Sharon Adams, Brian C. Shaffer, Robert Korngold, Seth M. Steinberg, David F. Stroncek, David Halverson, Bazetta Blacklock-Schuver, Dennis L. Confer, Jennifer Mann, Michael R. Bishop, Juan Gea-Banacloche, Daniele Avila, Daniel H. Fowler, Thomas E. Hughes, Jennifer Wilder, Jennifer Hsu, Jennifer Hendricks, Ronald E. Gress, Thea M. Friedman, Lauren M. Curtis, Frances T. Hakim, Steven Z. Pavletic, Filip Pirsl, and Rachel B. Salit
Introduction: Allogeneic hematopoietic stem cell transplantation (alloHSCT) can provide a curative therapy for hematological malignancies but may result in complications such as relapse, infection, and acute and chronic graft versus host disease (GVHD). Two divergent approaches to GVHD prophylaxis (post-HSCT depletion of donor lymphocytes vs. suppression of immune activation) in a reduced-intensity, matched-unrelated donor setting were compared in a randomized, open label, phase 2 prospective trial (NCT00520130), powered to assess the incidence of severe cGVHD using NIH criteria. Methods: Hematological malignancy patients received disease-specific induction chemotherapy DA-EPOCH-FR or FLAG (Salit et al, JCO 2012; 30:830) for disease control and host lymphodepletion to CD4+ cell target Results: 81 pts (NHL=25, HL=8, CLL=18, AML/MDS=10, CML=3, CTCL/PTCL=5, ALL=4, MM=2, other=6), median age 50 yrs (range, 21-71) were included in the study (AC=42, TMS=39). The two arms were similar in age, gender, disease, relapse risk (Kahl), HCT-comorbidity index, and donor HLA match (8/8 or 7/8). Median time to neutrophil engraftment was 9 vs. 11 days in AC vs. TMS, respectively (p=0.017). There were no differences in platelet recovery (p=0.96). One case of graft failure occurred in a myeloma patient on the AC arm. D100 mortality probabilities were 12% (95% CI, 5-25) and 10% (95% CI, 4-24) in AC and TMS, respectively (p=0.20). Median survival in AC was 18.8 mo and 41.7 mo in TMS, with a median follow-up of 53 mo in AC and 50.6 mo in TMS. 3yr OS was comparable: AC 42% (95% CI, 28-57) vs. TMS 58% (95% CI, 42-73) (p=0.20). The 3yr malignancy progression rate was higher in the AC arm (AC 51% (95% CI, 34-65) vs. TMS 21% (95% CI, 10-35), p= 0.0062). 3yr relapse related mortality rates were 29% (95% CI, 16-44) vs. 14% (95% CI, 5-29) (p=0.067) and non-relapse mortality 29% (95% CI, 16-43) vs. 28% (95% CI, 14-43) (p=0.75) in AC vs. TMS, respectively. The most common grade ≥3 adverse events (CTCAE 4.03) within 100 d post-transplant were infections (22%) with more viral infections in the AC arm (p=0.0007). Reactivation of CMV occurred earlier in the AC arm, incidence 58% (95% CI, 42-71) vs. 24% (95% CI, 12-38) by D100 (p=0.035). Rates of aGVHD were similar; Gr II-IV at 6 mo in AC 38% (95% CI, 23-53) vs. TMS 41% (95% CI, 26-57) (p=0.59); Gr III-IV at 6 mo AC 21% (95% CI, 11-35) vs. TMS 13% (95% CI, 5-26) (p=0.61). In contrast, significantly lower rates of any grade cGVHD occurred in the AC arm compared to TMS at 36 mo (27% (95% CI, 14-41) vs. 59% (95% CI, 40-74)) (p=0.0076). The incidence of severe cGVHD was strikingly different: AC 5% (95% CI, 1-15) vs. TMS 31% (95% CI, 16-47) (p=0.0007). In the Cox model, the only prognostic factor for severe or any cGVHD was the TMS treatment arm, HR 6.8 (95% CI, 1.5-30.3, p=0.012) and HR 2.3 (95% CI, 1.1-4.8, p=0.026), respectively. Lymphocyte recovery (ALC 500/µL) was markedly delayed in AC, median 76 vs. 16 d (p Conclusions: This prospective, randomized trial demonstrates that the use of AC when compared with TMS led to a significant reduction in incidence of severe and overall cGVHD. These two GVHD prophylaxis regimens had similar incidences of aGVHD but very different effects on post-alloHSCT immune reconstitution, infection and relapse. Future strategies for cGVHD prevention will need to further address these issues. Disclosures Off Label Use: There is currently no FDA approved product for GVHD prevention or therapy. The GVHD prophylaxis regimens described in this study (Alemtuzumab-Cyclosporine and Tacrolimus-Methotrexate-Sirolimus) are used off-label as GVHD prophylaxis regimens in reduced-intensity allogeneic HSCT.