Coversin in PNH in Patients With Resistance to Eculizumab Due to Complement C5 Polymorphisms

Coversin, a small protein complement C5 inhibitor which prevents the cleavage of C5 by C5
convertase into C5a and C5b, will be used in an open label, non-comparative clinical trial in
patients with PNH and proven resistance to eculizumab due to C5 polymorphisms. Patients will
be treated with Coversin by daily subcutaneous injection for 6 months in order to determine
the safety and efficacy of the drug in these circumstances. If satisfactory control of the
PNH is achieved, and at the discretion of the Principal Investigator (PI), patients will have
the option of remaining on Coversin and being entered into the long term follow-up study.

Inclusion Criteria:

1. Patients with known PNH.

2. Aged 18 and above. No upper age limit.

3. Lactate dehydrogenase (LDH) ≥1.5 upper limit of normal.

4. Must agree to use two methods of contraception that are ≥99% effective in preventing
pregnancy.

5. Resistance to eculizumab (Soliris®).

6. Voluntary written informed consent.

7. Willing to self-inject Coversin daily.

8. Willing to receive appropriate prophylaxis against Neisseria infection.

9. Willing to avoid prohibited medications for duration of study.

Exclusion Criteria:

1. Subjects with body weight <50 kg (110 lb) or >100 kg (220 lb).

2. Pregnancy or breast feeding (females).

3. Known allergy to ticks or severe reaction to arthropod venom (e.g. bee or wasp venom).

4. Unresolved Neisseria meningitidis infection.

5. Patients who have not received adequate immunization against Neisseria meningitides.

6. Impaired hepatic function.

7. Patients with impaired renal function.

8. Failure to satisfy the Principal Investigator (PI) of fitness to participate for any
other reason.