Efficacy and Safety of Inhaled Nitric Oxide (NO) in Cystic Fibrosis (CF) Patients

This is a multi-center, randomized, placebo controlled, phase II clinical study comparing an
investigational drug to a placebo control. Screening data will be reviewed to determine
subject eligibility. All subjects including screen failure subjects will be recorded on
screening logs at their respective sites. Upon successful completion of all screening
procedures, a subject will be considered eligible for enrollment. The subject will be
enrolled and randomized in as close a time proximity to the first treatment application as is
possible in order to minimize the possibility of dropout while enrolled but before undergoing
treatment. With a 1:1 investigational treatment to placebo control, subjects will be
randomized to one of the two arms. Subjects in the investigational treatment arm will be
administered doses of NO (0.5% NO in 99.5% nitrogen) diluted in room air by inhalation four
times daily (30-minute inhalations at least 3 hours apart) for 7.5 days on Days 1, 2, 3, 4,
5, 8, 9, and 10 (three treatments on Days 1 and 10). Subjects in the placebo arm will breathe
100% nitrogen diluted in room air in the same proportion as the investigational arm. Subjects
will remain in the clinic for 30 minutes after completing the last treatment of each day. All
subjects will be asked to return to the clinic for additional evaluations on Days 15 and 36.

Inclusion Criteria:

1. Confirmed diagnosis of Cystic Fibrosis based on the following criteria:

- positive sweat chloride 60 mEq/liter (by pilocarpine iontophoresis); and/or

- a genotype with two identifiable mutations consistent with CF

2. Presence of Pseudomonas aeruginosa, Staphylococcus aureus or Stenotrophomonas
maltophilia in the screening sputum culture.

3. Chronic microbial lung colonization (≥6 months) with presence of Pseudomonas
aeruginosa, Staphylococcus aureus or Stenotrophomonas maltophilia in at least two (2)
sputum cultures in the past year (the screening culture can count as one of the two
positive cultures).

4. Ongoing chronic inhaled antibiotic therapy for at least 3 months prior to (screening
or baseline).

• For subjects on cycled therapy, at least 2 cycles of drug need to have been
completed prior to baseline.

5. Willing to be off of inhaled antibiotic therapy from Day 1 to Day 15

6. Male or female subjects ≥18 years

7. FEV1 <85% and >35% at screening and baseline

8. SaO2 >90% on room air at screening and baseline

9. Clinically stable with no significant changes in health status within 14 days prior to
Baseline

10. Written Informed Consent and HIPAA authorization

11. Non-smoker for at least 6 months prior to screening and agrees not to smoke during the
study

12. Chest x-ray within the last six (6) months. If none, a chest x-ray is required before
randomization.

13. Willing and able to comply with the treatment schedule and procedures.

Exclusion Criteria:

1. Initiation of any new chronic therapy (e.g., ibuprofen, Pulmozyme®, hypertonic saline,
azithromycin, TOBI®, Cayston®) within 4 weeks prior to screening.

2. Use of antibiotics [oral, intravenous (iv), and/or inhaled] for acute respiratory
symptoms within 2 weeks prior to baseline.

3. Significant hemoptysis within 30 days prior to screening (≥5 mL of blood in one
coughing episode or >30 mL of blood in a 24 hour period)

4. History of colonization with nontuberculosis mycobacterium in sputum culture. The
investigator can be guided by the following suggested criteria for a subject to be
considered free of colonization:

- Two respiratory tract cultures negative for NTM in the last year, with no
subsequent positive cultures; and

- these 2 respiratory cultures must be separated by at least 3 months; and

- one of these two cultures has to have been obtained within the last 6 months

5. Cardiac (left heart) insufficiency (defined as LVEF <35%) at screening

6. Use of a nitric oxide donor agent such as nitroglycerin or drugs known to increase
methemoglobin such as lidocaine, prilocaine, benzocaine or dapsone at screening

7. Any of the following abnormal lab values at Screening:

- Hemoglobin < 10 g/dl

- Methemoglobn >3%

- Platelet count <100,000/mm3

- Prothrombin time international ratio (INR) > 1.5

- Abnormal liver function defined as any two of the following:

- ALT >3 x ULN

- AST >3 x ULN

- ALP > 3 x ULN

- GGT > 3 x ULN

- Abnormal liver function defined as:

- ALT >5 x ULN

- AST >5 x ULN

- Abnormal renal function defined as:

- Calculated Creatinine Clearance < 50 mL (as calculated by Cockcroft/Gault)

8. For women of child bearing potential:

- positive pregnancy test at screening or

- lactating or

- unwilling to practice a medically acceptable form of contraception from screening
to Day 36 (acceptable forms of contraception: abstinence, hormonal birth control,
intrauterine device, or barrier method plus a spermicidal agent)

9. Use of an investigational drug within 30 days prior to screening

10. Intravenous or oral steroids in the 14 days prior to screening

11. Current use of inhaled steroids >500 micrograms twice daily of Fluticasone or
equivalent in the 30 days prior to screening

12. Use of supplemental oxygen (daytime or nocturnal) in the 7 days prior to screening

13. Any condition that the Investigator believes would interfere with the intent of this
study or would make participation not in the best interest of the subject