Trial Outcomes & Findings for Efficacy of Pre-exposure Treatment With Hydroxy-Chloroquine on the Risk and Severity of COVID-19 Infection (NCT NCT04481633)

NCT ID: NCT04481633

Last Updated: 2026-08-10

Results Overview

Number of patients with positive anti-COVID19 serology depending on whether or not they were taking Hydroxy-Chloroquine

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

547 participants

Primary outcome timeframe

12 months post inclusion

Results posted on

2026-08-10

Participant Flow

Participant milestones

Participant milestones
Measure
HCQ+IS+ Group
Patients treated with Hydroxychloroquine and Immunosuppressants with SLE/GS or other connective tissue disease
HCQ+IS- Group
Patients treated with Hydroxychloroquine and without immunosuppressants with SLE/GS or other connective tissue disease diagnosed
HCQ-IS+ Group
Patients not treated with Hydroxychloroquine and Immunosuppressants with a diagnosis of SLE/GS or other connective tissue disease
HCQ-IS- Group
Patients not treated with Hydroxychloroquine and without immunosuppressants with viral Hepatitis C cured for more than 12 months or primary biliary cholangitis (PBC)
Overall Study
STARTED
112
121
115
199
Overall Study
COMPLETED
50
54
54
112
Overall Study
NOT COMPLETED
62
67
61
87

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Race and Ethnicity were not collected from any participant.

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
HCQ+IS+ Group
n=112 Participants
Patients treated with Hydroxychloroquine and Immunosuppressants with SLE/GS or other connective tissue disease
HCQ+IS- Group
n=121 Participants
Patients treated with Hydroxychloroquine and without immunosuppressants with SLE/GS or other connective tissue disease diagnosed
HCQ-IS+ Group
n=115 Participants
Patients not treated with Hydroxychloroquine and Immunosuppressants with a diagnosis of SLE/GS or other connective tissue disease
HCQ-IS- Group
n=199 Participants
Patients not treated with Hydroxychloroquine and without immunosuppressants with viral Hepatitis C cured for more than 12 months or primary biliary cholangitis (PBC)
Total
n=547 Participants
Total of all reporting groups
Age, Continuous
47.50 Years
STANDARD_DEVIATION 13.23 • n=112 Participants
45.73 Years
STANDARD_DEVIATION 13.60 • n=121 Participants
55.52 Years
STANDARD_DEVIATION 30.47 • n=115 Participants
61.47 Years
STANDARD_DEVIATION 12.14 • n=199 Participants
53.95 Years
STANDARD_DEVIATION 19.17 • n=547 Participants
Sex: Female, Male
Female
104 Participants
n=112 Participants
107 Participants
n=121 Participants
90 Participants
n=115 Participants
117 Participants
n=199 Participants
418 Participants
n=547 Participants
Sex: Female, Male
Male
8 Participants
n=112 Participants
14 Participants
n=121 Participants
25 Participants
n=115 Participants
82 Participants
n=199 Participants
129 Participants
n=547 Participants
Race and Ethnicity Not Collected
0 Participants
Race and Ethnicity were not collected from any participant.
Polymedicated patient
72 Participants
n=112 Participants
49 Participants
n=121 Participants
60 Participants
n=115 Participants
71 Participants
n=199 Participants
252 Participants
n=547 Participants

PRIMARY outcome

Timeframe: 12 months post inclusion

Number of patients with positive anti-COVID19 serology depending on whether or not they were taking Hydroxy-Chloroquine

Outcome measures

Outcome measures
Measure
HCQ+IS+ Group
n=112 Participants
Patients treated with Hydroxychloroquine and Immunosuppressants with SLE/GS or other connective tissue disease
HCQ+IS- Group
n=121 Participants
Patients treated with Hydroxychloroquine and without immunosuppressants with SLE/GS or other connective tissue disease diagnosed
HCQ-IS+ Group
n=115 Participants
Patients not treated with Hydroxychloroquine and Immunosuppressants with a diagnosis of SLE/GS or other connective tissue disease
HCQ-IS- Group
n=199 Participants
Patients not treated with Hydroxychloroquine and without immunosuppressants with viral Hepatitis C cured for more than 12 months or primary biliary cholangitis (PBC)
Number of Participants With Positive Anti-SARS-CoV-2 Serology
31 Participants
30 Participants
12 Participants
30 Participants

SECONDARY outcome

Timeframe: From inclusion until the end of the study (at M12)

Percentage of patients who experienced symptomatic or severe (hospitalization) COVID-19 infection, as determined by the self-administered questionnaire and medical consultation. Each subject will complete a self-administered questionnaire at the enrollment visit, describing the main symptoms of COVID-19 infection by answering "yes" or "no" to the various items. The physician will then conduct a medical assessment of the symptoms and their severity.

Outcome measures

Outcome measures
Measure
HCQ+IS+ Group
n=112 Participants
Patients treated with Hydroxychloroquine and Immunosuppressants with SLE/GS or other connective tissue disease
HCQ+IS- Group
n=121 Participants
Patients treated with Hydroxychloroquine and without immunosuppressants with SLE/GS or other connective tissue disease diagnosed
HCQ-IS+ Group
n=115 Participants
Patients not treated with Hydroxychloroquine and Immunosuppressants with a diagnosis of SLE/GS or other connective tissue disease
HCQ-IS- Group
n=199 Participants
Patients not treated with Hydroxychloroquine and without immunosuppressants with viral Hepatitis C cured for more than 12 months or primary biliary cholangitis (PBC)
Number of Patients Who Experienced Symptomatic or Severe (Hospitalization) COVID-19 Infection
23 Participants
17 Participants
7 Participants
18 Participants

OTHER_PRE_SPECIFIED outcome

Timeframe: 12 months post inclusion

Population: The discrepancy between the number of participants analyzed in this OM and the overall number reported in the Participants Flow section is due to missing data; some patients did not have these data available.

Percentage of patients with anti-COVID19 serology indicating effective vaccine protection. Vaccine protection efficacy is measured by the presence of a post-vaccination antibody titer greater than 140 BAU/mL.

Outcome measures

Outcome measures
Measure
HCQ+IS+ Group
n=64 Participants
Patients treated with Hydroxychloroquine and Immunosuppressants with SLE/GS or other connective tissue disease
HCQ+IS- Group
n=72 Participants
Patients treated with Hydroxychloroquine and without immunosuppressants with SLE/GS or other connective tissue disease diagnosed
HCQ-IS+ Group
n=74 Participants
Patients not treated with Hydroxychloroquine and Immunosuppressants with a diagnosis of SLE/GS or other connective tissue disease
HCQ-IS- Group
n=139 Participants
Patients not treated with Hydroxychloroquine and without immunosuppressants with viral Hepatitis C cured for more than 12 months or primary biliary cholangitis (PBC)
Number of Patients With Anti-COVID19 Serology Indicating Effective Vaccine Protection
48 Participants
65 Participants
65 Participants
119 Participants

OTHER_PRE_SPECIFIED outcome

Timeframe: 12 months post iclusion

Population: The discrepancy between the number of participants analyzed in this OM and the overall number reported in the Participants Flow section is due to missing data; some patients did not have these data available.

Rate of patient with elevated post-vaccination antibody titers according to treatment type and group

Outcome measures

Outcome measures
Measure
HCQ+IS+ Group
n=61 Participants
Patients treated with Hydroxychloroquine and Immunosuppressants with SLE/GS or other connective tissue disease
HCQ+IS- Group
n=71 Participants
Patients treated with Hydroxychloroquine and without immunosuppressants with SLE/GS or other connective tissue disease diagnosed
HCQ-IS+ Group
n=72 Participants
Patients not treated with Hydroxychloroquine and Immunosuppressants with a diagnosis of SLE/GS or other connective tissue disease
HCQ-IS- Group
n=138 Participants
Patients not treated with Hydroxychloroquine and without immunosuppressants with viral Hepatitis C cured for more than 12 months or primary biliary cholangitis (PBC)
Number of Participants With Elevated Post-vaccination Antibody Titer
22 Participants
36 Participants
25 Participants
41 Participants

OTHER_PRE_SPECIFIED outcome

Timeframe: 12 months post inclusion

Number of patients who accepted the anti-COVID-19 vaccination, which allows us to obtain the acceptance rate of the Covid-19 vaccination according to the 4 groups studied in the protocol

Outcome measures

Outcome measures
Measure
HCQ+IS+ Group
n=112 Participants
Patients treated with Hydroxychloroquine and Immunosuppressants with SLE/GS or other connective tissue disease
HCQ+IS- Group
n=121 Participants
Patients treated with Hydroxychloroquine and without immunosuppressants with SLE/GS or other connective tissue disease diagnosed
HCQ-IS+ Group
n=115 Participants
Patients not treated with Hydroxychloroquine and Immunosuppressants with a diagnosis of SLE/GS or other connective tissue disease
HCQ-IS- Group
n=199 Participants
Patients not treated with Hydroxychloroquine and without immunosuppressants with viral Hepatitis C cured for more than 12 months or primary biliary cholangitis (PBC)
Number of Patients Who Accepted the Anti-COVID-19 Vaccination
76 Participants
83 Participants
86 Participants
148 Participants

Adverse Events

HCQ+IS+ Group

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

HCQ+IS- Group

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

HCQ-IS+ Group

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

HCQ-IS- Group

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Pr Laurent ALRIC

Service de Médecine Interne-Immunologie clinique Pole Digestif Hôpital de Rangueil, CHU Toulouse

Phone: 05 61 32 29 09

Results disclosure agreements

  • Principal investigator is a sponsor employee
  • Publication restrictions are in place