This is a Phase 3 open-label, multicenter, randomized, active-controlled study designed to
compare the efficacy and safety and tolerability of P1101 compared with ANA after 12 months
of treatment as second-line therapy for subjects with ET who have had a suboptimal or failed
response to HU.
PharmaEssentia Corporation is developing a pegylated (PEG) IFN-α product, P1101, for the
treatment of ET.
Available clinical data and experience with P1101 in PV shows that the compound, with proper
dose modifications, is effective in controlling disease in a significant proportion of
subjects with ET. Further, its increased serum half-life presents distinct advantages for ET
treatment over that of standard IFN-α and other available PEG IFN-α therapy. This pivotal
Phase 3 study will establish the efficacy and safety of P1101 in ET subjects.
The enrolled subjects will be randomized into two arms, the test arm is P1101, the control
arm is ANA. The overall duration for each eligible patient is 14 months, including screening
(1 month), treatment (12 months) and follow-up (1 month) period. Efficacy evaluations, safety
assessments, and PK and immunogenicity evaluations of P1101 will be performed.
Evaluation of efficacy will include clinical laboratory assessments, allelic burden
measurements of CALR, JAK-2, and MPL, spleen size measurements, bone marrow sampling,
EQ-5D-3L, and MPN-SAF TSS completion.
Evaluation of safety will include assessing vital signs, clinical safety laboratory tests,
physical examinations, ECG evaluation, heart ECHO, lung X-ray, ECOG performance status,
ocular examination, and AEs.
Inclusion Criteria:
1. Male or female subjects ≥18 years old
2. Subjects diagnosed with high-risk ET (either older than 60 years and JAK2V617-positive
at screening, or having disease-related thrombosis or hemorrhage in the past),
diagnosed according to the World Health Organization (WHO) 2016 criteria
3. Subjects have received prior HU for ET, while the washout between the last dose of HU
and the screening visit should not be shorter than 14 days
4. Interferon treatment-naïve
5. Documented resistance/intolerance to prior HU for ET, as defined by modified ELN
criteria (Barosi, et al, 2007), whereby at least one of the following criteria is met:
Platelet count >600 x 109/L at ≥2 g/day (or ≥2.5 g/day if subject body weight >80 kg)
or maximally tolerated dose if <2 g/day after at least 3 months of HU, or Platelet
count >400 x 109/L and WBC count <2.5 x 109/L at any dose and any duration of HU, or
Platelet count >400 x 109/L and hemoglobin (HGB) <10 g/dL at any dose and any duration
of HU, or Presence of HU-related toxicities at any dose and any duration of therapy
(e.g., leg ulcers, mucocutaneous manifestations, pneumonitis, or HU-related fever)
6. Platelets >450 x 109/L at screening
7. WBC >10 x 109/L at screening
8. HGB ≥11 g/dL at screening for males and 10 g/dL at screening for females
9. Neutrophil count ≥1.0 x 109/L at screening
10. Adequate hepatic function defined as bilirubin ≤1.5 x upper limit normal (ULN),
prothrombin time (PT) (international normalized ratio, INR) ≤1.5 x ULN, albumin >3.5
g/dL, alanine aminotransferase ≤2.0 x ULN, aspartate aminotransferase ≤2.0 x ULN at
screening
11. Creatinine clearance ≥40 mL/min (by Cockcroft-Gault equation)
12. Males and females of childbearing potential, as well as all women <2 years after the
onset of menopause, must agree to use an acceptable form of birth control until 28
days following the last dose of the study drug, and females must agree to not
breastfeed during the study
13. Written informed consent obtained from the subject and ability for the subject to
comply with the requirements of the study
Exclusion Criteria:
1. Any subject requiring a legally authorized representative
2. Any contraindications or hypersensitivity to IFN-α or ANA and their excipients
3. Known risk factors for QT-prolongation (e.g., congenital long QT, known history of
acquired QT-prolongations). Medications that can prolong QTc and induce hypokalemia
will not be allowed in the study.
4. Co-morbidity with severe or serious condition that, in the Investigator's opinion,
would jeopardize the safety of the subject or their compliance with the protocol,
including significant cardiac disease (including New York Heart Association Class
III-IV congestive heart failure and clinically significant arrhythmias) and pulmonary
hypertension
5. History of major organ transplantation
6. Pregnant or lactating females
7. Subjects with any other significant medical conditions that, in the opinion of the
Investigator, would compromise the results of the study or may impair compliance with
the requirements of the protocol, including but not limited to:
1. Documented autoimmune disease at screening or in the history (e.g., thyroid
dysfunction, hepatitis, idiopathic thrombocytopenic purpura, scleroderma,
psoriasis, or any arthritis of autoimmune origin)
2. Clinically relevant pulmonary infiltrates, pneumonia, and pneumonitis at
screening that, in the Investigator's opinion, would jeopardize the safety of the
subject or their compliance with the protocol
3. Infections with systemic manifestations (e.g., bacterial, fungal, or human
immunodeficiency virus [HIV], except hepatitis B [HBV] and/or hepatitis C [HCV],
at screening)
4. Evidence of severe retinopathy (e.g., cytomegalovirus retinitis, macular
degeneration) or clinically relevant ophthalmological disorder (due to diabetes
mellitus or hypertension)
5. History or presence of clinically relevant depression, or previous suicide
attempts or at any risk of suicide at screening, in the judgement of the
Investigator
6. History or presence of clinically significant neurodegenerative diseases
7. History of any malignancy within 5 years (except Stage 0 chronic lymphocytic
leukemia, basal cell, squamous cell, and superficial melanoma)
8. History of alcohol or drug abuse within the last year
9. History or evidence of any other MPN
8. Use of any investigational drug <4 weeks prior to the first dose of study drug or not
recovered from effects of prior administration of any investigational agent
9. Subjects with documented ANA resistance or intolerance (see Appendix 8 for
definition).