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Klinefelter Syndrome clinical trials

The registry lists 47 studies for Klinefelter Syndrome across more than 10 countries. 17 are recruiting or about to start. 31 of them are mainly about Klinefelter Syndrome (how this is decided). Per ClinicalTrials.gov, last updated 2026-10-29.

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Status

Completed
25
Recruiting
11
Enrolling by invitation
4
Not yet recruiting
2
Status unknown
2
Active, not recruiting
1

Phase

Phase 4
4
Phase 2
3
Phase 3
2
Phase 1
1

Where

United States
18
Denmark
12
Italy
3
France
3
Netherlands
3
Belgium
2

Who runs them

University of Aarhus (8) · University of Colorado, Denver (7) · dr. Laura C. G. de Graaff-Herder (3) · University of Roma La Sapienza (2) · Hospices Civils de Lyon (2) · Progenity, Inc. (2) · Odense University Hospital (2) · Boston Children's Hospital (1)

What is being tested here

Drugs under test in Klinefelter Syndrome studies, those with the most open studies first. Medicines only given beside them are not counted. How drugs are counted

DrugOpenPhase 3All
Testosterone114
Chorionic Gonadotropin112
Anastrozole111
Semaglutide111
Fenofibrate001
Isotretinoin001
Testosterone 17 beta-cypionate001
Testosterone undecanoate011
Mesenchymal Stem Cell001

Drug classes tested here Androgens 1 open

Coming up

1phase 3 study under way
3studies finish main data collection within a year1 of them phase 3

Studies recruiting or running, from their records. “Main data collection” ends at the primary completion date, the sponsor’s own estimate, which often moves.

All 3, phase 3 first

Who these studies take

Of the 11 Klinefelter Syndrome studies recruiting now, 2 (18%) set no upper age limit and 5 (45%) stop at 75 or younger. 7 (64%) take children under 18. 0 (0%) are for women only and 5 (45%) for men only; 2 (18%) take healthy volunteers.

Recruiting studies that take each age, of 11
AgeWomenMen
101 (9%)4 (36%)
185 (45%)9 (82%)
305 (45%)9 (82%)
405 (45%)9 (82%)
505 (45%)9 (82%)
655 (45%)8 (73%)
754 (36%)6 (55%)
854 (36%)5 (45%)

Across all 47 studies, recruiting or not: 64% stop at 75 or younger and 60% at 65; 60% take children; 6% are for women only and 60% for men only; 32% take healthy volunteers. From each study’s registry entry; the criteria on its page decide.

What changed recently

From the registry's own updates since Oct 14, 2026.

Newly registered1

Studies

Recruiting first, then most recently updated. Showing 47 of 47. search them.