“An Intention-to-Treat Analysis of Rome Transplant Network Policy for Alternative Donor Search in Patients Lacking a HLA Matched Related donor”.

Abstract 1195

Poster Board I-217

The policy of the Rome Transplant Network (RTN), a metropolitan network of transplant Centers, for patients candidates to an allogeneic hematopoietic stem cell transplant (HSCT) and lacking an HLA identical sibling is the contemporary search for one the HSC alternative sources such as Matched Unrelated Donor (MUD),Cord Blood Unit (CBU) or Haploidentical Related Donor (HRD). The main aim of the RTN policy is the identification of a suitable donor in order to perform transplant in adequate timing. The selection criteria for MUD consist of a 8/8 HLA loci matching tested at low resolution for class I HLA and at high resolution (HR) for class II; one difference in C Ag is considered acceptable in case of both I and II class HR identity. CBU's selection criteria are instead based on cell doses (TNC≥2.5×10⁷/kg and CD34+≥1× 10⁵/kg) and on a HLA-compatibility ≥to 4/6 HLA Ag. From April 2006, the haplodentical option was also simultaneously considered, so all closer family members have been tested for the HLA. Here, we report the results of the intention to treat (ITT) analysis on the potential therapeutic impact of our transplant policy. Data were obtained from RTN database. From April 2006 to date, 196 pts have been candidated to receive an allogeneic HSCT for hematological disease. Sixty-six out of 196 (34%) underwent HSCT from HLA identical sibling, while a search process for an alternative donor was activated for 130 pts. Of 130 pts, 9 (7%) lost the eligibility to transplant early during the search process and 19 (15%) died of early disease progression in most cases: a suitable MUD or CBU had been identified for 13 of 19 within 3 months from the start of the search and only 6 pts (5%) died without an alternative donor had been found. To date, 73/102 evaluable pts (72%) lacking an HLA identical sibling have been transplanted (n=66: 23 MUD; 24 CBU; 19 HRD) or are willing to proceed towards the transplant (n=7: 3 MUD;2 CBU; 2 HRD). In summary, for all 196 candidates to an allogeneic transplant the eligibility was confirmed for 187 (95%), a suitable donor could be identified for 181 (92%) of all pts or 97% of the eligible ones and an allogeneic transplant could be performed for 168 (86%) of all candidates or 93% of those eligible. From this ITT analysis, we can conclude that, by adopting the RTN policy of widespread donor search and multiple transplant options, the allogeneic transplant can be offered as potential therapeutic procedure to a large majority of pts.