Trial · NCT01733316

Open-Label, Safety and Superior Effectiveness Study of Cysteamine Bitartrate Delayed-Release Capsules (RP103) in Cystinosis

NCT01733316, Phase 3, Completed, Amgen; results first posted 2017-05-24

3 sourcestrials-2026-11-12-0.5.0

Cite this record

ConductScience Library. Open-Label, Safety and Superior Effectiveness Study of Cysteamine Bitartrate Delayed-Release Capsules (RP103) in Cystinosis. Trials, record NCT01733316. Release trials-2026-11-12-0.5.0, 12 Nov 2026. https://conductscience.org/library/trials/NCT01733316

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Trial

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

Title: Open-Label, Safety and Superior Effectiveness Study of Cysteamine Bitartrate Delayed-Release Capsules (RP103) in Cystinosis
NCT number: NCT01733316
Status: Completed
Phases: Phase 3
Enrollment: 41 participants, actual
Lead sponsor: Amgen
Conditions: Cystinosis
Interventions: RP103, Cystagon®
First posted: 2012-11-27
Last updated: 2024-12-27
Other registries' IDs: eudract:2012-002773-64
Results first posted: 2017-05-24

Source ClinicalTrials.gov

Registered outcomes6

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

List	Outcome	Time frame	Description
Primary	Average Difference Between Morning and Non-Morning Log White Blood Cell (WBC) Cystine Values	While taking Cystagon® (Months 1, 2, 3): within 15 minutes pre-morning (AM) and pre-non AM dose. During 3 months of RP103 (Months 5, 6, 7): 30 minutes post-AM and post-evening (PM) dose.	The primary analysis of WBC cystine was performed using the natural log transformed WBC cystine level; the log transformation is a normalizing transformation. For each participant, the difference between the morning and corresponding non-morning log WBC cystine value (non-morning minus morning) at each monthly visit during the Cystagon® phase (Months 1, 2, and 3) was computed and these differences were averaged. The average difference between morning and non-morning log WBC cystine value was similarly computed for each participant during the RP103 phase (Months 5, 6, and 7). The primary analysis compared within-subject pairs (Cystagon® phase paired with RP103 phase) of non-morning minus morning average differences of log WBC cystine level.
Secondary	Number of Participants With Treatment-Emergent Adverse Events (AEs), Serious Adverse Events (SAEs), and Discontinuations Due to AEs	From first dose of study drug to 7 days after last dose. Median duration of exposure was 91 days (range 82-108) for Cystagon® phase, 119 days (range 98-137) for the RP103 phase, and 861 days (range 30 - 1350) during the long-term RP-103 phase.	AE: any untoward medical occurrence that does not necessarily have a causal relationship with study drug. SAE: any untoward medical occurrence that at any dose: results in death; is life threatening; requires inpatient hospitalization or prolongation of existing hospitalization; results in persistent or significant disability or incapacity; is a congenital anomaly or birth defect; or is medically significant, and though not included in the above list, is an important medical event, according to the Investigator. Treatment-emergent adverse events (TEAEs) occurred after first dose of study drug. Clinically significant abnormalities in laboratory values (hematology, blood chemistry, urinalysis), electrocardiograms (ECGs), vital signs, and physical examinations were to be reported as adverse events and so are included in this summary of TEAEs
Secondary	Halitosis Substudy: Maximum Plasma Concentration (Cmax) for Plasma Cysteamine	While taking Cystagon® (Month 1, 2 or 3): Within 15 minutes prior to morning dose, 30 minutes post-dose, 1, 2, 4 and 6 hours post-dose. While taking RP103 (Month 5, 6, or 7): 30 minutes after morning dose and 1, 2, 3, 4, 6, 8, 10, 12 hours post-dose	Participants who reported halitosis ("bad breath") as a side effect while receiving Cystagon® were asked to participate in a substudy to investigate the concentration of dimethylsulfide (DMS) in expired air after the administration of study medication. To assess halitosis during study medication treatment, the steady state pharmacokinetic (PK) samples of cysteamine and DMS were collected over a 6 hour period when Cystagon® was administered and over a 12 hour period when RP103 was administered.
Secondary	Halitosis Substudy: Time to Cmax (Tmax) for Plasma Cysteamine	While taking Cystagon® (Month 1, 2 or 3): Within 15 minutes prior to morning dose, 30 minutes post-dose, 1, 2, 4 and 6 hours post-dose. While taking RP103 (Month 5, 6, or 7): 30 minutes after morning dose and 1, 2, 3, 4, 6, 8, 10, 12 hours post-dose	Participants who reported halitosis ("bad breath") as a side effect while receiving Cystagon® were asked to participate in a substudy to investigate the concentration of DMS in expired air after the administration of study medication. To assess halitosis during study medication treatment, the steady state PK samples of cysteamine and DMS were collected over a 6 hour period when Cystagon® was administered and over a 12 hour period when RP103 was administered.
Secondary	Area Under the Plasma Concentration Time Curve From Time Point 0 Through the Last Measurable Point (AUC0-t) for Plasma Cysteamine	While taking Cystagon® (Month 1, 2 or 3): Within 15 minutes prior to morning dose, 30 minutes post-dose, 1, 2, 4 and 6 hours post-dose. While taking RP103 (Month 5, 6, or 7): 30 minutes after morning dose and 1, 2, 3, 4, 6, 8, 10, 12 hours post-dose	Participants who reported halitosis ("bad breath") as a side effect while receiving Cystagon® were asked to participate in a substudy to investigate the concentration of DMS in expired air after the administration of study medication. To assess halitosis during study medication treatment, the steady state PK samples of cysteamine and DMS were collected over a 6 hour period when Cystagon® was administered and over a 12 hour period when RP103 was administered.
Secondary	Halitosis Substudy: Expired Air DMS Concentrations	While taking Cystagon® (Month 1, 2 or 3): Within 15 minutes prior to morning dose 30 min post-dose, 2, 3, 4 and 6 hours post-dose. While taking RP103 (Month 4, 5, or 7): Within 15 min. prior to morning dose. 1, 2, 3, 4, 5, 6, 8, 10, 12 hours post dose	Participants who reported halitosis ("bad breath") as a side effect while receiving Cystagon® were asked to participate in a substudy to investigate the concentration of DMS in expired air after the administration of study medication. To assess halitosis during study medication treatment, the steady state PK samples of cysteamine and DMS were collected over a 6 hour period when Cystagon® was administered and over a 12 hour period when RP103 was administered.

Source ClinicalTrials.gov

Outcomes6

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

Type	Outcome	Time frame	Population	Units	Measured as
PRIMARY	Average Difference Between Morning and Non-Morning Log White Blood Cell (WBC) Cystine Values	While taking Cystagon® (Months 1, 2, 3): within 15 minutes pre-morning (AM) and pre-non AM dose. During 3 months of RP103 (Months 5, 6, 7): 30 minutes post-AM and post-evening (PM) dose.	Pharmacodynamic (PD) Analysis Set: All participants who received at least one treatment of Cystagon® and RP103 and who had at least one WBC cystine level recorded after each of Cystagon® treatment and RP103 treatment. Only participants with an average difference during both the Cystagon® and RP103 phases were included.	log [nmol ½ cystine/mg protein]	MEAN
SECONDARY	Number of Participants With Treatment-Emergent Adverse Events (AEs), Serious Adverse Events (SAEs), and Discontinuations Due to AEs	From first dose of study drug to 7 days after last dose. Median duration of exposure was 91 days (range 82-108) for Cystagon® phase, 119 days (range 98-137) for the RP103 phase, and 861 days (range 30 - 1350) during the long-term RP-103 phase.	Safety Analysis Set: all participants who received at least 1 dose of study drug (RP103). The row At least 1 TEAE includes both serious and non-serious AEs.	Participants	COUNT_OF_PARTICIPANTS
SECONDARY	Halitosis Substudy: Maximum Plasma Concentration (Cmax) for Plasma Cysteamine	While taking Cystagon® (Month 1, 2 or 3): Within 15 minutes prior to morning dose, 30 minutes post-dose, 1, 2, 4 and 6 hours post-dose. While taking RP103 (Month 5, 6, or 7): 30 minutes after morning dose and 1, 2, 3, 4, 6, 8, 10, 12 hours post-dose	PK Analysis Set: All participants who received at least one dose of RP103 and had available PK data at given timepoint.	mg/L	MEAN
SECONDARY	Halitosis Substudy: Time to Cmax (Tmax) for Plasma Cysteamine	While taking Cystagon® (Month 1, 2 or 3): Within 15 minutes prior to morning dose, 30 minutes post-dose, 1, 2, 4 and 6 hours post-dose. While taking RP103 (Month 5, 6, or 7): 30 minutes after morning dose and 1, 2, 3, 4, 6, 8, 10, 12 hours post-dose	PK Analysis Set: All participants who received at least one dose of RP103 and had available PK data at given timepoint.	hour	MEAN
SECONDARY	Area Under the Plasma Concentration Time Curve From Time Point 0 Through the Last Measurable Point (AUC0-t) for Plasma Cysteamine	While taking Cystagon® (Month 1, 2 or 3): Within 15 minutes prior to morning dose, 30 minutes post-dose, 1, 2, 4 and 6 hours post-dose. While taking RP103 (Month 5, 6, or 7): 30 minutes after morning dose and 1, 2, 3, 4, 6, 8, 10, 12 hours post-dose	PK Analysis Set: All participants who received at least one dose of RP103 and had available PK data at given timepoint.	hr*mg/L	MEAN
SECONDARY	Halitosis Substudy: Expired Air DMS Concentrations	While taking Cystagon® (Month 1, 2 or 3): Within 15 minutes prior to morning dose 30 min post-dose, 2, 3, 4 and 6 hours post-dose. While taking RP103 (Month 4, 5, or 7): Within 15 min. prior to morning dose. 1, 2, 3, 4, 5, 6, 8, 10, 12 hours post dose	PK Analysis Set: All participants who received at least one dose of RP103 and had available PK data at given timepoint.	nmol/L	MEAN

Source ClinicalTrials.gov

Results by group40

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

Outcome	Group	Category	Value	Spread	Units
Average Difference Between Morning and Non-Morning Log White Blood Cell (WBC) Cystine Values	Cystagon® Phase		-0.229	Standard Deviation 0.5027	log [nmol ½ cystine/mg protein]
Average Difference Between Morning and Non-Morning Log White Blood Cell (WBC) Cystine Values	RP103 Phase		0.080	Standard Deviation 0.3939	log [nmol ½ cystine/mg protein]
Number of Participants With Treatment-Emergent Adverse Events (AEs), Serious Adverse Events (SAEs), and Discontinuations Due to AEs	Cystagon® Phase	At least 1 TEAE	31		Participants
Number of Participants With Treatment-Emergent Adverse Events (AEs), Serious Adverse Events (SAEs), and Discontinuations Due to AEs	RP103 Phase	At least 1 TEAE	38		Participants
Number of Participants With Treatment-Emergent Adverse Events (AEs), Serious Adverse Events (SAEs), and Discontinuations Due to AEs	Long-Term Phase	At least 1 TEAE	32		Participants
Number of Participants With Treatment-Emergent Adverse Events (AEs), Serious Adverse Events (SAEs), and Discontinuations Due to AEs	Cystagon® Phase	At least 1 TEAE-related to study drug	4		Participants
Number of Participants With Treatment-Emergent Adverse Events (AEs), Serious Adverse Events (SAEs), and Discontinuations Due to AEs	RP103 Phase	At least 1 TEAE-related to study drug	20		Participants
Number of Participants With Treatment-Emergent Adverse Events (AEs), Serious Adverse Events (SAEs), and Discontinuations Due to AEs	Long-Term Phase	At least 1 TEAE-related to study drug	18		Participants
Number of Participants With Treatment-Emergent Adverse Events (AEs), Serious Adverse Events (SAEs), and Discontinuations Due to AEs	Cystagon® Phase	At least 1 grade ≥ 3 TEAE	5		Participants
Number of Participants With Treatment-Emergent Adverse Events (AEs), Serious Adverse Events (SAEs), and Discontinuations Due to AEs	RP103 Phase	At least 1 grade ≥ 3 TEAE	4		Participants

1 to 10 of 40Source ClinicalTrials.gov

See all 40 results by group

Participant flow9

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

Period	Milestone	Group	Participants
Cystagon® Phase	STARTED	All Participants	41
Cystagon® Phase	COMPLETED	All Participants	41
Cystagon® Phase	NOT COMPLETED	All Participants	0
RP103 Phase	STARTED	All Participants	41
RP103 Phase	COMPLETED	All Participants	40
RP103 Phase	NOT COMPLETED	All Participants	1
Long Term Extension Phase	STARTED	All Participants	38
Long Term Extension Phase	COMPLETED	All Participants	33
Long Term Extension Phase	NOT COMPLETED	All Participants	5

Source ClinicalTrials.gov

Adverse events255

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
other	Anaemia	Blood and lymphatic system disorders	Cystagon® Phase	0	41
other	Anaemia	Blood and lymphatic system disorders	RP103 Phase	1	41
other	Anaemia	Blood and lymphatic system disorders	Long-Term Phase	4	38
other	Conjunctivitis	Eye disorders	Cystagon® Phase	0	41
other	Conjunctivitis	Eye disorders	RP103 Phase	1	41
other	Conjunctivitis	Eye disorders	Long-Term Phase	3	38
other	Abdominal pain	Gastrointestinal disorders	Cystagon® Phase	1	41
other	Abdominal pain	Gastrointestinal disorders	RP103 Phase	3	41
other	Abdominal pain	Gastrointestinal disorders	Long-Term Phase	5	38
other	Abdominal pain upper	Gastrointestinal disorders	Cystagon® Phase	2	41

1 to 10 of 255Source ClinicalTrials.gov

See all 255 adverse events

Adverse event totals9

The totals the trial posted for each group.

Total	Group	Affected	At risk
Total, all-cause mortality	Cystagon® Phase	0	41
Total, all-cause mortality	RP103 Phase	0	41
Total, all-cause mortality	Long-Term Phase	1	38
Total, other adverse events	Cystagon® Phase	28	41
Total, other adverse events	RP103 Phase	33	41
Total, other adverse events	Long-Term Phase	32	38
Total, serious adverse events	Cystagon® Phase	5	41
Total, serious adverse events	RP103 Phase	6	41
Total, serious adverse events	Long-Term Phase	13	38

Source ClinicalTrials.gov

Papers1

The papers the trial lists on ClinicalTrials.gov.

PMID	Listed as
19158356	BACKGROUND

Source 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 comparisons0

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

None in this release.

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.

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Read this trial from software.

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