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Phase III Trial With Caplacizumab in Patients With Acquired Thrombotic Thrombocytopenic Purpura

Phase 3
Completed
Conditions
Acquired Thrombotic Thrombocytopenic Purpura
Registration Number
NCT02553317
Lead Sponsor
Ablynx, a Sanofi company
Brief Summary

The study was a Phase III, double-blind, placebo-controlled, randomized study to evaluate the efficacy of caplacizumab in more rapidly restoring normal platelet counts as measure of prevention of further microvascular thrombosis

Detailed Description

Not available

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
145
Inclusion Criteria
  1. Adult male or female ≥ 18 years of age at the time of signing the informed consent form (ICF).
  2. Clinical diagnosis of acquired thrombotic thrombocytopenic purpura (aTTP) (initial or recurrent), which included thrombocytopenia and microscopic evidence of red blood cell fragmentation (e.g., schistocytes).
  3. Required initiation of daily PE treatment and had received 1 PE treatment prior to randomization
  4. Others as defined in the protocol
Exclusion Criteria
  1. Platelet count ≥100×10E9/L.
  2. Serum creatinine level >200 µmol/L in case platelet count is > 30×10E9/L
  3. Known other causes of thrombocytopenia
  4. Congenital TTP (known at the time of study entry).
  5. Pregnancy or breast-feeding.
  6. Subjects who were previously enrolled in a clinical study with caplacizumab and received caplacizumab or for whom the assigned treatment arm is unknown
  7. Others as defined in the protocol

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Primary Outcome Measures
NameTimeMethod
Time to Platelet Count ResponseOnly data from the DB daily PE period (median = 5 days) up to the cut-off were used. The cut-off point was defined by whichever occured first: 1) 45 days of daily PE after start of study drug, 2) stop of daily PE, 3) stop of study drug (median = 34 days)

Platelet count response was defined as initial platelet count ≥ 150,000/μL with subsequent stop of daily PE within 5 days. It refers to the first time both conditions, platelet count ≥ 150,000/μL and the stop of daily PE within 5 days, were met.

Secondary Outcome Measures
NameTimeMethod
Number and Percentage of Subjects With Refractory DiseaseThe study drug treatment period, a median (min, max) of 36 (2, 82) days.

Number and percentage of subjects with refractory TTP, defined as absence of platelet count doubling after 4 days of standard treatment, and lactate dehydrogenase (LDH) \> upper limit of normal (ULN) (i.e., third key secondary endpoint).

Number and Percentage of Subjects With TTP-Related Death, Recurrence of TTP, or a Major Thromboembolic Event During the Study Drug Treatment PeriodThe study drug treatment period, a median (min, max) of 36 (2, 82) days. For both treatment groups, only events that occurred prior to a switch to open-label caplacizumab were evaluated for this analysis.

Number and percentage of subjects with TTP-related death, a recurrence of TTP, or at least one treatment-emergent major thromboembolic event during the study drug treatment period (i.e., first key secondary endpoint).

Time to Normalization of Organ Damage Marker LevelsOverall study period, a median (min, max) of 65 (2, 110) days. For both treatment groups, normalizations occurring during the open-label period were not evaluated in this analysis.

Time to first normalization of LDH, cardiac troponin I (cTnI) and serum creatinine was defined as: first time of LDH ≤ ULN and cTnI ≤ ULN and serum creatinine ≤ ULN - time of first i.v. loading dose of study drug after randomization + 1 minute. Subjects in either initial treatment group who switched to open-label caplacizumab before having reached the endpoint were censored at time of switch.

Of note, the key secondary endpoints were hierarchically ordered to allow statistical testing for these endpoints at the same nominal significance level of 5% without adjustment, as long as the tests occurred in the pre-defined sequential order, and given that all null hypotheses tested for endpoints with a higher rank (including the primary endpoint) were rejected. No confirmatory testing was done for this fourth key secondary endpoint, as the statistical test was not significant for the proportion of subjects with refractory disease (i.e., the third key secondary endpoint).

Number and Percentage of Subjects With a Recurrence of TTP in the Overall Study PeriodThe overall study period (covers both the overall treatment period and the follow-up period), a median (min, max) of 65 (2, 110) days.

Number and percentage of subjects with a recurrence of TTP during the Overall Study Period (i.e., including follow-up \[FU\]) (i.e., second key secondary endpoint).

Trial Locations

Locations (13)

Investigator Site

🇬🇧

Liverpool, United Kingdom

Investigator SIte

🇺🇸

Cleveland, Ohio, United States

Investigator Site 1

🇬🇧

London, United Kingdom

Investigator Site 2

🇬🇧

London, United Kingdom

Investigator Site 3

🇫🇷

Paris, France

Investigator Site 4

🇫🇷

Paris, France

Investigator Site 5

🇦🇺

Melbourne, Australia

Invesigator Site

🇨🇦

Montreal, Quebec, Canada

Investigator site 5

🇫🇷

Paris, France

Investigator site 1

🇩🇪

Dresden, Germany

Scroll for more (3 remaining)
Investigator Site
🇬🇧Liverpool, United Kingdom

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