Study of Pregnyl as Adjunct Therapy for High-Risk or Refractory Acute GVHD

"Standard of care immunosuppression, plus Pregnyl® at assigned dose subcutaneously every other day for up to 5 doses through day 7~Phase I: up to 7 dose levels of Pregnyl® will be tested; however dose levels -1 and -2 will be used only if dose level 1 proves too toxic. Study will use Continual Reassessment Method (CRM) to establish a maximum tolerated dose (MTD).~Step -2: 125 USP hCG/875 pg EGF/m2 Step -1: 250 USP hCG/1,750 pg EGF/m2 Step 1 (start): 500 USP hCG/3,500 pg EGF/m2 Step 2: 1,000 USP hCG/7,000 pg EGF/m2 Step 3: 2,000 USP hCG/14,000 pg EGF/m2 Step 4 (Arm 2b only): 3,500 USP hCG/24,500 pg EGF/m2 Step 5 (Arm 2b only): 5,000 USP hCG/35,000 pg EGF/m~Phase II: the dose of Pregnyl will be that identified as the MTD during phase I."