A Study of the Dosing, Efficacy, and Safety of Oral Cysteamine in Adult Patients With Cystic Fibrosis Exacerbations

This is a multicenter, double-blind, randomized, placebo-controlled, 6-arm study to
investigate the optimal dose regimen, efficacy, and safety of cysteamine in the treatment of
adult patients with CF who are experiencing an exacerbation of CF-associated lung disease.
Patients will be screened for the study and eligible patients will be randomized to receive
either cysteamine or placebo as add-on therapy to their standard of care treatment for
CF-associated lung disease.

Inclusion Criteria:

1. CF-associated lung disease with documented history of chronic infection with
Gram-negative organism(s)

2. Established patient of the Principal Investigator's CF Multi Disciplinary Team (MDT)

3. Age ≥18 years

4. Weight >40 kg

5. FEV1 >30% of predicted within the 6 months prior to study exacerbation

6. At the baseline visit: experiencing a new exacerbation of CF-associated lung disease
(based on Investigator assessment of ≥4 symptoms present on the Fuchs' criteria)
requiring treatment that includes an aminoglycoside antibiotic

7. Females of childbearing potential will be included if they are either sexually
inactive (sexually abstinent for 14 days prior to the first study drug dose continuing
through 28 days after the last study drug dose, or using one of the following highly
effective contraceptive (i.e. results in <1% failure rate when used consistently and
correctly) methods in this trial:

1. intrauterine device (IUD);

2. surgical sterilization of the partner (vasectomy for 6 months minimum);

3. combined (estrogen or progestogen containing) hormonal contraception associated
with the inhibition of ovulation (either oral, intravaginal, or transdermal);

4. progestogen only hormonal contraception associated with the inhibition of
ovulation (either oral, injectable, or implantable);

5. intrauterine hormone releasing system (IUS);

6. bilateral tubal occlusion.

8. Females of childbearing potential agree to remain sexually inactive or to keep the
same birth control method for at least 28 days following the last dose.

9. A female of non-childbearing potential must have undergone one of the following
sterilization procedures at least 6 months prior to the first study drug dose:

1. hysteroscopic sterilization;

2. bilateral tubal ligation or bilateral salpingectomy;

3. hysterectomy;

4. bilateral oophorectomy; or be postmenopausal with amenorrhea for at least 1 year
prior to the first study drug dose and follicle stimulating hormone (FSH) serum
levels consistent with postmenopausal status.

10. A non-vasectomized male subject agrees to use a condom with spermicide or abstain from
sexual intercourse during the study until 90 days beyond the last dose of study
medication and the female partner agrees to comply with inclusion 7 or 9. For a
vasectomized male who has had his vasectomy 6 months or more prior to study start, it
is required that they use a condom during sexual intercourse. A male who has been
vasectomized less than 6 months prior to study start must follow the same restrictions
as a non-vasectomized male.

11. If male, agrees not to donate sperm from the first study drug dose until 90 days after
dosing.

12. Willing and able to comply with all protocol requirements and procedures, including
induction of sputum, if necessary

13. Willing and able to provide signed and dated informed consent

Exclusion Criteria:

1. Hypersensitive to cysteamine or to any of the excipients

2. Hypersensitive to penicillamine

3. Transplant recipient

4. Participation in any other interventional clinical research study (participation in
observational studies is not exclusionary) within 30 days of Baseline (Day 0), and any
planned participation in an interventional clinical research study for the duration of
this study

5. If female, pregnancy, planned pregnancy, or breast-feeding

6. Any other significant disease/disorder which, in the Investigator's opinion, either
puts the patient at risk due to study participation, or may influence the results of
the study or the patient's ability to participate in the study