Graft-versus-host disease is a complication of allogeneic hematopoietic cell transplantation with high morbidity and mortality. The standard treatment is corticosteroids, and based on the response within 3 to 7 days, a second-line therapy is added, which is expensive and not easily accessible. The administration of human chorionic gonadotropin has shown therapeutic effectiveness in 50% of patients in reported clinical cases.

The study will include 20 patients with recent-onset allogeneic hematopoietic cell transplantation and GVHD who attend the Hematology Service at the University Hospital and meet the inclusion criteria, to receive conventional treatment with steroids (prednisone 1 mg/kg/day for 14 days) or combined treatment (hCG 2500 IU, IM + prednisone 1 mg/kg/day for 14 days).

Inclusion Criteria:

• Aged 18 years or older.
• Any gender.
• Post-allogeneic transplantation status (haploidentical or identical) of hematopoietic cells.
• Presenting recently onset aGVHD, grades 2 to 4, and requiring systemic steroid use as determined by the treating physician.
• Have not received steroids (Prednisone ≥1 mg/kg/day or equivalent dose of another steroid) for more than 3 days in the last week.
• Willing to participate in the study by signing informed consent.
• If the subject is female and has the potential to procreate (a woman is considered fertile from menarche to postmenopausal stage or after undergoing a permanent contraceptive method), she agrees to use one of the following contraceptive methods from the start of the study and for 30 days after the protocol: oral hormonal contraception, intrauterine device, barrier methods (diaphragm, male or female condom, and foam, sponge, or spermicide film), or agrees to remain abstinent. Women who have been postmenopausal for more than a year, undergone hysterectomy, bilateral oophorectomy, or bilateral salpingectomy are not considered to have reproductive potential.
• If the subject is male, he agrees to use one of the following contraceptive methods from the start of the study and for 30 days after the protocol: male condom, or remain abstinent.

Exclusion Criteria:

• Arterial or venous thrombosis in the past 3 months.
• History of thromboembolic disease requiring full-dose anticoagulation.
• Diagnosis of active malignant disease.
• Uncontrolled infection.
• Chronic use of supplemental therapy with sex hormones (estrogen, progesterone, and/or testosterone).
• Women with a positive pregnancy test at the time of the initial evaluation.
• Women or men of reproductive age who are unwilling to take appropriate precautions to avoid an unwanted pregnancy from the start of the protocol until 30 days after the protocol.