Abstract

Abstract 222

We have previously reported the feasibility and safety of augmenting the reduced-intensity regimen (RIC) of FM by addition of total marrow irradiation, a targeted form of TBI, using a helical tomotherapy (HT) device (Rosenthal, Blood. 2011;117(1):309–315). In this study we compared outcomes in patients with acute leukemia undergoing HCT receiving either TFM or FM.

Patients and Methods:

We analyzed 72 patients with acute leukemia or MDS who received either FM (N=36) or TFM (N=36) HCT. Eligibility criteria for TFM were age > 50 years of age or compromised organ function (COF); high-risk remission or marrow blasts ≤10%. TFM patients were matched to a set of FM patients based on age, gender, diagnosis and disease risk (low, intermediate, high). All patients received FM with fludarabine 25 mg/m2/d × 5 days and melphalan140 mg/m2/d × 1 day, and TMI was delivered at 150cGy/fraction in 8 fractions over 4 days in the TFM group. Supportive care and treatment for prevention of GVHD were given according to our institution standard guidelines for both groups.

Results:

Demographic characteristics were similar, including gender (20 females, 55.6%) and age (median 58 years, range: 22–68 in TFM and 20–68 in FM). The proportions of patients by diagnoses were similar: AML (n=27), ALL (n=7), MDS (n=2). Disease risk assignments in both groups were: Low risk (n=15), intermediate (n=6), high (n=15). There were 15 and 13 pts with active disease in FM and TFM, respectively. HLA-identical siblings (n=16, 44.4%) or matched unrelated donor (n=20, 55.6%) were used in each group. Outcomes are reported for the TFM and FM recipients, respectively as follows: myeloid recovery was documented on day 13.5 (9–24) and 15 (8–20). Transplant-related toxicities were limited to grade 3 or less in both groups. The most common grade 3 toxicities were: mucositis, n=9 and n=7 and bacterial infection, n=10 and n=11, respectively. Acute GvHD grade II-IV occurred in 20 pts (55%) and 19 (53%). Extensive chronic GVHD was documented in 24 (67%) and 20 (56%) pts. Twenty-one and 18 patients are alive at a median of 30.2 months and 35.3 months in the TFM and FM, respectively. The relapse cumulative incidence at 2 years post HCT was 11.1% (TFM) compared to 30.6% (FM) (p=0.06) (insert ). With a median follow-up of 31.7 months (4.1 – 62.5) for alive patients, the 2-year overall and progression-free survival estimates are 57.2 % (95% CI, 46.6–66.4) -TFM, and 62.8% (95% CI, 51.8–72.0) -FM, and 57.7% (95% CI, 47.2–67.0) -TFM, and 48.5% (95% CI, 40.2–56.3) -FM, respectively.

Conclusion:

The addition of TMI at a dose of 1200 cGy to FM is safe and tolerable and may decrease the risk of relapse related mortality.

Disclosures:

No relevant conflicts of interest to declare.

Author notes

*

Asterisk with author names denotes non-ASH members.