ClinicalTrials.gg
TerminatedNCT03336580Updated Aug 20, 2020

A Study of PRX004 in Subjects With Amyloid Transthyretin (ATTR) Amyloidosis

A Phase 1 interventional study of PRX004 in Amyloidogenic Transthyretin (ATTR) Amyloidosis, sponsored by Prothena Biosciences Limited. Terminated at 7 sites in 4 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2020-08-20.

Sponsored by Prothena Biosciences Limited · Phase 1, Interventional, and Treatment

Why this study was terminated
Because of the impact of COVID-19 pandemic

From the registry’s dates

  • Primary completion was Jul 2020, 6 years 3 months ago, and no results have been posted to the registry.
Phase
Phase 1
Study type
Interventional
Enrollment
21
Allocation
Not applicable
Ages
18 Years and older
Sex
All
01

Study summary

A Phase 1, open-label study of intravenous (IV) PRX004 as a single agent in subjects with hereditary amyloid transthyretin (hATTR) amyloidosis. The study will consist of 3 phases and will enroll up to a total of 36 subjects. A 3+3 dose escalation component to determine the safety, tolerability, PK, PD, and MTD. An expansion component in anticipated PRX004 RP2D cohorts selected from the Dose Escalation Phase. An extended dosing component for eligible subjects from the Dose Escalation or Expansion phases.

Read the detailed description

This Phase 1, open-label consists of 3 phases. The Dose Escalation Phase is a 3+3 dose escalation component to determine the safety, tolerability, PK, PD, and MTD of IV PRX004 when given as a single agent in up to 36 evaluable subjects with hATTR amyloidosis. The Expansion Phase is an expansion component in anticipated PRX004 RP2D cohorts selected from the Dose Escalation Phase (this may occur in addition to cohorts in which additional subjects were added due to the observation of a dose-limiting [DLT] in the Escalation Phase). The Long-term Extension (LTE) Phase is an extended dosing component for eligible subjects from the Dose Escalation or Expansion phases.

The Dose Escalation Phase will follow a standard 3+3 design, in which cohorts of 3 to 6 subjects with hATTR amyloidosis will be enrolled at each dose level to receive IV PRX004 once every 28 days, based on scheduling from Month 1-Day 1 for up to 3 doses. Each subject will participate in only 1 dose escalation cohort. The starting dose of PRX004 will be 0.1 mg/kg.

Dose escalation will occur after the third evaluable subject in a cohort has completed the first 28 days following the first administration of PRX004. Up to 6 dose levels of PRX004 may be investigated (0.1, 0.3, 1, 3, 10, and 30 mg/kg) if tolerable. In the event the starting dose of 0.1 mg/kg is not tolerated, the dose escalationwill be halted and the study stopped.

Each subject will receive a maximum of 3 infusions of PRX004 in the Dose Escalation Phase. Subjects who complete the Month 3-Day 22 Visit in the Dose Escalation or Expansion phases may be eligible to receive up to 15 additional PRX004 infusions in the LTE Phase.

Each subject will receive a maximum of 3 infusions of PRX004 in the Dose Escalation Phase. Subjects who complete the Month 3-Day 22 Visit in the Dose Escalation or Expansion phases may be eligible to receive up to 15 additional PRX004 infusions in the LTE Phase.

Subjects who completed the EOS Visit in the Dose Escalation Phase prior to implementation of Protocol Amendment 2 may re-enter the study in the LTE Phase if they meet specific inclusion/exclusion criteria.

02

Conditions studied

  • Amyloidogenic Transthyretin (ATTR) Amyloidosis

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03

In context

Amyloidosis

290 studies on the registry are indexed under Amyloidosis; 92 are open to participants now.

This study's enrollment of 21 is below the median of 46 across 189 interventional studies indexed under Amyloidosis.

Browse Amyloidosis studies →

Lead sponsor

Prothena Biosciences Limited is the lead sponsor of 5 studies on the registry; none are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  1. Age ≥18 years
  2. Ability to understand and willingness to sign an form prior to initiation of any study procedures
  3. Diagnosis of amyloidosis determined by polarizing light microscopy of green birefringent material in Congo Red-stained tissue specimens; and confirmed diagnosis of ATTR amyloidosis by immunohistochemistry, mass spectrometry, documentation of an ATTR mutation by gene sequencing, or 99m technetium-3,3-diphosphono-1,2-propanodicarboxylic acid (99mTc-DPD) scans and/or technetium pyrophosphate (PYP) SPECT cardiac imaging. If scintigraphy is used for diagnosis then the grade must be 2 or greater, indicative of transthyretin amyloidosis-cardiomyopathy (ATTR-CM) (Gillmore, 2016)
  4. Known TTR mutation
  5. [Inclusion Criterion 5 removed in Amendment 2]
  6. Patients receiving concomitant tafamidis or diflunisal may enroll in the study, providing the dose has been stable for the last 6 months
  7. Performance Status (KPS) ≥60%
  8. Adequate organ function, including all of the following:

    1. Adequate bone marrow reserve, defined as the following: ≥1.0 × 109/L; count ≥100 × 109/L; ≥10 g/dL
    2. Hepatic: total ≤ 2 times the (× ULN), transaminases ( and/or alanine aminotransferase) ≤3 × ULN; alkaline phosphatase ≤5 × ULN
    3. Renal: estimated (eGFR) ≥45 mL/min/1.73 m2
  9. If currently receiving a diuretic, must have been on a stable dose for at least 4 weeks prior to the first dose of study drug
  10. Systolic blood pressure ≥90 mmHg and ≤180 mmHg
  11. Subjects with cardiomyopathy must have an NT-proBNP ≥650 pg/mL and ≤5000 pg/mL (ie, ≥76.9 pmol/L and ≤591 pmol/L) or evidence of septal wall thickening >1.2 cm on echocardiogram
  12. Must have a unless data are available from a previous one. The biopsy may be taken from any tissue or organ affected by ATTR amyloidosis (eg, skin, lip, abdominal fat pad, salivary gland), at the Investigator's discretion. Nerve biopsies are not required.
  13. Women of must have 2 negative pregnancy tests during Screening, the second within 24 hours prior to the first administration of study drug, and must agree to use highly effective physician-approved from Screening to 90 days following the last study drug administration
  14. Male subjects must be surgically sterile or must agree to use highly effective physician-approved contraception from Screening to 90 days following the last study drug administration
  15. Polyneuropathy Disability (PND) Score ≤IIIB
  16. Neuropathy Impairment Score (NIS) ≥5 and ≤130

Exclusion criteria

Exclusion Criteria:

  1. Amyloid light chain or other non-ATTR amyloidosis
  2. Any past history of or present abuse of alcohol, diabetes, B12 or folate deficiencies, diseases, hereditary disorders other than transthyretin (eg, Charcot-Marie-Tooth), uncontrolled hypothyroidism, or other etiologies for the peripheral neuropathy
  3. Received prior liver transplant
  4. Planned liver transplant during the study
  5. Modified (mBMI) ≤600 kg/m2 × g/L
  6. (NYHA) Functional Class III-IV (Appendix 2)
  7. ≤45%
  8. Uncontrolled symptomatic orthostatic hypotension
  9. Myocardial infarction, unstable or uncontrolled angina, severe uncontrolled ventricular arrhythmias, or electrocardiographic evidence of acute ischemia, within 6 months prior to the first dose of study drug
  10. Any history of sinus pauses on
  11. Sinus pauses >3 seconds in the day or sinus pauses >5 seconds at night during the 48-hour pre-dose cardiac monitoring (ie, prior to first dose of study drug)
  12. Arrhythmia requiring treatment diagnosed during the 48-hour pre-dose cardiac monitoring (ie, prior to first dose of study drug). Note: subject could be reconsidered for entry into the study if appropriate treatment is obtained
  13. Hospitalized for heart failure within the 12 weeks prior to the first dose of study drug
  14. Uncontrolled infection, or active with the exception of the following:

    • Adequately treated basal cell carcinoma, squamous cell carcinoma of the skin, or in situ cervical cancer
    • Low risk prostate cancer with Gleason score \<7 and prostate specific antigen \<10 mg/mL
    • Any other cancer from which the subject has been disease-free for ≥2 years
  15. Clinically significant pleural effusion per Investigator (e.g., presence of pleural effusion ≥30% in either hemithorax)
  16. History of Grade ≥3 -associated AEs or hypersensitivities to other monoclonal antibodies or the found in the PRX004 formulation
  17. Known infection or known or C virus carrier
  18. Women who are pregnant or breastfeeding
  19. Treatment with an agent within 30 days or 5 half-lives (whichever is longer) prior to Month 1-Day 1
  20. Any condition which could interfere with, or the treatment for which might interfere with, the conduct of the study or which would, in the opinion of the Medical Monitor or Investigator unacceptably increase the subject's risk by participating in the study
  21. Treatment with patisiran or inotersen within 90 days or 5 halflives (whichever is longer) prior to Month 1-Day 1
Terms in these criteria, in plain language(24)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

Karnofsky performance status (KPS)

A 0–100 scale of how well someone can carry out everyday activities. 100 is no complaints and no signs of illness; 70 is able to look after yourself but not to work or keep up normal activity; 50 is needing considerable help and frequent medical care.

Studies often ask for 60 or 70 and above. Your doctor gives the score.

Absolute neutrophil count (ANC)

The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.

It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.

Platelets

Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.

Hemoglobin (Hb)

The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).

Bilirubin

A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.

Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.

ULN (upper limit of normal)

The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.

“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.

ALT and AST (liver enzymes)

Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.

Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.

GFR and eGFR (kidney filtering)

GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².

Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.

Biopsy and archival tissue

A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.

Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.

Childbearing potential

Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).

Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.

Contraception

Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.

Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.

Autoimmune disease

A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.

Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.

BMI (body mass index)

Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.

What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.

NYHA class (heart failure)

The New York Heart Association’s four classes of how much heart failure limits physical activity.

I
No limits: ordinary activity causes no undue tiredness or breathlessness.
II
Slight limits: comfortable at rest, ordinary activity causes symptoms.
III
Marked limits: comfortable at rest, less than ordinary activity causes symptoms.
IV
Symptoms even at rest; any activity makes them worse.

Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.

LVEF (left ventricular ejection fraction)

The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.

Clinically significant

Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.

ECG (electrocardiogram)

A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.

Cancer (malignancy)

Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.

Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.

Hypersensitivity

An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.

Excipients

The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.

HIV

The human immunodeficiency virus, which weakens the immune system.

Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.

Hepatitis B tests

Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.

Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.

Investigational drug or device

A drug or device being studied in a clinical trial.

It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.

05

Study design

Phase
Phase 1
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrollment
21 participants (actual)

Study arms

  • Experimental
    PRX004

    Dose escalation in up to 6 dose levels Expansion of previously studied cohort(s) from Dose Escalation Extended dosing at RP2D

    Drug: PRX004

Interventions

  • DrugPRX004

    PRX004 (0.1, 0.3, 1, 3, 10, and 30 mg/kg) IV every 28 days PRX004 IV every 28 days at RP2D(s) PRX004 IV every 28 days at RP2D(s)

06

What researchers measure

Primary outcomes

  1. Maximum Tolerated Dose of PRX004

    Maximum Tolerated Dose of PRX004

    Time frame: 28 days

  2. Number of subjects with treatment-emergent adverse events and clinically significant changes in ECGs, echocardiograms, cardiac telemetry, vital signs, and laboratory evaluations

    Number of subjects with treatment-emergent adverse events and clinically significant changes in ECGs, echocardiograms, cardiac telemetry, vital signs, and laboratory evaluations

    Time frame: 3 months

Secondary outcomes

  1. PRX004 pharmacokinetic parameters - Cmin

    Minimum observed concentration (Cmin) of PRX004 in plasma

    Time frame: 3 months

  2. PRX004 pharmacokinetic parameters -Cmax

    Maximum observed concentration (Cmax) of PRX004 in plasma

    Time frame: 3 months

  3. PRX004 pharmacokinetic parameters - T1/2

    Terminal elimination half-life (T1/2) of PRX004 in plasma

    Time frame: 3 months

  4. PRX004 pharmacokinetic parameters -AUClast

    Area under the concentration-time curve from time zero to the last quantifiable concentration time-point (AUClast) of PRX004 in plasma

    Time frame: 3 months

  5. PRX004 pharmacokinetic parameters -AUCtau

    Area under the concentration-time curve over the dosing interval (AUCtau) of PRX004 in plasma

    Time frame: 3 months

  6. Immunogenicity indicators

    Immunogenicity indicators: Anti-drug antibodies (ADAs)

    Time frame: 3 months

07

Study locations

7 sites
  • Tufts Medical Center
    Boston, Massachusetts 02111, United States
  • Mayo Clinic Minnesota
    Rochester, Minnesota 55905, United States
  • Oregon Health and Science University
    Portland, Oregon 97239, United States
  • Penn Presbyterian Medical Center
    Philadelphia, Pennsylvania 19104, United States
  • Centro Hospitalar do Porto
    Porto, Portugal
  • Hospital Universitario Puerta de Hierro - Majadahonda
    Majadahonda, Madrid 28222, Spain
  • Umeå University Hospital
    Umeå, Sweden
08

References and documents

Publications

  • Capustin M, Frishman WH. Transthyretin Cardiac Amyloidosis and Novel Therapies to Treat This Not-so-rare Cause of Cardiomyopathy. Cardiol Rev. 2021 Sep-Oct 01;29(5):263-273. doi: 10.1097/CRD.0000000000000387. PubMed 34397539 ↗

Individual participant data

Plan to share: No

09

Timeline

Tracking since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reached

Ran from Apr 2018 to primary completion in Jul 2020, 27 months.

How these figures are worked out, and which studies are left out of them.

Registered
Oct 23, 2017
First posted
Nov 8, 2017
StartActual
Apr 5, 2018
Primary completionActual
Jul 23, 2020
CompletionActual
Jul 23, 2020
Last update
Aug 20, 2020
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on Aug 20, 2020, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT03336580
Lead sponsor
Prothena Biosciences Limited
Responsible party
Sponsor
First posted
Nov 8, 2017
Start date
Apr 5, 2018
Primary completion
Jul 23, 2020
Completion
Jul 23, 2020
Last update
Aug 20, 2020

Oversight

Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is terminated, as verified in Aug 2020. You cannot join it, but the record below documents what was studied.

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