Impact of positron emission tomography - computed tomography status on progression-free survival for relapsed follicular lymphoma patients undergoing autologous stem cell transplantation.

The optimum management approach for patients with relapsed or refractory follicular lymphoma remains uncertain. Autologous stem cell transplantation (autoSCT) is considered a standard option in suitable, younger patients with relapsed follicular lymphoma. AutoSCT is associated with very durable remissions in a minority of subjects, but also with significant, well-established toxicities. Although positron emission tomography (PET) status prior to autoSCT is an established prognostic factor in diffuse large B-cell lymphoma and Hodgkin lymphoma, no data exist in follicular lymphoma. We describe survival outcomes according to pre-transplant PET status, classified by the Lugano criteria into complete metabolic remission (CMR) versus non-CMR, in 172 patients with relapsed or refractory follicular lymphoma within a national, multicenter, retrospective British Society of Blood and Marrow Transplantation and Cellular Therapy registry study. The median number of lines of therapy prior to SCT was three (range, 1-6). The median follow-up after SCT was 27 months (range, 3-70). The median progression-free survival for all patients after autoSCT was 28 months (interquartile range, 23- 36). There was no interaction between age at transplantation, sex, number of months since last relapse, Karnofsky performance status or comorbidity index and achieving CMR prior to autoSCT. Superior progression-free survival was observed in 115 (67%) patients obtaining CMR versus 57 (33%) non-CMR patients (3-year progression-free survival 50% vs. 22%, P=0.011) and by pre-SCT Deauville score (continuous variable 1-5, hazard ratio [HR]=1.32, P=0.049). PET status was independently associated with progression-free status (non-CMR HR=2.02, P=0.003), overall survival (non-CMR HR=3.08, P=0.010) and risk of relapse (non-CMR HR=1.64, P=0.046) after autoSCT by multivariable analysis. Our data suggest that pre- SCT PET status is of clear prognostic value and may help to improve the selection of patients for autoSCT.

Serum profiling identifies ibrutinib as a treatment option for young adults with B-cell acute lymphoblastic leukaemia.

Acute lymphoblastic leukaemia (ALL) is a haematological malignancy that is characterized by the uncontrolled proliferation of immature lymphocytes. 80% of cases occur in children where ALL is well understood and treated. However it has a devastating affects on adults, where multi-agent chemotherapy is the standard of care with allogeneic stem cell transplantation for those who are eligible. New treatments are required to extend remission and prevent relapse to improve patient survival rates. We used serum profiling to compare samples from presentation adult B-ALL patients with age- and sex-matched healthy volunteer (HV) sera and identified 69 differentially recognised antigens (P ≤ 0·02). BMX, DCTPP1 and VGLL4 showed no differences in transcription between patients and healthy donors but were each found to be present at higher levels in B-ALL patient samples than HVs by ICC. BMX plays a crucial role in the Bruton's Tyrosine Kinase (BTK) pathway which is bound by the BTK inhibitor, ibrutinib, suggesting adult B-ALL would also be a worthy target patient group for future clinical trials. We have shown the utility of proto-array analysis of B-ALL patient sera, predominantly from young adults, to help characterise the B-ALL immunome and identified a new target patient population for existing small molecule therapy.

New targets for therapy: antigen identification in adults with B-cell acute lymphoblastic leukaemia.

Acute lymphoblastic leukaemia (ALL) in adults is a rare and difficult-to-treat cancer that is characterised by excess lymphoblasts in the bone marrow. Although many patients achieve remission with chemotherapy, relapse rates are high and the associated impact on survival devastating. Most patients receive chemotherapy and for those whose overall fitness supports it, the most effective treatment to date is allogeneic stem cell transplant that can improve overall survival rates in part due to a 'graft-versus-leukaemia' effect. However, due to the rarity of this disease, and the availability of mature B-cell antigens on the cell surface, few new cancer antigens have been identified in adult B-ALL that could act as targets to remove residual disease in first remission or provide alternative targets for escape variants if and when current immunotherapy strategies fail. We have used RT-PCR analysis, literature searches, antibody-specific profiling and gene expression microarray analysis to identify and prioritise antigens as novel targets for the treatment of adult B-ALL.

Efficacy of venetoclax monotherapy in patients with relapsed chronic lymphocytic leukaemia in the post-BCR inhibitor setting: a UK wide analysis.

Venetoclax is a BCL2 inhibitor with activity in relapsed/refractory (R/R) chronic lymphocytic leukaemia (CLL). We conducted a multi-centre retrospective analysis of 105 R/R CLL patients who received venetoclax pre-National Health Service commissioning. The median age was 67 years and median prior lines was 3 (range: 1-15). 48% had TP53 disruption. At ≥2 lines, 60% received a Bruton Tyrosine Kinase inhibitor (BTKi) and no prior phosphoinositide 3-kinase inhibitor (Pi3Ki), 25% received a Pi3Ki and no prior BTKi, and 10% received both. Patients discontinued B cell receptor inhibitor (BCRi) because of toxicity in 44% and progression in 54%. Tumour lysis syndrome risk was low, intermediate or high in 27%, 25%, and 48% respectively. Overall response was 88% (30% complete response [CR]). The overall response rate was 85% (CR 23%) in BTKi-exposed patients, 92% (CR 38%) in Pi3Ki-exposed patients and 80% (CR 20%) in both (P = 0·59). With a median follow-up of 15·6 months, 1-year progression-free survival was 65·0% and 1-year overall survival was 75·1%. Dose reduction or temporary interruption did not result in an inferior progression-free or discontinuation-free survival. Risk of progression or death after stopping a prior BCRi for progression was double compared to those stopping for other reasons (predominantly toxicity) (Hazard Ratio 2·01 P = 0·05). Venetoclax is active and well tolerated in R/R CLL post ≥1 BCRi. Reason(s) for stopping BCRi influences venetoclax outcomes.

Mesenchymal stromal cells for acute graft-versus-host disease: response at 1 week predicts probability of survival.

Mesenchymal stromal cells (MSCs) have been successfully used for the treatment of steroid-resistant graft-versus-host-disease (GvHD). However, the lack of early predictors of clinical responses impacts on the time at which to add further treatment and consequently the design of informative clinical trials. Here, we present the UK experience of one of the largest cohorts of GvHD patients undergoing MSC infusions so far reported. We show that clinical responses assessed as early as 1 week after MSC infusion predict patients' overall survival. In our cohort, cell dose, patients' age and type of organ involvement are crucial factors associated with clinical responses.

Cyclophosphamide versus etoposide in combination with total body irradiation as conditioning regimen for adult patients with Ph-negative acute lymphoblastic leukemia undergoing allogeneic stem cell transplant: On behalf of the ALWP of the European Society for Blood and Marrow Transplantation.

Allogeneic hematopoietic cell transplantation (alloHCT) with myeloablative conditioning based on total body irradiation (TBI) is widely used for the treatment of adults with acute lymphoblastic leukemia (ALL). TBI is most frequently administered in combination with either cyclophosphamide (Cy/TBI) or etoposide (Vp/TBI). The goal of this study was to retrospectively compare these two regimens. Adult patients with Ph-negative ALL treated with alloHCT in first or second complete remission who received Cy/TBI (n = 1346) or Vp/TBI (n = 152) conditioning were included in the analysis. In a univariate analysis, as compared to Cy/TBI, the use of Vp/TBI was associated with reduced incidence of relapse (17% vs. 30% at 5 years, P = .007), increased rate of leukemia-free survival (60% vs. 50%, P = .04), and improved "graft versus host disease (GVHD) and relapse-free survival" (GRFS, 43% vs. 33%, P = .04). No significant effect could be observed in terms of the incidence of nonrelapse mortality or acute or chronic GVHD. In a multivariate model, the use of Vp/TBI was associated with reduced risk of relapse (HR = 0.62, P = .04) while the effect on other study end-points was not significant. In conclusion, conditioning regimen based on Vp combined with TBI appears more effective for disease control than the combination of Cy with TBI for adult patients with Ph-negative ALL treated with alloHCT.

Allogeneic haematopoietic stem cell transplantation for mitochondrial neurogastrointestinal encephalomyopathy.

Haematopoietic stem cell transplantation has been proposed as treatment for mitochondrial neurogastrointestinal encephalomyopathy, a rare fatal autosomal recessive disease due to TYMP mutations that result in thymidine phosphorylase deficiency. We conducted a retrospective analysis of all known patients suffering from mitochondrial neurogastrointestinal encephalomyopathy who underwent allogeneic haematopoietic stem cell transplantation between 2005 and 2011. Twenty-four patients, 11 males and 13 females, median age 25 years (range 10-41 years) treated with haematopoietic stem cell transplantation from related (n = 9) or unrelated donors (n = 15) in 15 institutions worldwide were analysed for outcome and its associated factors. Overall, 9 of 24 patients (37.5%) were alive at last follow-up with a median follow-up of these surviving patients of 1430 days. Deaths were attributed to transplant in nine (including two after a second transplant due to graft failure), and to mitochondrial neurogastrointestinal encephalomyopathy in six patients. Thymidine phosphorylase activity rose from undetectable to normal levels (median 697 nmol/h/mg protein, range 262-1285) in all survivors. Seven patients (29%) who were engrafted and living more than 2 years after transplantation, showed improvement of body mass index, gastrointestinal manifestations, and peripheral neuropathy. Univariate statistical analysis demonstrated that survival was associated with two defined pre-transplant characteristics: human leukocyte antigen match (10/10 versus <10/10) and disease characteristics (liver disease, history of gastrointestinal pseudo-obstruction or both). Allogeneic haematopoietic stem cell transplantation can restore thymidine phosphorylase enzyme function in patients with mitochondrial neurogastrointestinal encephalomyopathy and improve clinical manifestations of mitochondrial neurogastrointestinal encephalomyopathy in the long term. Allogeneic haematopoietic stem cell transplantation should be considered for selected patients with an optimal donor.

Idiotypic DNA vaccination for the treatment of multiple myeloma: safety and immunogenicity in a phase I clinical study.

We report on the safety and immunogenicity of idiotypic DNA vaccination in a phase I, non-randomised, open-label study in patients with multiple myeloma. The study used DNA fusion gene vaccines encoding patient-specific single chain variable fragment, or idiotype (Id), linked to fragment C (FrC) of tetanus toxin. Patients in complete or partial response following high-dose chemotherapy and autologous stem cell transplant were vaccinated intramuscularly with 1 mg DNA on six occasions, beginning at least 6 months post-transplant; follow-up was to week 52. Fourteen patients were enrolled on study and completed vaccinations. Idiotypic DNA vaccines were well tolerated with vaccine-related adverse events limited to low-grade constitutional symptoms. FrC- and Id-specific T-cell responses were detected by ex vivo ELISPOT in 9/14 and 3/14 patients, respectively. A boost of pre-existing anti-FrC antibody (Ab) was detected by ELISA in 8/14 patients, whilst anti-Id Ab was generated in 1/13 patients. Overall, four patients (29 %) made an immune response to FrC and Id, with six patients (43 %) responding to FrC alone. Over the 52-week study period, serum paraprotein was undetectable, decreased or remained stable for ten patients (71 %), whilst ongoing CR/PR was maintained for 11 patients (79 %). The median time to progression was 38.0 months for 13/14 patients. Overall survival was 64 % after a median follow-up of 85.6 months.

Efficient bone marrow irradiation and low uptake by non-haematological organs with an yttrium-90-anti-CD66 antibody prior to haematopoietic stem cell transplantation.

We report the results of a Phase I radiation dose escalation study using an yttrium-90 (90Y) labelled anti-CD66 monoclonal antibody given with standard conditioning regimen for patients receiving haematopoietic stem cell transplants for myeloid leukaemia or myeloma. The 90Y-labelled anti-CD66 was infused prior to standard conditioning. In total, 30 patients entered the trial and 29 received 90Y-labelled mAb, at infused radiation activity levels of 5, 10, 25, or 37.5 megaBequerel (MBq)/kg lean body weight. A prerequisite for receiving the 90Y-labelled mAb was favourable dosimetry determined by single-photon emission computerised tomography (SPECT) dosimetry following administration of indium-111 (111In) anti-CD66. Estimated absorbed radiation doses delivered to the red marrow demonstrated a linear relationship with the infused activity of 90Y-labelled mAb. At the highest activity level of 37.5 MBq/kg, mean estimated radiation doses for red marrow, liver, spleen, kidneys and lungs were 24.6 ± 5.6 Gy, 5.8 ± 2.7 Gy, 19.1 ± 8.0 Gy, 2.1 ± 1.1 and 2.2 ± 0.9, respectively. All patients engrafted, treatment-related mortality 1-year post-transplant was zero. Toxicities were no greater than those anticipated for similar conditioning regimens without targeted radiation. The ability to substantially intensify conditioning prior to haematopoietic stem cell transplantation without increasing toxicity warrants further testing to determine efficacy. clinicaltrials.gov identifier: NCT01521611.

Proteomic and phenotypic characteristics of memory-like natural killer cells for cancer immunotherapy.

BACKGROUND: Human and mouse natural killer (NK) cells have been shown to develop memory-like function after short-term exposure to the cocktail of IL-12/15/18 or to overnight co-culture with some tumor cell lines. The resulting cells retain enhanced lytic ability for up to 7 days as well as after cryopreservation, and memory-like NK cells (mlNK) have been shown to induce complete remissions in patients with hematological malignancies. No single phenotype has been described for mlNK and the physiological changes induced by the short-term cytokine or tumor-priming which are responsible for these enhanced functions have not been fully characterized. Here, we have generated mlNK by cytokine and tumor-priming to find commonalities to better define the nature of NK cell "memory" in vitro and, for the first time, in vivo. METHODS: We initiated mlNK in vitro from healthy donors with cytokines (initiated cytokine-induced memory-like (iCIML)-NK) and by tumor priming (TpNK) overnight and compared them by high-dimensional flow cytometry, proteomic and metabolomic profiling. As a potential mechanism of enhanced cytolytic function, we analyzed the avidity of binding of the mlNK to NK-resistant tumors (z-Movi). We generated TpNK from healthy donors and from cancer patients to determine whether mlNK generated by interaction with a single tumor type could enhance lytic activity. Finally, we used a replication-incompetent tumor cell line (INKmune) to treat patients with myeloid leukaemias to potentiate NK cell function in vivo. RESULTS: Tumor-primed mlNK from healthy donors and patients with cancer showed increased cytotoxicity against multiple tumor cell lines in vitro, analogous to iCIML-NK cells. Multidimensional cytometry identified distinct memory-like profiles of subsets of cells with memory-like characteristics; upregulation of CD57, CD69, CD25 and ICAM1. Proteomic profiling identified 41 proteins restricted to mlNK cells and we identified candidate molecules for the basis of NK memory which can explain how mlNK overcome inhibition by resistant tumors. Finally, of five patients with myelodysplastic syndrome or refractory acute myeloid leukemia treated with INKmune, three responded to treatment with measurable increases in NK lytic function and systemic cytokines. CONCLUSIONS: NK cell "memory" is a physiological state associated with resistance to MHC-mediated inhibition, increased metabolic function, mitochondrial fitness and avidity to NK-resistant target cells.

Immunogenicity of third dose COVID-19 vaccine strategies in patients who are immunocompromised with suboptimal immunity following two doses (OCTAVE-DUO): an open-label, multicentre, randomised, controlled, phase 3 trial.

BACKGROUND: The humoral and T-cell responses to booster COVID-19 vaccine types in multidisease immunocompromised individuals who do not generate adequate antibody responses to two COVID-19 vaccine doses, is not fully understood. The OCTAVE DUO trial aimed to determine the value of third vaccinations in a wide range of patients with primary and secondary immunodeficiencies. METHODS: OCTAVE-DUO was a prospective, open-label, multicentre, randomised, controlled, phase 3 trial investigating humoral and T-cell responses in patients who are immunocompromised following a third vaccine dose with BNT162b2 or mRNA-1273, and of NVX-CoV2373 for those with lymphoid malignancies. We recruited patients who were immunocompromised from 11 UK hospitals, aged at least 18 years, with previous sub-optimal responses to two doses of SARS-CoV-2 vaccine. Participants were randomly assigned 1:1 (1:1:1 for those with lymphoid malignancies), stratified by disease, previous vaccination type, and anti-spike antibody response following two doses. Individuals with lived experience of immune susceptibility were involved in the study design and implementation. The primary outcome was vaccine-specific immunity defined by anti-SARS-CoV-2 spike antibodies (Roche Diagnostics UK and Ireland, Burgess Hill, UK) and T-cell responses (Oxford Immunotec, Abingdon, UK) before and 21 days after the third vaccine dose analysed by a modified intention-to-treat analysis. The trial is registered with the ISRCTN registry, ISRCTN 15354495, and the EU Clinical Trials Register, EudraCT 2021-003632-87, and is complete. FINDINGS: Between Aug 4, 2021 and Mar 31, 2022, 804 participants across nine disease cohorts were randomly assigned to receive BNT162b2 (n=377), mRNA-1273 (n=374), or NVX-CoV2373 (n=53). 356 (45%) of 789 participants were women, 433 (55%) were men, and 659 (85%) of 775 were White. Anti-SARS-CoV-2 spike antibodies measured 21 days after the third vaccine dose were significantly higher than baseline pre-third dose titres in the modified intention-to-treat analysis (median 1384 arbitrary units [AU]/mL [IQR 4·3-7990·0] compared with median 11·5 AU/mL [0·4-63·1]; p<0·001). Of participants who were baseline low responders, 380 (90%) of 423 increased their antibody concentrations to more than 400 AU/mL. Conversely, 166 (54%) of 308 baseline non-responders had no response after the third dose. Detectable T-cell responses following the third vaccine dose were seen in 494 (80%) of 616 participants. There were 24 serious adverse events (BNT612b2 eight [33%] of 24, mRNA-1273 12 [50%], NVX-CoV2373 four [17%]), two (8%) of which were categorised as vaccine-related. There were seven deaths (1%) during the trial, none of which were vaccine-related. INTERPRETATION: A third vaccine dose improved the serological and T-cell response in the majority of patients who are immunocompromised. Individuals with chronic renal disease, lymphoid malignancy, on B-cell targeted therapies, or with no serological response after two vaccine doses are at higher risk of poor response to a third vaccine dose. FUNDING: Medical Research Council, Blood Cancer UK.

Use of a biosimilar granulocyte colony-stimulating factor for peripheral blood stem cell mobilization: an analysis of mobilization and engraftment.

Peripheral blood haematopoietic progenitor cell mobilization has become a standard procedure prior to autologous stem cell transplantation. Biosimilar granulocyte colony-stimulating factors (GCSF) have recently been awarded European Union (EU) licences for stem cell mobilization but data for their use in this context remain limited. The biosimilar GCSF, Ratiograstim(®) (Ratiopharm, Ulm, Germany) was granted an EU licence in September 2008 and incorporated into clinical practice in the Wessex Blood and Marrow Transplantation Programme in December 2008. Data were retrospectively collected for 154 consecutive patients undergoing peripheral blood stem cell harvest between January 2009 and December 2011 using the biosimilar GCSF. 131 consecutive patients from the preceding 3 years, who had received Neupogen(®) , were used as a control. We analysed both parameters relevant to stem cell collection and engraftment data, where patients proceeded to transplantation. We found no statistically significant difference between the two groups when comparing CD34 predictors, total number of CD34(+) stem cells collected, number of days required for collection, or for time to engraftment. This is, to our knowledge, the largest direct comparison of a biosimilar GCSF with originator GCSF for stem cell mobilization. The use of biosimilar GCSF can produce a significant cost saving, allowing investment in other areas of stem cell transplantation.

Comorbidities in transplant recipients with acute myeloid leukemia receiving low-intensity conditioning regimens: an ALWP EBMT study.

Older age and a high burden of comorbidities often drive the selection of low-intensity conditioning regimens in allogeneic hematopoietic stem cell transplantation recipients. However, the impact of comorbidities in the low-intensity conditioning setting is unclear. We sought to determine the contribution of individual comorbidities and their cumulative burden on the risk of nonrelapse mortality (NRM) among patients receiving low-intensity regimens. In a retrospective analysis of adults (≥18 years) who underwent transplantation for acute myeloid leukemia in the first complete remission between 2008 and 2018, we studied recipients of low-intensity regimens as defined by the transplantation conditioning intensity (TCI) scale. Multivariable Cox models were constructed to study associations of comorbidities with NRM. Comorbidities identified as putative risk factors in the low-TCI setting were included in combined multivariable regression models assessed for overall survival, NRM, and relapse. A total of 1663 patients with a median age of 61 years received low-TCI regimens. Cardiac comorbidity (including arrhythmia/valvular disease) and psychiatric disease were associated with increased NRM risk (hazard ratio [HR], 1.54; 95% confidence interval [CI], 1.13-2.09 and HR, 1.69; 95% CI, 1.02-2.82, respectively). Moderate pulmonary dysfunction, though prevalent, was not associated with increased NRM. In a combined model, cardiac, psychiatric, renal, and inflammatory bowel diseases were independently associated with adverse transplantation outcomes. These findings may inform patient and regimen selection and reinforce the need for further investigation of cardioprotective transplantation approaches.

An early post-transplant relapse prediction score in multiple myeloma: a large cohort study from the chronic malignancies working party of EBMT.

Early relapse (ER) following Autologous Hematopoietic Cell Transplantation (AHCT) confers a poor prognosis. We therefore developed a novel scoring system to predict ER. A total of 14,367 AHCT-1 patients were transplanted between 2014 and 2019, and were conditioned with Melphalan 200 mg/m2 (Mel200) (n = 7228; 2014-2017) (training cohort); Mel200 (n = 5616; 2018-2019) or Mel140 (n = 1523; 2018-2019) (validation cohorts). PFS-12 and the Cumulative Incidence of Relapse at 12 months were 84.1% and 14.7% (training Mel200), 87.2% and 11.6% (validation Mel200), and 80.3% and 16.9% (validation Mel140), respectively. The points in the risk score were: 0, 1,2 for ISS stages I, II, and III; Disease status: 0 (CR/VGPR); 1 (PR); 2 (SD/MR); 4 (Relapse/Progression); and 1 for Karnofsky ≤ 70. The distribution of scores: 0 (24%), 1 (33.9%), 2 (29.6 %), 3 (9.5%), and ≥4 (2.7%). The score separated PFS-12, with the lowest risk group (n = 1752) having a PFS-12 of 91.7% and the highest risk group (n = 195) 57.1%. This also applied in cytogenetically high-risk patients. If the pre-score baseline risks are 15% (standard risk) and 25% (high-risk), a score of ≥4 confers calculated risks of 38% and 54%, respectively. This novel EBMT ER score, therefore, allows for the identification of five discrete prognostic groups.

SARS-CoV-2-specific immune responses and clinical outcomes after COVID-19 vaccination in patients with immune-suppressive disease.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immune responses and infection outcomes were evaluated in 2,686 patients with varying immune-suppressive disease states after administration of two Coronavirus Disease 2019 (COVID-19) vaccines. Overall, 255 of 2,204 (12%) patients failed to develop anti-spike antibodies, with an additional 600 of 2,204 (27%) patients generating low levels (<380 AU ml-1). Vaccine failure rates were highest in ANCA-associated vasculitis on rituximab (21/29, 72%), hemodialysis on immunosuppressive therapy (6/30, 20%) and solid organ transplant recipients (20/81, 25% and 141/458, 31%). SARS-CoV-2-specific T cell responses were detected in 513 of 580 (88%) patients, with lower T cell magnitude or proportion in hemodialysis, allogeneic hematopoietic stem cell transplantation and liver transplant recipients (versus healthy controls). Humoral responses against Omicron (BA.1) were reduced, although cross-reactive T cell responses were sustained in all participants for whom these data were available. BNT162b2 was associated with higher antibody but lower cellular responses compared to ChAdOx1 nCoV-19 vaccination. We report 474 SARS-CoV-2 infection episodes, including 48 individuals with hospitalization or death from COVID-19. Decreased magnitude of both the serological and the T cell response was associated with severe COVID-19. Overall, we identified clinical phenotypes that may benefit from targeted COVID-19 therapeutic strategies.

Benchmarking of survival outcomes following Haematopoietic Stem Cell Transplantation (HSCT): an update of the ongoing project of the European Society for Blood and Marrow Transplantation (EBMT) and Joint Accreditation Committee of ISCT and EBMT (JACIE).

From 2016 EBMT and JACIE developed an international risk-adapted benchmarking program of haematopoietic stem cell transplant (HSCT) outcome to provide individual EBMT Centers with a means of quality-assuring the HSCT process and meeting FACT-JACIE accreditation requirements relating to 1-year survival outcomes. Informed by previous experience from Europe, North America and Australasia, the Clinical Outcomes Group (COG) established criteria for patient and Center selection, and a set of key clinical variables within a dedicated statistical model adapted to the capabilities of the EBMT Registry. The first phase of the project was launched in 2019 to test the acceptability of the benchmarking model through assessment of Centers' performance for 1-year data completeness and survival outcomes of autologous and allogeneic HSCT covering 2013-2016. A second phase was delivered in July 2021 covering 2015-2019 and including survival outcomes. Reports of individual Center performance were shared directly with local principal investigators and their responses were assimilated. The experience thus far has supported the feasibility, acceptability and reliability of the system as well as identifying its limitations. We provide a summary of experience and learning so far in this 'work in progress', as well as highlighting future challenges of delivering a modern, robust, data-complete, risk-adapted benchmarking program across new EBMT Registry systems.