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A Study of Encapsulated Cell Technology (ECT) Implant for Patients With Late Stage Retinitis Pigmentosa

A Phase II/III Study of Encapsulated Human NTC-201 Cell Implants Releasing Ciliary Neurotrophic Factor (CNTF) for Participants With Retinitis Pigmentosa Using Visual Acuity as the Primary Outcome

Status
Completed
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT00447993
Enrollment
67
Registered
2007-03-15
Start date
2007-01-08
Completion date
2009-05-26
Last updated
2024-08-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Retinitis Pigmentosa

Keywords

Retinitis Pigmentosa, eye disease, retinal disorder, CNTF

Brief summary

The purpose of this study is to look at the safety and effectiveness of CNTF implants on vision in persons with retinitis pigmentosa, Usher type II & III, and Choroideremia. This research is being done because there are no effective therapies for people with these retinal degenerations. They are genetic disorders that affect our ability to see at night, and later cause tunnel vision and loss of central vision. Retinal degenerations affect the retina, a light sensitive layer of cells in the back of the eye. Slowly over time, these cells die and cause permanent loss of vision. The implant is a small capsule that contains human retinal pigment epithelium cells. These cells have been given the ability to make CNTF and release it through the capsule membrane into the surrounding fluid. This study will look at the effect of the implant on vision loss by retinitis pigmentosa, Usher type II & III, and Choroideremia. In this study, two different CNTF dose levels will be used: a high dose and a low dose in one eye, as well as a sham (or placebo) surgery in the other eye.

Detailed description

This study will involve about 16 visits over 1½ years for specific tests of the participant's vision and health. These visits may include visual exams, blood draw for laboratory testing, brief medical history and exam, and occasionally a questionnaire (survey), in addition to the visit for the surgical procedures. The primary effectiveness outcome for this study will be a visual acuity score one year after the implant surgery. There will be about 13 centers participating in this study, and up to 60 people enrolled across the US. Each participant joining the study who has completed initial screening will then be scheduled to have a brief surgical procedure performed on each eye, one of which will include a very small cell-filled implant. Follow-up visits for repeat assessments will be required regularly to determine if the implant being tested is safe and effective for use to treat RP.

Interventions

COMBINATION_PRODUCTLow Dose NT-501

Low Dose NT-501 Implanted in study eye and fellow eye received sham surgery

COMBINATION_PRODUCTHigh Dose NT-501

High Dose NT-501 Implanted in study eye and fellow eye received sham surgery

Sponsors

Neurotech Pharmaceuticals
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
18 Years to 68 Years
Healthy volunteers
No

Inclusion criteria

1. Participant was older than 18, but less than 68 years of age. 2. Participant understood and signed the informed consent. If the participant's vision was impaired to the point where he/she could not read the informed consent document, the document would be read to the participant in its entirety. 3. Females of childbearing potential (women with last menses \<1 year prior to screening) agreed to use an effective form of birth control from study onset until they completed the 18-month study visit. 4. Participant was medically able to undergo ophthalmic surgery for the NT-501 device. 5. Participant's clinical diagnosis was consistent with retinal degeneration in the set of retinitis pigmentosa (RP) dystrophies characterized by the following features: 1. clinical evidence of progressive photoreceptor cell dysfunction and degeneration of the outer retina. 2. intraretinal bone-spicule'-like pigment observed in clinical examination (not necessarily applicable to choroideremia). 3. peripheral visual field constriction documented on standard testing. 4. symptomatic night blindness. 5. reduction of both rod and cone electroretinogram (ERG) responses. Individuals diagnosed with Retinitis Pigmentosa, Usher Syndrome Type 2 or Type 3 (without profound deafness or cochlear implant) or with Choroideremia (CHM) and who met the inclusion criteria were considered as potential candidates for this study. A maximum of 5 Usher Syndrome Type 2 or Type 3 and a maximum of 5 Choroideremia participants could be enrolled in this trial. 6. Each eye had a visual acuity score of at least 24 (20/320) and no more than 63 (20/63) letters. 7. Each eye had an ERG amplitude reduced below the 95% limit of normal (CI) per site by Full Field 28-32 Hz flicker.

Exclusion criteria

1. Participant was medically unable to comply with study procedures or follow-up visits. 2. Participant had glaucoma (defined as independent optic atrophy causing vision loss), irrespective of whether it was currently treated or untreated. 3. Participant had classic syndromic RP. 4. Participant had optic nerve atrophy beyond modest pallor, primary cone-rod dystrophy, unilateral bulls-eye maculopathy, cystoid maculopathy as judged by OCT reading center, or other retinal dystrophy. 5. Participant who had any of the following lens opacities: cortical opacity \> standard 3, posterior subcapsular opacity \> standard 3, or a nuclear opacity \> standard 3 as measured on the AREDS clinical lens grading system. 6. Participant had chronic requirement (e.g., \> or =4 weeks at a time) for ocular medications or has disease(s) that in the judgment of the examining physician were vision threatening, toxic to the lens, retina, or optic nerve or might affect the primary outcome. 7. Participant had a requirement of acyclovir and/or related products during study duration. To be eligible for this study, the participant must have discontinued use of these products prior to enrollment and must not continue with the products until after they had completed the study. 8. Participant had evidence of corneal opacification or lack of optical clarity. 9. Participant had undergone lens removal in the last 3 months, with or without intra-ocular lens implantation, or had undergone intra-ocular lens replacement within 6 months prior to enrollment. 10. Participant was receiving systemic steroids or other immunosuppressive medications. 11. Participant had undergone LASIK surgery or other refractive surgery for either eye in less than 6 months prior to screening. 12. Participant was currently participating in or had participated in any other clinical trial of a drug by ocular or systemic administration within the last 6 months. 13. Participant had previous exposure to an intra-ocular device or implant into the eye (excluding intra-ocular lens). 14. Participant had uveitis or other retinal inflammatory disease. 15. Participant was receiving oral or other insulin treatment for diabetes. 16. Participant who had a history of myocardial infarction within the last 12 months. 17. Participant was pregnant or lactating. 18. Participant was considered immunodeficient or had a known history of HIV. A laboratory test for HIV was performed, and a positive result was also an exclusion criterion. 19. Participant with a history of ocular herpes zoster. 20. Participant was on chemotherapy. 21. Participant had a history of malignancy, except study participants having cancer treated successfully ≥5 years prior to inclusion in the trial. 22. Participant with severe hearing disabilities in both ears. 23. Participant with diabetic retinopathy in either eye. 24. Participant had history of retinal detachment in either eye. 25. Participant had been diagnosed and treated for amblyopia as an infant. 26. Participant with a history of Pars Plana Vitrectomy.

Design outcomes

Primary

MeasureTime frameDescription
The Primary Outcome is the Change in Best-corrected Visual Acuity (BCVA) Using the Electronic Visual Acuity (EVA) Technology at Month 12.12 months post-implantThe primary efficacy endpoint was the proportion of patients demonstrating an improvement in best-corrected visual acuity (BCVA), defined as an increase of 10 letters or more at the 1-Year post-implant visit (pre-explant, if explant is completed). No response is defined as an improvement of \<10 letters.

Secondary

MeasureTime frameDescription
Number of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)From initial implant to 18 months post-implantThe key visits for efficacy assessments were Months 1, 3, 6, 12 and 18. At these time points, BCVA was measured 3 times and the mean outcome reported. The assessments were conducted by masked technicians. The change from baseline for BCVA was summarized by time. Response is defined as an improvement in visual acuity by an increase of 10 letters or more whereas no response is \<10 letters.

Countries

United States

Participant flow

Recruitment details

The total number of participant in the low dose group was 22 and the high dose group was 45 since each patient consented to treatment in one eye and sham treatment in the other eye.

Participants by arm

ArmCount
Low Dose Arm - Implant
NT-501 Low Dose Implant: encapsulated cell therapy that delivers ciliary neurotrophic factor to the retina
22
Low Dose Arm - Implant
NT-501 Low Dose Implant: encapsulated cell therapy that delivers ciliary neurotrophic factor to the retina
22
Low Dose Arm - Sham
Sham Implant in Fellow Eye (Low Dose Arm)
22
Low Dose Arm - Sham
Sham Implant in Fellow Eye (Low Dose Arm)
22
High Dose
NT-501 High Dose Implant: encapsulated cell therapy that delivers ciliary neurotrophic factor to the retina
45
High Dose
NT-501 High Dose Implant: encapsulated cell therapy that delivers ciliary neurotrophic factor to the retina
45
High Dose Arm - Sham
Sham Implant in Fellow Eye (High Dose Arm)
45
High Dose Arm - Sham
Sham Implant in Fellow Eye (High Dose Arm)
45
Total268

Withdrawals & dropouts

PeriodReasonFG000FG001FG002FG003
Overall StudyLost to Follow-up0022
Overall StudyWithdrawal by Subject0022

Baseline characteristics

CharacteristicLow Dose Arm - ImplantTotalHigh Dose Arm - ShamHigh DoseLow Dose Arm - Sham
Age, Continuous41.1 Years
STANDARD_DEVIATION 10.5
41.7 Years
STANDARD_DEVIATION 10.8
42.0 Years
STANDARD_DEVIATION 11
42.0 Years
STANDARD_DEVIATION 11
41.1 Years
STANDARD_DEVIATION 10.5
BCVA Letter Score45.5 Letters
STANDARD_DEVIATION 11.2
45.5 Letters
STANDARD_DEVIATION 10.3
46.7 Letters
STANDARD_DEVIATION 9.1
45.0 Letters
STANDARD_DEVIATION 10.4
44.8 Letters
STANDARD_DEVIATION 10.4
Ethnicity (NIH/OMB)
Hispanic or Latino
3 Participants10 Participants2 Participants2 Participants3 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
19 Participants124 Participants43 Participants43 Participants19 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants0 Participants0 Participants0 Participants0 Participants
Ocular History - Years Since RP Diagnosis24.66 Years
STANDARD_DEVIATION 9.55
22.52 Years
STANDARD_DEVIATION 12.17
21.50 Years
STANDARD_DEVIATION 13.21
21.50 Years
STANDARD_DEVIATION 13.21
24.66 Years
STANDARD_DEVIATION 9.55
Race (NIH/OMB)
American Indian or Alaska Native
1 Participants2 Participants0 Participants0 Participants1 Participants
Race (NIH/OMB)
Asian
2 Participants8 Participants2 Participants2 Participants2 Participants
Race (NIH/OMB)
Black or African American
1 Participants10 Participants4 Participants4 Participants1 Participants
Race (NIH/OMB)
More than one race
0 Participants0 Participants0 Participants0 Participants0 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants0 Participants0 Participants0 Participants0 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants0 Participants0 Participants0 Participants0 Participants
Race (NIH/OMB)
White
18 Participants114 Participants39 Participants39 Participants18 Participants
Sex: Female, Male
Female
8 Participants66 Participants25 Participants25 Participants8 Participants
Sex: Female, Male
Male
14 Participants68 Participants20 Participants20 Participants14 Participants
Type of Ocular History
Ocular Disease
22 Eyes134 Eyes45 Eyes45 Eyes22 Eyes
Type of Ocular History
Ocular Surgery
11 Eyes62 Eyes21 Eyes21 Eyes9 Eyes
Type of Ocular History
Ocular Treatment
2 Eyes8 Eyes2 Eyes2 Eyes2 Eyes

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
0 / 220 / 43
other
Total, other adverse events
22 / 2242 / 43
serious
Total, serious adverse events
1 / 220 / 22

Outcome results

Primary

The Primary Outcome is the Change in Best-corrected Visual Acuity (BCVA) Using the Electronic Visual Acuity (EVA) Technology at Month 12.

The primary efficacy endpoint was the proportion of patients demonstrating an improvement in best-corrected visual acuity (BCVA), defined as an increase of 10 letters or more at the 1-Year post-implant visit (pre-explant, if explant is completed). No response is defined as an improvement of \<10 letters.

Time frame: 12 months post-implant

Population: Results are based on participants who completed the 1-yr post implant visit/assessment.

ArmMeasureGroupValue (NUMBER)
Low Dose Arm - ImplantThe Primary Outcome is the Change in Best-corrected Visual Acuity (BCVA) Using the Electronic Visual Acuity (EVA) Technology at Month 12.Response (Greater than or equal to 10 letter improvement)1 participants
Low Dose Arm - ImplantThe Primary Outcome is the Change in Best-corrected Visual Acuity (BCVA) Using the Electronic Visual Acuity (EVA) Technology at Month 12.No Response20 participants
Low Dose Arm - ShamThe Primary Outcome is the Change in Best-corrected Visual Acuity (BCVA) Using the Electronic Visual Acuity (EVA) Technology at Month 12.No Response20 participants
Low Dose Arm - ShamThe Primary Outcome is the Change in Best-corrected Visual Acuity (BCVA) Using the Electronic Visual Acuity (EVA) Technology at Month 12.Response (Greater than or equal to 10 letter improvement)1 participants
High DoseThe Primary Outcome is the Change in Best-corrected Visual Acuity (BCVA) Using the Electronic Visual Acuity (EVA) Technology at Month 12.Response (Greater than or equal to 10 letter improvement)3 participants
High DoseThe Primary Outcome is the Change in Best-corrected Visual Acuity (BCVA) Using the Electronic Visual Acuity (EVA) Technology at Month 12.No Response39 participants
High Dose Arm - ShamThe Primary Outcome is the Change in Best-corrected Visual Acuity (BCVA) Using the Electronic Visual Acuity (EVA) Technology at Month 12.Response (Greater than or equal to 10 letter improvement)1 participants
High Dose Arm - ShamThe Primary Outcome is the Change in Best-corrected Visual Acuity (BCVA) Using the Electronic Visual Acuity (EVA) Technology at Month 12.No Response41 participants
Secondary

Number of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)

The key visits for efficacy assessments were Months 1, 3, 6, 12 and 18. At these time points, BCVA was measured 3 times and the mean outcome reported. The assessments were conducted by masked technicians. The change from baseline for BCVA was summarized by time. Response is defined as an improvement in visual acuity by an increase of 10 letters or more whereas no response is \<10 letters.

Time frame: From initial implant to 18 months post-implant

Population: Data set provides details for each timepoint based on number of patients who completed BCVA procedure at the each applicable visit.

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
Low Dose Arm - ImplantNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)12 months post-implant: No Response20 Participants
Low Dose Arm - ImplantNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)18 months post-implant: No Response19 Participants
Low Dose Arm - ImplantNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)1 month post-implant: Response1 Participants
Low Dose Arm - ImplantNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)3 months post-implant: Response2 Participants
Low Dose Arm - ImplantNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)3 months post-implant: No Response20 Participants
Low Dose Arm - ImplantNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)6 months post-implant: Response1 Participants
Low Dose Arm - ImplantNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)6 months post-implant: No Response20 Participants
Low Dose Arm - ImplantNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)18 months post-implant: Response0 Participants
Low Dose Arm - ImplantNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)12 months post-implant: Response1 Participants
Low Dose Arm - ImplantNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)1 month post-implant: No Response21 Participants
Low Dose Arm - ShamNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)3 months post-implant: Response1 Participants
Low Dose Arm - ShamNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)12 months post-implant: No Response20 Participants
Low Dose Arm - ShamNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)3 months post-implant: No Response21 Participants
Low Dose Arm - ShamNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)18 months post-implant: Response2 Participants
Low Dose Arm - ShamNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)6 months post-implant: No Response21 Participants
Low Dose Arm - ShamNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)1 month post-implant: No Response21 Participants
Low Dose Arm - ShamNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)1 month post-implant: Response1 Participants
Low Dose Arm - ShamNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)18 months post-implant: No Response17 Participants
Low Dose Arm - ShamNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)12 months post-implant: Response1 Participants
Low Dose Arm - ShamNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)6 months post-implant: Response0 Participants
High DoseNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)1 month post-implant: No Response40 Participants
High DoseNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)3 months post-implant: Response2 Participants
High DoseNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)6 months post-implant: No Response38 Participants
High DoseNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)3 months post-implant: No Response40 Participants
High DoseNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)6 months post-implant: Response4 Participants
High DoseNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)12 months post-implant: No Response39 Participants
High DoseNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)18 months post-implant: Response2 Participants
High DoseNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)1 month post-implant: Response3 Participants
High DoseNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)18 months post-implant: No Response30 Participants
High DoseNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)12 months post-implant: Response3 Participants
High Dose Arm - ShamNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)18 months post-implant: No Response32 Participants
High Dose Arm - ShamNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)3 months post-implant: Response0 Participants
High Dose Arm - ShamNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)1 month post-implant: Response1 Participants
High Dose Arm - ShamNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)1 month post-implant: No Response42 Participants
High Dose Arm - ShamNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)3 months post-implant: No Response42 Participants
High Dose Arm - ShamNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)6 months post-implant: Response2 Participants
High Dose Arm - ShamNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)6 months post-implant: No Response40 Participants
High Dose Arm - ShamNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)12 months post-implant: Response1 Participants
High Dose Arm - ShamNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)18 months post-implant: Response0 Participants
High Dose Arm - ShamNumber of Participants With and Without Best Corrected Visual Acuity Response Over the 18-month Follow-up Period (Months 1, 3, 6, 12 and 18)12 months post-implant: No Response41 Participants

Source: ClinicalTrials.gov · Data processed: Mar 25, 2026