) chronic obstructive pulmonary disease (COPD) and other conditions. The campaign, intended to ensure the quality of the investigative therapy, was directed by Dalton Pharma Services.

AB569 is composed of ethylenediaminetetraacetic acid (EDTA) and sodium nitrite, two compounds approved by the U.S. Food and Drug Administration (FDA) for use in people. AB569 can be administered alone or in combination with other compounds to treat multi-drug resistant bacterial infections that can cause reduced lung function.

Pseudomonas aeruginosa is one of the most common bacterial infections in patients with respiratory diseases, including CF, COPD, and pneumonia.

In preclinical studies, AB569 was shown to be capable of killing drug-resistant bacteria like P. aeruginosa and other common pathogens associated with chronic lung infections.

The company also announced that a Phase 1 clinical trial to investigate the safety and pharmacokinetic profile of AB569, planned to start in January, will be conducted at the Cincinnati Veterans Affairs Medical Center (CVAMC). According to an Arch Biopartners press release, Ralph Panos, chief of medicine at CVAMC, will lead the trial.

Three escalating doses of nebulized AB569 will be used to evaluate tolerance to the treatment in about 25 healthy volunteers. Each will be given a single administration of nebulized AB569  to characterize the pharmacokinetic profile of plasma nitrite and nitrate metabolites, exhaled nitric oxide, and circulating hemoglobin.

Pharmacokinetics studies how a drug is absorbed, distributed and metabolized in, and expelled by, the body.

Should the Phase 1 trial in volunteers be successful, Arch Biopartners plans to move its AB569 program into a Phase 2 trial to test its effectiveness in treating chronic P.aeruginosa infections in COPD patients.

AB569 received orphan drug status by the FDA in November 2015 as a potential treatment of P. aeruginosa lung infections in CF patients. Orphan drug status is given to investigative medicines intended for people with rare diseases to speed their development and testing.

Original article: https://cysticfibrosisnewstoday.com/2017/12/12/arch-biopartners-readies-ab569-potential-treatment-for-cf-copd-lung-infections-for-phase-1-trial/

A Breath of Fresh Air for Biotechs Working on Cystic Fibrosis Therapies

Researchers from the University of Zurich have determined the structure of a chloride channel, which could be a target for new drugs to treat cystic fibrosis.

Researchers at the University of Zurich have found a new target for future cystic fibrosis treatments. The study, published in Nature, has uncovered the structure of a protein that could help to correct the mechanism underlying the buildup of sticky mucus in patients’ lungs. This could give rise to a new wave of therapeutics for the condition, which at the moment lacks disease-modifying treatments.

Cystic fibrosis is a severe genetic disease affecting the lungs, for which there is currently no cure. It is caused by a malfunctioning chloride channel, CFTR, which prevents the secretion of chloride by cells, leading to the production of thick, sticky mucus in the lung. The condition affects around 70,000 people worldwide, who suffer from chronic infections and require daily physiotherapy.

However, one potential approach to treat cystic fibrosis is to activate the calcium-activated chloride channel, TMEM16A, as an alternative route for chloride efflux. As TMEM16A is located within the same epithelium as CFTR, its activation could rehydrate the mucus layer. The research group used cryo-electron microscopy to decipher the structure of TMEM16A, which is part of a protein family that facilitates the flow of negatively charged ions or lipids across the cell membrane.

The changes that occur in the lungs of cystic fibrosis patients.

TMEM16A is found in many of our organs, playing a key role in muscle contraction and pain perception, as well as in the lungs. It forms an hourglass-shaped protein-enclosed channel, which when bound by positively charged calcium ions, opens to let chloride ions to pass through the membrane.

Current treatments for cystic fibrosis include bronchodilators, mucus thinners, antibiotics, and physiotherapy, which only control symptoms. However, biotechs around Europe are beginning to make progress, with ProQR completing a Phase Ib trial and Galapagos and Abbvie’s triple combination therapy entering Phase I. Antabio has also received €7.6M from CARB-X to develop a new antibiotic against Pseudomonas infections.

The identification of a new target provides patients and biotechs alike with renewed hope of new and effective cystic fibrosis treatments, or even a cure. It will be interesting to see whether small molecules or gene therapy specialists could take advantage of this information.

Original article: https://labiotech.eu/cystic-fibrosis-treatment-target/

Cancer gene plays key role in cystic fibrosis lung infections

PTEN is best known as a tumor suppressor, a type of protein that protects cells from growing uncontrollably and becoming cancerous. But according to a new study from Columbia University Medical Center (CUMC), PTEN has a second, previously unknown talent: working with another protein, CFTR, it also keeps lung tissue free and clear of potentially dangerous infections.

The findings, published in Immunity, explain why people with cystic  are particularly prone to respiratory infections—and suggest a new approach to treatment.

A quarter-century ago, researchers discovered that cystic fibrosis is caused by mutations in the CFTR gene, which makes an eponymous protein that transports chloride ions in and out of the cell. Without ion transport, mucus in the lung becomes thicker and stickier and traps bacteria—especially Pseudomonas—in the lung. The trapped bacteria exacerbate the body’s inflammatory response, leading to persistent, debilitating infections.

But newer research suggests CFTR mutations also encourage infections through a completely different manner.

“Recent findings suggested that  with CFTR mutations have a weaker response to bacteria, reducing their ability to clear infections and augmenting inflammation,” said lead author Sebastián A. Riquelme, PhD, a postdoctoral fellow at CUMC. “This was interesting because it pointed to a parallel deregulated immune mechanism that contributes to airway destruction, beyond CFTR’s effect on mucus.”

That’s where PTEN comes into play. “We had no idea that PTEN was involved in cystic fibrosis,” said study leader Alice Prince, MD, professor of pediatrics (in pharmacology). “We were studying mice that lack a form of PTEN and noticed that they had a severe inflammatory response to Pseudomonas and diminished clearance that looked a lot like what we see in patients with cystic fibrosis.”

Delving deeper, the CUMC team discovered that when PTEN is located on the surface of lung and immune cells, it helps clear Pseudomonas bacteria and keeps the inflammatory response in check. But PTEN can do this only when it’s attached to CFTR.

And in most cases of cystic fibrosis, little CFTR finds it way to the cell surface. As a result, the duo fail to connect, and Pseudomonas run wild.

As it happens, the latest generation of cystic fibrosis drugs push mutated CFTR to the cell surface, with the aim of improving chloride channel function and reducing a buildup of mucus. The new findings suggest that it might be beneficial to coax nonfunctional CFTR to the surface as well, since even abnormal CFTR can work with PTEN to fight infections, according to the researchers.

“Another idea is to find drugs that improve PTEN membrane anti-inflammatory activity directly,” said Dr. Riquelme. “There are several PTEN promotors under investigation as cancer treatments that might prove useful in cystic fibrosis.”

The study also raises the possibility that PTEN might have something to do with the increased risk of gastrointestinal cancer in . “With better clinical care, these patients are living much longer, and we’re seeing a rise in gastrointestinal cancers,” said Dr. Prince. “Some studies suggest that CFTR may be a tumor suppressor. Our work offers an alternative hypothesis, where CFTR mutations and lack of its partner, PTEN, might be driving this cancer in patients with .”

The paper is titled, “Cystic fibrosis transmembrane conductance regulator attaches tumor suppressor PTEN to the membrane and promotes anti Pseudomonas aeruginosa immunity.”

For journal article click here:

http://www.cell.com/immunity/fulltext/S1074-7613(17)30487-9

New Promising Results from Phase 3 of Combination Therapy

Findings from a phase 3 trial evaluating the efficacy and safety of tezacaftor in combination with ivacaftor in patients with cystic fibrosis (CF) who were homozygous for the Phe508del mutation were published in the New England Journal of Medicine.

The Phe508del mutation has been known to result in greatly reduced conductance regulator (CFTR) protein activity and a loss of chloride secretion, which can lead to impaction of mucus in the airways, gastrointestinal tract, and exocrine organs, with the potential for severe clinical consequences including gradual loss of lung function, nutritional deficits, pulmonary exacerbations, and respiratory failure. It is the most prevalent CFTR mutation worldwide, and affects approximately 46% of American CF patients.

Previous data has shown Ivacaftor’s association with a rate of progressive decline in lung function that is lower than that in untreated patients. In a phase 2 clinical trial involving patients who were homozygous for the Phe508del mutation or heterozygous for the Phe508del and G551D mutations, when combined with the investigational CFTR corrector tezacaftor, it has exhibited enhanced CFTR function and improved lung function.

In August, just one month removed from Vertex’s announcement of positive datafrom Phase 1 and Phase 2 studies, Rare Disease Report covered the acceptance of applications for the use of the tezacaftor/ivacaftor combination treatment in this patient population by the U.S. Food and Drug Administration (FDA) and European Medicines Agency (EMA).

The phase 3 trial enrolled a total of 510 patients 12 years and older with CF who were homozygous for the Phe508del CFTR mutation at 91 sites in the U.S., Canada, and Europe from January 30, 2015 to January 20, 2017. Patients were randomly assigned to be administered either tezacaftor and ivacaftor (administered as a fixed-dose combination tablet containing 100 mg of tezacaftor and 150 mg of ivacaftor in the morning and a tablet containing 150 mg of ivacaftor in the evening) combination therapy or placebo for 24 weeks.

In total, 475 patients completed the full 24 weeks of the trial, with 93.6% (n=235) in the tezacaftor-ivacaftor group and 93% (n=240) in the placebo group. While no significant difference in the body mass index (BMI) was experienced between the groups at week 24, the use of the combination therapy led to a significantly greater absolute change from baseline in the predicted forced expiratory volume in 1 second (FEV1) than placebo. Despite advances in standard-of-care therapy, patients with CF continue to lose lung function at a rate of an estimated 1% to 3% per year. This trial exhibited a significant effect of the combination therapy compared to the placebo, as the mean absolute change from baseline in FEV1 through week 24 was 3.4 percentage points in the former, compared to 0.6 in the latter.

The most common adverse events (AEs) among the enrolled patients included infective pulmonary exacerbation, cough, headache, nasopharyngitis, increased sputum production, pyrecia, hemoptysis, oropharyngeal pain, and fatigue. The incidence of AEs was similar in both the group for combination therapy and the placebo group, however, those treated with lumacaftor-ivacaftor in the phase 3 did not experience an increased incidence of respiratory events (33 patients [13.1%] vs. 41 patients [15.9%]).

This improved safety profile of the tezacaftor-ivacaftor combination supports its use in a broad range of patients with CF, and, if approved, the therapy will be the third of Vertex’s drugs approved for CF patients, and the second intended specifically to treat patients with F508del mutations (Orkami [lumacaftor/ivacaftor]).

For original article please visit: http://www.raredr.com/news/phase-3-combination-therapy-cystic-fibrosis?t=physicians

For the published study please visit: http://www.nejm.org/doi/full/10.1056/NEJMoa1709846?query=genetics#t=articleDiscussion

Study Links PPI Use to Treat Gastroesophageal Reflux with More Frequent Hospitalizations

Doctors should frequently re-evaluate the use of protein pump inhibitors (PPIs) for cystic fibrosis (CF) patients, urges a University of Florida study which warns that long-term PPI use leads to a higher risk of hospitalization for pulmonary exacerbations.

Identifying risk factors associated with pulmonary exacerbations is critical since they cause a decline in pulmonary function and survival rates among CF patients.

PPI use, in particular, is believed to cause community-acquired pneumonia (CAP). Even though most CF patients use PPIs to control gastroesophageal reflux (GER), scientists still don’t fully understand the link between PPIs and pulmonary exacerbations in CF.

In the study, “Proton Pump Inhibitor Use Is Associated With an Increased Frequency of Hospitalization in Patients With Cystic Fibrosis,” which appeared in the journal Gastroenterology Research, researchers investigated that link and the risks it entails.

The study involved 114 adults who had been seen at UF’s Adult Cystic Fibrosis Center in Gainesville, Florida, between January and December 2016. Researchers collected data on PPI use and hospitalization during a one-year follow-up.

Results showed that 59 of the 114 patients (51.7 percent) used PPI for six or more months, and that exactly the same proportion (51.7 percent) had been hospitalized at least once during the one-year follow-up period. Among those who were hospitalized, PPI use was closely linked with the number of hospitalizations for pulmonary exacerbation, though researchers observed no link between frequency of hospitalization and PPI dosage.

No significant difference was found in GER between hospitalized and non-hospitalized patients.

The UF study is limited, in that it’s retrospective and therefore doesn’t establish a cause-effect relationship between PPIs and pulmonary exacerbation. Researchers say there’s still a possibility that GER itself — rather than the subsequent use of PPIs — causes increased pulmonary exacerbations. Yet they point out that the prevalence of GER was similar among hospitalized and non-hospitalized patients, supporting a causative link between PPI and pulmonary exacerbations.

Based on their findings, the UF team suggests that “prescribers of PPI therapy should exercise pharmacovigilance; frequently re-evaluating indications and appropriateness of therapy and in the setting of GER considering alternate management modalities such as anti-reflux surgery where appropriate.”

For original article please visit: https://cysticfibrosisnewstoday.com/2017/12/07/proton-pump-inhibitor-use-is-associated-with-an-increased-frequency-of-hospitalization-in-patients-with-cystic-fibrosis/

Trial to Possibly Treat Nonesense Mutations Begins

Sevion Therapeutics and Eloxx Pharmaceuticals announced that a first healthy subject has been dosed in a Phase 1b clinical trial assessing the safety, tolerability and drug properties of ELX-02 as a potential treatment of several genetic diseases caused by nonsense mutations, including cystic fibrosis (CF).

Continue reading Trial to Possibly Treat Nonesense Mutations Begins

A Brief Historical Timeline of CF Research to Date

Cystic fibrosis care has seen such rapid advances that the average CF patient has experienced a dramatic evolution in treatment strategies in their lifetime. Here are some of the biggest milestones that shaped modern-day CF treatments.

Continue reading A Brief Historical Timeline of CF Research to Date

Positive Results for Phase 3 Studies of the Tezacaftor/Ivacaftor Combination Treatment

Vertex Pharmaceuticals Incorporated (Nasdaq: VRTX) announced that the New England Journal of Medicine (NEJM) published two articles with results from two Phase 3 studies of the tezacaftor/ivacaftor combination treatment, a medicine in development that is designed to treat the underlying cause of cystic fibrosis (CF) in people ages 12 and older who have certain mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Continue reading Positive Results for Phase 3 Studies of the Tezacaftor/Ivacaftor Combination Treatment