Trial · NCT00447980

A Study of Encapsulated Cell Technology (ECT) Implant for Participants With Early Stage Retinitis Pigmentosa

NCT00447980, Phase 2, Completed, Neurotech Pharmaceuticals; results first posted 2025-05-01

3 sourcestrials-2026-11-12-0.5.0

Cite this record

ConductScience Library. A Study of Encapsulated Cell Technology (ECT) Implant for Participants With Early Stage Retinitis Pigmentosa. Trials, record NCT00447980. Release trials-2026-11-12-0.5.0, 12 Nov 2026. https://conductscience.org/library/trials/NCT00447980

On this page

Trial

As registered on ClinicalTrials.gov, in the graph's capture of the registry.

Title: A Study of Encapsulated Cell Technology (ECT) Implant for Participants With Early Stage Retinitis Pigmentosa
NCT number: NCT00447980
Status: Completed
Phases: Phase 2
Enrollment: 73 participants, actual
Lead sponsor: Neurotech Pharmaceuticals
Conditions: Retinitis Pigmentosa
Interventions: NT-501, NT-501
First posted: 2007-03-15
Last updated: 2025-05-01
Results first posted: 2025-05-01

Source ClinicalTrials.gov

Registered outcomes3

Each outcome the trial registered, primary first, in ClinicalTrials.gov's words.

List	Outcome	Time frame	Description
Primary	Change in Humphrey Visual Fields - Total Sensitivity	12 months	The primary efficacy endpoint was the change in Humphrey VFS from baseline to month 12 (Visit 10) as determined by the HVF 30-2 test, comprised of 76 points. The measure was the sum of actual thresholds for all 76 locations.
Secondary	Change in Mean Humphrey Visual Fields Sensitivity	Baseline compared to 6, 12, 18, 24 and 30 months
Secondary	Mean Humphrey Visual Fields Sensitivity	Baseline compared to 6, 12, 18, 24 and 30 months	Change in Humphrey Visual Field Sensitivity over time

Source ClinicalTrials.gov

Outcomes3

Each outcome the trial posted results for, in ClinicalTrials.gov's words.

Type	Outcome	Time frame	Population	Units	Measured as
PRIMARY	Change in Humphrey Visual Fields - Total Sensitivity	12 months	MITT Population excluding 1 participant from the high dose arm who did not complete any visits subsequent to surgery.	dB	MEAN
SECONDARY	Change in Mean Humphrey Visual Fields Sensitivity	Baseline compared to 6, 12, 18, 24 and 30 months	MITT Population excluding 1 participant from the high dose arm who did not complete any visits subsequent to surgery.	dB	MEAN
SECONDARY	Mean Humphrey Visual Fields Sensitivity	Baseline compared to 6, 12, 18, 24 and 30 months	MITT Population	dB	MEAN

Source ClinicalTrials.gov

Results by group56

Each measurement the trial posted, group by group, in the words and numbers it posted.

Outcome	Group	Category	Value	Spread	Units
Change in Humphrey Visual Fields - Total Sensitivity	Low Dose - Implant		1.4	Standard Deviation 174.58	dB
Change in Humphrey Visual Fields - Total Sensitivity	Low Dose - Sham		16.8	Standard Deviation 165.41	dB
Change in Humphrey Visual Fields - Total Sensitivity	High Dose - Implant		-164.8	Standard Deviation 115.02	dB
Change in Humphrey Visual Fields - Total Sensitivity	High Dose - Sham		-66.7	Standard Deviation 103.23	dB
Change in Mean Humphrey Visual Fields Sensitivity	Low Dose - Implant	6 Months - Change from BL	-1.21	Standard Deviation 140.09	dB
Change in Mean Humphrey Visual Fields Sensitivity	Low Dose - Sham	6 Months - Change from BL	25.80	Standard Deviation 128.34	dB
Change in Mean Humphrey Visual Fields Sensitivity	High Dose - Implant	6 Months - Change from BL	-135.23	Standard Deviation 107.86	dB
Change in Mean Humphrey Visual Fields Sensitivity	High Dose - Sham	6 Months - Change from BL	-42.99	Standard Deviation 82.85	dB
Change in Mean Humphrey Visual Fields Sensitivity	Low Dose - Implant	12 Months - Change from BL	1.35	Standard Deviation 174.58	dB
Change in Mean Humphrey Visual Fields Sensitivity	Low Dose - Sham	12 Months - Change from BL	16.75	Standard Deviation 165.41	dB

1 to 10 of 56Source ClinicalTrials.gov

See all 56 results by group

Participant flow16

How many started, completed or left each group, period by period.

Period	Milestone	Group	Participants	Units counted
Overall Study	STARTED	Participants That Received Low Dose NT-501 Implant Surgery and Sham Surgery in Fellow Eye	23	23
Overall Study	STARTED	Sham Treatment in Fellow Eye for Low Dose Arm	23	23
Overall Study	STARTED	Participants That Received High Dose NT-501 Implant Surgery and Sham Surgery in Fellow Eye	50	50
Overall Study	STARTED	Sham Treatment in Fellow Eye for High Dose Implant Arm	50	50
Overall Study	NT-501 Surgery Completed	Participants That Received Low Dose NT-501 Implant Surgery and Sham Surgery in Fellow Eye	20	20
Overall Study	NT-501 Surgery Completed	Sham Treatment in Fellow Eye for Low Dose Arm	20	20
Overall Study	NT-501 Surgery Completed	Participants That Received High Dose NT-501 Implant Surgery and Sham Surgery in Fellow Eye	48	48
Overall Study	NT-501 Surgery Completed	Sham Treatment in Fellow Eye for High Dose Implant Arm	48	48
Overall Study	COMPLETED	Participants That Received Low Dose NT-501 Implant Surgery and Sham Surgery in Fellow Eye	18	18
Overall Study	COMPLETED	Sham Treatment in Fellow Eye for Low Dose Arm	18	18

1 to 10 of 16Source ClinicalTrials.gov

See all 16 participant flow

Adverse events104

Each adverse event the trial posted, group by group: the participants affected out of those at risk.

Type	Event	Organ system	Group	Affected	At risk	Events
other	Anterior Chamber Cell	Eye disorders	Low Dose	7	20	7
other	Anterior Chamber Cell	Eye disorders	High Dose	9	48	9
other	Anterior Chamber Flare	Eye disorders	Low Dose	5	20	5
other	Anterior Chamber Flare	Eye disorders	High Dose	9	48	9
other	Asthenopia	Eye disorders	Low Dose	2	20	2
other	Asthenopia	Eye disorders	High Dose	1	48	1
other	Cataract Subcapsular	Eye disorders	Low Dose	1	20	1
other	Cataract Subcapsular	Eye disorders	High Dose	2	48	2
other	Conjunctival Haemorrhage	Eye disorders	Low Dose	17	20	17
other	Conjunctival Haemorrhage	Eye disorders	High Dose	38	48	38

1 to 10 of 104Source ClinicalTrials.gov

See all 104 adverse events

Adverse event totals6

The totals the trial posted for each group.

Total	Group	Affected	At risk
Total, all-cause mortality	Low Dose	0	20
Total, all-cause mortality	High Dose	0	48
Total, other adverse events	Low Dose	20	20
Total, other adverse events	High Dose	48	48
Total, serious adverse events	Low Dose	1	20
Total, serious adverse events	High Dose	4	48

Source ClinicalTrials.gov

Papers3

The papers the trial lists on ClinicalTrials.gov.

PMID	Listed as	Source
21087953	DERIVED	PubMed
23049090	DERIVED	PubMed
23668681	DERIVED	PubMed

Grants0

The grants NIH RePORTER links to the trial, newest funded first: NIH's, and some of AHRQ's, CDC's, FDA's and VA's. Each shows its title, principal investigators, organization and funder in its newest year.

None in this release.

Trial comparisons2

Comparisons of the trial's two groups, calculated by ConductScience from the counts it posted.

Comparison	Source
Low Dose vs High Dose: deaths from any cause	Trial comparisons
Low Dose vs High Dose: serious adverse events	Trial comparisons

Tests0

The ConductCognition tests this trial's registered outcomes name, as ScienceGraph matched them in trial-tests-2026-11-12-0.2.1.

None in this release.

Data dates

The day each source was copied for this release.

ClinicalTrials.gov: 2026-11-12; ClinicalTrials.gov
Results, from AACT: 2026-03-23; AACT
NIH grant links: 2026-11-13; NIH RePORTER

Sources 3

ClinicalTrials.gov's posted results, through CTTI's AACTFreely available. Acknowledgement requested
ClinicalTrials.govNo license stated
NIH RePORTER's clinical studies and project filesPublic domain

Each source's terms

ClinicalTrials.gov's posted results, through CTTI's AACTClinicalTrials.gov data via Aggregate Analysis of ClinicalTrials.gov (AACT), CTTI. CTTI makes its materials freely available and requests acknowledgement. https://aact.ctti-clinicaltrials.org/documentation/299
ClinicalTrials.govnone stated
NIH RePORTER's clinical studies and project filesPublic domain (NIH RePORTER)

ClinicalTrials.gov's data carry an international copyright outside the United States: https://clinicaltrials.gov/about-site/terms-conditions.

For software

Read this trial from software.

The record and each of its lists are JSON, twenty rows a page. No key.

GET https://conductscience.org/api/trials/v1/NCT00447980

GET https://conductscience.org/api/trials/v1/NCT00447980/results?page=2

API reference For AI assistants