Celtaxsys Inc. Receives $5M Research Award to Advance Once Daily, Oral Anti-Inflammatory Medicine into Phase 2 CF Patient Lung Function Preservation Trial

ATLANTA, (June 2, 2015 — Celtaxsys, a clinical stage drug development company focused on advancing care
for patients suffering from inflammatory diseases, including those with rare and orphan inflammatory diseases,
announced today that it has received a development award for $5 million from Cystic Fibrosis Foundation Therapeutics,
Inc. (“CFFT”), the non-profit drug discovery and development affiliate of the Cystic Fibrosis Foundation
The development award will help support a Phase 2 clinical trial of the Company’s lead development candidate,
a once daily, oral anti-inflammatory drug CTX-4430 in adults with cystic fibrosis (“CF”). CTX-4430 is a selective
inhibitor of Leukotriene A4 Hydrolase that targets re-balancing of a patient’s over activated inflammatory
response without increasing susceptibility to infection. CTX-4430 has been granted orphan status for CF in both
the US and the EU.
“We are grateful for the support of CFFT and the many leading researchers in CF who have helped us design a
trial to assess the benefits of chronic anti-inflammatory therapy in CF patients. Our Phase 1 CTX-4430 studies,
including the study in CF patients, demonstrated that CTX-4430 is well tolerated. Importantly, in only two weeks
in CF patients, CTX-4430 demonstrated positive results on well-established CF biomarkers, including encouraging
reductions in sputum neutrophils, one of the primary “bad actors” in the CF lung that clogs the airways of CF
patients. “In addition, CTX-4430 demonstrated a statistically significant reduction versus placebo in neutrophil
elastase which has been shown to predict the onset of bronchiectasis and which can degrade CFTR and other
protective proteins,” said Greg Duncan, Chief Executive Officer of Celtaxsys, Inc.
“The Celtaxsys team is delighted by CFFT’s decision to help fund this study and believe CTX-4430 could represent
an important new medicine for people with cystic fibrosis, either alone or in conjunction with other therapies,
irrespective of the patient-specific CF gene mutation. We believe CTX-4430’s ability to reduce neutrophil
elastase in the airways of CF patients has the potential to boost the effect of other important existing treatment
regimens, including CFTR modulators and airway clearance therapies,” added Eric Springman, PhD, Chief
Scientific Officer at Celtaxsys.
Principal investigators for the trial in the U.S. and EU, respectively include: Steven M. Rowe, MD, MSPH, Professor
in the Division of Pulmonary, Allergy and Critical Care Medicine and Director of the Center for CFTR Detection
at the University of Alabama at Birmingham School of Medicine, and Professor Stuart Elborn, CBE, Dean School
of Medicine, Dentistry and Biomedical Sciences and Professor of Respiratory Medicine at Queens University
Belfast and Consultant Physician in the Adult CF Centre at Belfast City Hospital. Each have played central roles
in helping to design this potentially ground breaking study. “These two world-class thought leaders spearheaded
important innovations in CFTR research and are now advancing efforts towards anti-inflammatory research, one
of the next frontiers in CF research as identified by the CFFT,” commented Sanjeev Ahuja, MD, Chief Medical
Officer at Celtaxsys.

Celtaxsys will submit its Phase 2 clinical trial protocol for the treatment of CF with CTX-4430 to the U.S. Food
and Drug Administration (“FDA”) this quarter and anticipates beginning this study in the second half of 2015,
pending FDA approval of the protocol.
About Cystic Fibrosis: Cystic fibrosis (CF) is a life-threatening disease that affects the lung and digestive system
and impacts about 70,000 patients worldwide. CF is caused by mutations in the Cystic Fibrosis Transmembrane
conductance Regulator (CFTR) gene leading to abnormal CFTR protein functioning, the result of which causes
the body to accumulate excessive levels of unusually thick mucus in the lungs. This excessive sticky mucus in
the lungs is a site for infections that can require hospitalization. In the pancreas and GI tract CFTR protein
dysfunction results in malabsorption of nutrients and sometimes intestinal blockage. Respiratory distress in CF,
defined as acute difficulty in breathing, infection and/or hospitalization, is most commonly related to lung infection
and inflammation induced lung tissue damage attributable to an overwhelming and dysfunctional response
by deregulated neutrophils. Treatment of this lung inflammation is, therefore, thought to be key to improving CF
patients’ lung health and well-being. For more information on cystic fibrosis, go to
About CTX-4430: CTX-4430 is a once-daily oral drug candidate currently undergoing clinical trials for inflammatory
diseases. It is a novel small molecule inhibitor of Leukotriene A4 Hydrolase (LTAH4), the key enzyme in the
production of the potent inflammatory mediator Leukotriene B4 (LTB4). LTA4H and LTB4 have been strongly
implicated in the pathogenesis of many diseases involving inflammation, including cystic fibrosis.
About Celtaxsys: Celtaxsys is a privately-held drug discovery and development company focused on advancing
medicine to treat patients suffering from serious inflammatory diseases. The company is building a sustainable
pipeline of first-in-class immuno-modulators, the most advanced of which is CTX-4430. Our follow-on molecules
enable new intellectual property and exhibit differentiated properties that enable optimization for alternate routes
of administration. For more information, visit