Prion DiseasePhase 1/2NCT06153966
PrProfile: A Study to Assess the Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of ION717
A Phase 1/2 study testing ION717 in people with Prion Disease, run by Ionis Pharmaceuticals, Inc. at 13 sites in 9 countries.
Trial summary
The purpose of this study is to evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics of intrathecal (IT) delivery of ION717. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Prion Disease
- What is being tested?
- ION717
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 85 participants
- Where
- 13 sitesin 9 countries
- Study dates
- 4 Jan 2024to Aug 2030
- Phase
- Phase 1/2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- A confirmed diagnosis of probable or definite prion disease.
- Early-stage prion disease at the time of Screening.
- Willing to meet all study requirements, including travel to Study Center, procedures, measurements and visits.
- Patients must have a caregiver who is ≥ 18 years old and who is able and willing to facilitate the patient's involvement, to the best of their ability, for the duration of the trial; caregivers must also be able and willing to provide information about themselves and the patient for the duration of the trial.
- Aged ≥ 18 at the time of informed consent.
Who cannot join
- Clinically significant abnormalities in medical history, laboratory tests or physical examination that would render a patient unsuitable for inclusion.
- Any contraindication or unwillingness to undergo an MRI.
- Obstructive hydrocephalus, presence of a functional ventriculoperitoneal shunt for the drainage of cerebrospinal fluid (CSF) or an implanted central nervous system (CNS) catheter.
- Known brain or spinal disease that would interfere with the LP process, CSF circulation or safety assessment.
- Have any other condition, which, in the opinion of the Investigator would make the patient unsuitable for inclusion or could interfere with the patient participating in or completing the study.
Trial locations and contacts
13 sites in 9 countries.
13 sites in 9 countries
United States3 sites
Massachusetts General Hospital
Boston, Massachusetts, 02114
University Hospitals Cleveland Medical Center
Cleveland, Ohio, 44106
NYU Langone Health
New York, New York, 10016
Japan3 sites
Mihara Memorial Hospital
Gunma, Isesaki-shi, 372-0006
National Center of Neurology and Psychiatry
Tokyo, Kodaira-shi, 187-8551
Neuromuscular Center Yoshimizu Hospital
Yamaguchi, Shimonoseki-shi, 751-0826
About this study
Official title: A Phase 1/2a Study to Evaluate the Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of Intrathecally Administered ION717 in Patients With Prion Disease
The purpose of this study is to evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics of intrathecal (IT) delivery of ION717.
Read the detailed description
This is a first-in-human, multi-center study in participants with prion disease. The study will consist of a screening period of up to 6 weeks, a 30-week treatment period, a 142-week open-label extension period and a 32-week post-treatment period. Multiple dose levels will be tested.
The trial consists of three Regimens. Participants in Regimens 1 and 2 received multiple doses of study drug (ION717 and placebo) during the 30-week double-blind treatment period; the order of doses (i.e. whether a given dose was ION717 or placebo) was blinded. Regimen 3 is open label.
- Conditions
- Prion Disease
- Being tested
- ION717, Placebo
- Medical subject headings
- Prion Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ION717Drug
ION717 will be administered by IT injection.
PlaceboDrug
Placebo-matching ION717 will be administered by IT injection.
| Study group | Role | What they receive |
|---|---|---|
| ION717 + Placebo, Regimen 1 | Experimental | Participants will receive multiple doses of study drug (ION717 and placebo) during the 30-week treatment period; the order of doses is blinded. Participants will then receive multiple doses of ION717 during the 142-week open-label extension period. Receives: Drug: ION717; Drug: Placebo |
| ION717 + Placebo, Regimen 2 | Experimental | Participants will receive multiple doses of study drug (ION717 and placebo) during the 30-week treatment period; the order of doses is blinded. Participants will then receive multiple doses of ION717 during the 142-week open-label extension period. Receives: Drug: ION717; Drug: Placebo |
| ION717, Regimen 3 | Experimental | Participants will receive multiple doses of ION717 during the 30-week treatment period and the 142-week open-label extension period. Receives: Drug: ION717 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Incidence of treatment-emergent adverse events.
Measured: Baseline up to Week 33
Secondary outcomes (6)
Maximum Observed Plasma Concentration (Cmax) of ION717
Measured: on Day 1 and Week 9
Area Under the Plasma Concentration-time Curve (AUC) of ION717
Measured: on Day 1 and Week 9
Half-life (t1/2λz) of ION717 in Plasma
Measured: on Day 1 and Week 9
Cerebrospinal fluid (CSF) Concentration of ION717
Measured: Pre-dose and at multiple points post-dose up to Week 33
Amount of ION717 Excreted in Urine
Measured: Post-dose on Day 1
Percent Change from Baseline in Prion Protein (PrP) Concentration in CSF
Measured: Pre-dose and at multiple points post-dose up to Week 33
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Dec 2023
- Study start4 Jan 2024
- Primary completionApr 2027 (estimated)
- Study completionAug 2030 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Prion DiseaseStudies of the same condition, open and under way.
- More trials run by Ionis Pharmaceuticals, Inc.The sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1/2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 85 participants (actual)
Sponsor and investigators
- Lead sponsor
- Ionis Pharmaceuticals, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06153966
- Sponsor's protocol ID
- ION717-CS2
- Other IDs
- 2023-503355-98, 2023
- Status last verified
- Sep 2026
- First submitted
- 21 Nov 2023
- Last updated
- 18 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: Ionis may share anonymized individual participant data, aggregated clinical data, and other types of data that support the results in this study. Data requests from qualified researchers will be considered once all three of the following criteria are met: (1) 12 months from marketing approval of the study drug in both the United States and European Union; (2) 18 months from conclusion of the study; and (3) 6 months from publication of study article. Access would be via a secure environment and is contingent upon approval of a research proposal and entry into an appropriate data use agreement. Requests to access data can be submitted via the website https://vivli.org/ourmember/ionis/.
Study at a glance
From the registry record, last updated by the sponsor on 18 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 1/2a Study to Evaluate the Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of Intrathecally Administered ION717 in Patients With Prion Disease
- ClinicalTrials.gov ID
- NCT06153966
- Acronym / sponsor ID
- ION717-CS2
- Conditions
- Prion Disease
- Phase
- Phase 1/2
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 85 participants (actual)
- Lead sponsor
- Ionis Pharmaceuticals, Inc.Industry (pharma, biotech, devices)
- Study start
- 4 Jan 2024 (actual)
- Primary completion
- Apr 2027 (estimated)
- Study completion
- Aug 2030 (estimated)
- First posted
- 1 Dec 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this study is to evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics of intrathecal (IT) delivery of ION717.
Detailed description
This is a first-in-human, multi-center study in participants with prion disease. The study will consist of a screening period of up to 6 weeks, a 30-week treatment period, a 142-week open-label extension period and a 32-week post-treatment period. Multiple dose levels will be tested.
The trial consists of three Regimens. Participants in Regimens 1 and 2 received multiple doses of study drug (ION717 and placebo) during the 30-week double-blind treatment period; the order of doses (i.e. whether a given dose was ION717 or placebo) was blinded. Regimen 3 is open label.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| ION717 + Placebo, Regimen 1 | Experimental | Drug: ION717, Drug: PlaceboParticipants will receive multiple doses of study drug (ION717 and placebo) during the 30-week treatment period; the order of doses is blinded. Participants will then receive multiple doses of ION717 during the 142-week open-label extension period. |
| ION717 + Placebo, Regimen 2 | Experimental | Drug: ION717, Drug: PlaceboParticipants will receive multiple doses of study drug (ION717 and placebo) during the 30-week treatment period; the order of doses is blinded. Participants will then receive multiple doses of ION717 during the 142-week open-label extension period. |
| ION717, Regimen 3 | Experimental | Drug: ION717Participants will receive multiple doses of ION717 during the 30-week treatment period and the 142-week open-label extension period. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- A confirmed diagnosis of probable or definite prion disease.
- Early-stage prion disease at the time of Screening.
- Willing to meet all study requirements, including travel to Study Center, procedures, measurements and visits.
- Patients must have a caregiver who is ≥ 18 years old and who is able and willing to facilitate the patient's involvement, to the best of their ability, for the duration of the trial; caregivers must also be able and willing to provide information about themselves and the patient for the duration of the trial.
- Aged ≥ 18 at the time of informed consent.
Key exclusion criteria (5 listed)
- Clinically significant abnormalities in medical history, laboratory tests or physical examination that would render a patient unsuitable for inclusion.
- Any contraindication or unwillingness to undergo an MRI.
- Obstructive hydrocephalus, presence of a functional ventriculoperitoneal shunt for the drainage of cerebrospinal fluid (CSF) or an implanted central nervous system (CNS) catheter.
- Known brain or spinal disease that would interfere with the LP process, CSF circulation or safety assessment.
- Have any other condition, which, in the opinion of the Investigator would make the patient unsuitable for inclusion or could interfere with the patient participating in or completing the study.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| ION717ION717 will be administered by IT injection. | Drug | ION717 + Placebo, Regimen 1, ION717 + Placebo, Regimen 2, ION717, Regimen 3 |
| PlaceboPlacebo-matching ION717 will be administered by IT injection. | Drug | ION717 + Placebo, Regimen 1, ION717 + Placebo, Regimen 2 |
Primary outcome
Incidence of treatment-emergent adverse events.
Time frame: Baseline up to Week 33
6 secondary outcomes
Maximum Observed Plasma Concentration (Cmax) of ION717
Time frame: on Day 1 and Week 9
Area Under the Plasma Concentration-time Curve (AUC) of ION717
Time frame: on Day 1 and Week 9
Half-life (t1/2λz) of ION717 in Plasma
Time frame: on Day 1 and Week 9
Cerebrospinal fluid (CSF) Concentration of ION717
Time frame: Pre-dose and at multiple points post-dose up to Week 33
Amount of ION717 Excreted in Urine
Time frame: Post-dose on Day 1
Percent Change from Baseline in Prion Protein (PrP) Concentration in CSF
Time frame: Pre-dose and at multiple points post-dose up to Week 33
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 18 Sep 2026.
- Individual participant dataSharing planned: Yes. Ionis may share anonymized individual participant data, aggregated clinical data, and other types of data that support the results in this study. Data requests from qualified researchers will be considered once all three of the following criteria are met: (1) 12 months from marketing approval of the study drug in both the United States and European Union; (2) 18 months from conclusion of the study; and (3) 6 months from publication of study article. Access would be via a secure environment and is contingent upon approval of a research proposal and entry into an appropriate data use agreement. Requests to access data can be submitted via the website https://vivli.org/ourmember/ionis/.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
13 sites in 9 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1/2 study testing ION717 in people with Prion Disease, run by Ionis Pharmaceuticals, Inc. at 13 sites in 9 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 18 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 13 sites in United States, Japan, Australia, Canada, France and 4 more countries. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this combined phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Incidence of treatment-emergent adverse events. (time frame: Baseline up to Week 33). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 18 Sep 2026; AzTrials last refreshed its copy on 7 Nov 2026.