Abstract: The ZAP-70 tyrosine kinase plays a critical role in signal transduction in T cells and NK cells but has limited expression in primary human B cells. However ZAP-70 is expressed in many cases of B cell chronic lymphocytic leukemia and correlates with a poor prognosis. Microarray analysis has recently identified ZAP-70 expression in a range of other B cell malignancies, including acute lymphoblastic leukaemia (ALL), and ZAP-70 expression may carry prognostic value in these diseases. Microarray analysis may not offer the most accurate method for quantitation of small changes in mRNA expression and this technology may therefore limit the potential information to be derived from ZAP-70 expression. We developed a real time quantitative PCR assay for ZAP-70 and used this to determine ZAP-70 expression in 76 adult patients with ALL (64 B lineage and 12 T lineage). RNA was extracted from diagnostic bone marrow specimens taken from 76 patients aged over 18 years presenting with ALL. Quantitative PCR was optimised using Jurkat T cells and utilized GAPDH as the internal control. ZAP-70 and GAPDH cDNA were co-amplified in a multiplex PCR reaction with five-fold serial dilutions of Jurkat cDNA ranging from 25ng to 40pg, and this data was used to construct the calibration curve. ZAP-70 expression within tumours was determined relative to expression within the T cell line Jurkat, defined as having an arbitrary value of 1.0. A wide distribution of ZAP-70 expression was seen in individual ALL cases with a range between 0.002 and 5.3. The average ZAP-70 expression level within ALL was below that of Jurkat with a mean of 0.332 and median of 0.185. Expression of ZAP-70 showed a relatively continuous pattern of expression across the cohort apart from six samples (8%) with a level of ZAP-70 expression above that of the Jurkat T cell line. Statistical analysis of a potential association between ZAP-70 expression and cytogenetic subgroup was performed by group comparison using either a two-sample test or ANOVA. No significant association between ZAP-70 expression and cytogenetic subgroup was found. Only 4 cases of t(1,19) translocation encoding the E2A/PBX1 gene fusion were seen in the cohort and all had ZAP-70 levels above the median level. Within the T-ALL subgroup, 11 of the 12 patients showed ZAP-70 expression above the median with a mean of 0.26. Low expression was observed in 4 of the 5 cases in the b3a2/b2a2 p210 BCR/ABL subgroup. Study of a potential correlation between ZAP-70 expression and clinical prognosis is continuing but the three patients with the highest levels of ZAP-70 failed to achieve remission with induction therapy and died of refractory disease. These data confirm that ZAP-70 expression is seen in the majority of cases of ALL and demonstrate the wide range of expression between individual cases. Large cohort studies are likely to be required to confirm an association between ZAP-70 expression and specific cytogenetic subgroup and to confirm the potential prognostic value of ZAP 70 expression.

Abstract: Introduction: Daratumumab in combination with bortezomib and dexamethasone (DVd) demonstrated a superior overall response rates (ORR) and progression free survival (PFS) compared to Vd in the CASTOR phase 3 trial for patients with RRMM. On this basis, DVd was recommended in March 2019 for UK patients with RRMM that had 1 prior line (PL). Discrepancies in outcomes between patients treated in clinical trials compared to routine practice is well recognised due to a combination of patient, disease and treatment-related factors. In addition, bortezomib is often administered once-weekly in routine practice to minimise neuropathy, while CASTOR used bi-weekly bortezomib dosing. As a result, the real-world outcomes of patients treated with DVd are yet to be determined. The primary aims of this analysis was to assess the ORR and PFS for patients with RRMM with 1PL treated with DVd in routine practice. Secondary aims were to assess OS, time to next treatment (TTNT), and efficacy in different sub-groups (high risk cytogenetics, previous proteasome inhibitor (PI) exposure, refractoriness of prior therapies, bi-weekly vs weekly bortezomib schedule, and previous treatment free interval (TFI)). Methods: This was a retrospective analysis from 14 centres (academic and community hospitals; 7 within the West Midlands Research Consortium (WMRC)) treated with DVd between March 2019 and June 2021. Patients received daratumumab (IV and then SC from June 2020) weekly in cycles 1-3, on day 1 of a 3-week cycle during cycles 4-8, and then monthly from cycle 9 to progression. SC Bortezomib was predominantly given weekly for cycles 1-8 although 5 centres used bi-weekly dosing for selected patients with aggressive disease. Adverse events were graded as per CTCAE criteria. Results: 288 patients were included, with a median age of 69 years (range 20-88) (Table 1). Patients received a median of 1 PL (range 1-2) with 93% (269) 1PL, 7% (18) 2 PL (due to COVID-19 measures). The majority had an ECOG performance status of 0-2 (98%) and most received weekly bortezomib (n=201). This population differed from those with 1PL treated on CASTOR in being older, more were ISS 3 (31% vs 19%, p=0.0145), and more had prior bortezomib exposure (71% vs 51%, p=0.0003), 4% were PI refractory, 9% had a GFR of & lt;30ml/min ( & lt;20ml/min was an exclusion from CASTOR), and 2% had an ECOG performance status of ≥3. The ORR was 76%, with & gt;VGPR in 54% (Table 2), with no significant difference in response between patients receiving biweekly vs weekly bortezomib (85% vs 83%; p=0.71). The median time to response was 1.6m. With a median follow up of 15m, the median PFS was 14m (95% CI 11.6-16). High cytogenetic risk patients had inferior outcomes: median PFS 10m (95% CI 6-14) for high risk vs not reached for standard risk (p=0.043); as did those with advanced ISS: median PFS was not reached, 15 and 12m for stage I, II and III respectively (p=0.05). For 15 patients with extramedullary disease (EMD), the median PFS was 3m (95% CI 1-5). Median PFS for patients who were PI refractory was shorter (10m vs 15m for PI sensitive patients (p=0.006)). There was no difference in median PFS for patients with prior PI exposure vs no prior PI (15 vs 13m; p=0.75), or according to weekly or bi-weekly bortezomib schedule (11 vs 15m; p=0.14). The median TTNT was 21m (95% CI 17-25). Overall, the median duration of treatment was 8m and 25 patients (9%) stopped treatment to receive a second autologous stem cell transplant. Those that had a prior TFI of & gt;12m had a longer median PFS of 21m vs 10m (p=0.0004). The median OS has not been reached, with an estimated 2-year OS of 74%. For patients with high risk cytogenetics the median OS was 16m (95% CI 9-23; vs not reached for standard risk; p=0.0006), with estimated 2-year OS in the high risk group of 36%. There was no difference in OS for patients treated with biweekly vs weekly bortezomib (not reached for either; p=0.38). DVd was generally well tolerated with 6% stopping due to adverse events (CASTOR 9.5%). Grade 3 or 4 toxicity occurred in 62 (22%) most commonly neutropenia and thrombocytopenia, with any grade infusion reactions reported in 27 (9%). Conclusions: These real-world data of DVd at 1 st relapse demonstrated good tolerability and high response rates with a weekly bortezomib schedule despite a more heterogenous population. However, high risk patients by cytogenetics, ISS or EMD had inferior outcomes as did those treated within 12 months from first line treatment. Figure 1 Figure 1. Disclosures Cook: Karyopharm: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria; Takeda: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding; BMS: Consultancy, Honoraria, Research Funding; Oncopeptides: Consultancy, Honoraria; Roche: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Research Funding. Pratt: Binding Site: Consultancy; BMS/Celgene: Consultancy; Gilead: Consultancy; Janssen: Consultancy; Takeda: Consultancy; Amgen: Consultancy. Kishore: Celgene: Other: Attending fees; Jannsen: Other: Attending fees; Sanofi: Other: Attending fees; Takeda: Other: Attending fees. Yong: Amgen: Honoraria; Autolus: Research Funding; BMS: Research Funding; Janssen: Honoraria, Research Funding; Sanofi: Honoraria, Research Funding; GSK: Honoraria; Takeda: Honoraria. Popat: Abbvie, Takeda, Janssen, and Celgene: Consultancy; Takeda: Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES; GlaxoSmithKline: Consultancy, Honoraria, Research Funding; AbbVie, BMS, Janssen, Oncopeptides, and Amgen: Honoraria; Janssen and BMS: Other: travel expenses.

Abstract: Immune suppression is a clinical feature of chronic lymphocytic leukaemia (CLL), and patients show increased vulnerability to SARS-CoV-2 infection and suboptimal antibody responses. Method We studied antibody responses in 500 patients following dual COVID-19 vaccination to assess the magnitude, correlates of response, stability and functional activity of the spike-specific antibody response with two different vaccine platforms. Results Spike-specific seroconversion post-vaccine was seen in 67% of patients compared to 100% of age-matched controls. Amongst responders, titres were 3.7 times lower than the control group. Antibody responses showed a 33% fall over the next 4 months. The use of an mRNA ( n  = 204) or adenovirus-based ( n  = 296) vaccine platform did not impact on antibody response. Male gender, BTKi therapy, prophylactic antibiotics use and low serum IgA/IgM were predictive of failure to respond. Antibody responses after CD20-targeted immunotherapy recovered 12 months post treatment. Post-vaccine sera from CLL patients with Spike-specific antibody response showed markedly reduced neutralisation of the SARS-CoV-2 delta variant compared to healthy controls. Patients with previous natural SARS-CoV-2 infection showed equivalent antibody levels and function as healthy donors after vaccination. Conclusions These findings demonstrate impaired antibody responses following dual COVID-19 vaccination in patients with CLL and further define patient risk groups. Furthermore, humoural protection against the globally dominant delta variant is markedly impaired in CLL patients and indicates the need for further optimisation of immune protection in this patient cohort.

Abstract: Although factors such as age, sex, diabetes, obesity and changes in certain laboratory investigations are important prognostic factors in COVID‐19 infection, these may not apply to all ethnic/racial groups. We hypothesized differences in routine biochemistry and haematology indices in Caucasian and a combined group of Black, Asian and Minority Ethnic (BAME) patients who tested positive for COVID‐19 who died, compared to survivors. Methods We tested our hypothesis in 445 patients (229 Caucasian, 216 BAME) admitted to secondary care with proven COVID‐19 infection, in whom standard routine laboratory indices were collected on admission. Results After 28 weeks, 190 (42.7%) had died within 28 days of COVID diagnosis (97 Caucasians [42.4%], 93 BAMEs [43.1%] , P  = .923). A general linear model analysis found the ethnicity interaction with mortality to be significant for fibrinogen, ferritin and HbA 1 c (after controlling for age). In a multivariate analysis, a neutrophil/lymphocyte ratio  〉  7.4 and a urea/albumin ratio  〉  0.28 increased the odds of death for both the Caucasian and the BAME group. Additional factors increasing the odds ratio in the BAME group included age 〉 60 years and being diabetic. Conclusion Neutrophil/lymphocyte ratio and urea/albumin ratio are simple metrics that predict death to aid clinicians in determining the prognosis of COVID‐19 and help provide early intensive intervention to reduce mortality. In the BAME groups, intensive monitoring even at younger age and those with diabetes may also help reduce COVID‐19 associated mortality.

Abstract: Management of chronic myeloid leukaemia (CML) has recently undergone dramatic changes, prompting the European LeukemiaNet (ELN) to issue recommendations in 2013; however, it remains unclear whether real‐world CML management is consistent with these goals. We report results of UK TARGET CML, a retrospective observational study of 257 patients with chronic‐phase CML who had been prescribed a first‐line TKI between 2013 and 2017, most of whom received first‐line imatinib ( n  = 203). Although 44% of patients required ≥1 change of TKI, these real‐world data revealed that molecular assessments were frequently missed, 23% of patients with ELN‐defined treatment failure did not switch TKI, and kinase domain mutation analysis was performed in only 49% of patients who switched TKI for resistance. Major molecular response (MMR; BCR‐ABL1 IS ≤0·1%) and deep molecular response (DMR; BCR‐ABL1 IS ≤0·01%) were observed in 50% and 29%, respectively, of patients treated with first‐line imatinib, and 63% and 54%, respectively, receiving a second‐generation TKI first line. MMR and DMR were also observed in 77% and 44% of evaluable patients with ≥13 months follow‐up, receiving a second‐generation TKI second line. We found little evidence that cardiovascular risk factors were considered during TKI management. These findings highlight key areas for improvement in providing optimal care to patients with CML.

Abstract: Limited data exist on COVID‐19 vaccination efficacy in patients with acute myeloid leukemia and myelodysplasia with excess blasts (AML/MDS‐EB2). We report results from a prospective study, PACE (Patients with AML and COVID‐19 Epidemiology). 93 patients provided samples post‐vaccine 2 or 3 (PV2, PV3). Antibodies against SARS‐COV‐2 spike antigen were detectable in all samples. Neutralization of the omicron variant was poorer than ancestral variants but improved PV3. In contrast, adequate T‐cell reactivity to SARS‐COV‐2 spike protein was seen in only 16/47 (34%) patients PV2 and 23/52 (44%) PV3. Using regression models, disease response (not in CR/Cri), and increasing age predicted poor T cell response.

Abstract: The impact of Coronavirus disease 2019 (COVID-19) on outcomes in patients with cancer remains unclear. Acute Myeloid Leukemia (AML)/high-risk myelodysplasia (MDS) are common hematological malignancies resulting in profound immunosuppression, which is exacerbated by intensive and less-intensive chemotherapy. Importantly, venetoclax based regimens have been increasingly used during the pandemic as a strategy to reduce patient hospitalization however, there is little information concerning the impact of such regimens on COVID-19 infection rates. We therefore opened a prospective clinical study (PACE), at the start of the current pandemic in April 2020 to characterize the risk of COVID-19 infection in patients with AML/MDS-EB2 receiving intensive or non-intensive treatment, including patients treated with venetoclax-based regimens. The primary aim was to determine the incidence of COVID-19 in patients with AML /MDS-EB2 including both, prior to study entry and during treatment until 4 weeks after the last cycle of treatment. Secondary aims were to: characterize the presentation of COVID-19; define the severity and type of both non-COVID-19 and COVID-19 infections; and undertake an exploratory analysis to quantify the incidence of COVID-19 infection in patients receiving (less-intensive) venetoclax based regimens. All analysis conducted to date has been descriptive. 211/230 recruited patients had full treatment histories available, of whom 116 patients received intensive chemotherapy and 95 low intensity regimens. 48 patients received a venetoclax-based regimen. The median age of the non-intensive treatment arm was 72 years; (range 19.1-86.5) and of the intensive arm was 59 years (range 16.1-76.1). There were more cases of secondary AML and relapsed disease in the non-intensive arm as compared to the intensive arm. 25/226 evaluable patients tested positive for COVID-19 as defined by positive SARS-CoV2 PCR test, 10 with a prior diagnosis at study entry and 15 tested positive during the study. The incidence of COVID-19 infection for patients with AML/MDS-EB2 was 11.1% (90%CI: 7.8%-15.1%) (Table). A lower proportion of patients (n=6/91 6.6%) undergoing non-intensive treatment suffered COVID-19 as compared to those undergoing more intensive chemotherapy regimens (n=19/116, 16.4%). Specifically, only 3/48 (6.3%) patients undergoing a venetoclax regimen were infected with SARS-CoV2. The most common presenting symptoms of COVID-19 in this study, regardless of the intensity of chemotherapy, was fever and cough with 6/25 patients asymptomatic. The risk of death at 30 days following study entry in patients who had prior COVID-19 infection or who contracted COVID-19 during this period was 13.6%, compared to 3.9% in the overall cohort without COVID-19 infection. There was a lower incidence of non-COVID-19 related infections in patients receiving venetoclax-based regimens, n=43 infections in 24 (50.0%) of patients; with 313 infections in 94 (81%) of intensively treated patients. The overall occurrence of non-COVID-19 infection in the non-intensive arm was 87 infections in 50 (54.9%) patients. Our multi-center study provides real-world estimates for the incidence and presentation of COVID-19 infection in a cohort of patients with AML/MDS-EB2, and indicates a higher risk of death at 30 days in patients with prior COVID-19 infection prior to, or during treatment. Venetoclax based, and other non-intensive, regimens, increasingly implemented during the pandemic, to minimize patient exposure and reduce usage of hospital beds, appeared to be associated with a low incidence of COVID-19. Further follow-up will be required to understand the long-term impact of this strategy. Analysis of immune responses to COVID-19 infection and vaccination is on-going. Acknowledgments: This study was funded by Cure Leukaemia under the Trials Acceleration Program (TAP), and grants from BMS and Blood Cancer UK. Figure 1 Figure 1. Disclosures Loke: Novartis: Other: Travel; Janssen: Honoraria; Amgen: Honoraria; Pfizer: Honoraria; Daichi Sankyo: Other: Travel. Knapper: Pfizer: Consultancy, Speakers Bureau; Astellas: Ended employment in the past 24 months, Speakers Bureau; Jazz: Consultancy, Speakers Bureau; Novartis: Consultancy, Research Funding, Speakers Bureau. Khan: Abbvie: Honoraria; Astellas: Honoraria; Takeda: Honoraria; Jazz: Honoraria; Gilead: Honoraria; Novartis: Honoraria. Dillon: Amgen: Other: Research support (paid to institution); Astellas: Consultancy, Other: Educational Events , Speakers Bureau; Menarini: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees, Other: Session chair (paid to institution), Speakers Bureau; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: educational events; Jazz: Other: Education events; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Research Support, Educational Events; Shattuck Labs: Membership on an entity's Board of Directors or advisory committees. Culligan: AbbVie Ltd: Honoraria, Speakers Bureau; Celgene Ltd: Honoraria, Speakers Bureau; Gilead: Honoraria, Speakers Bureau; Jazz Pharma: Honoraria, Speakers Bureau; Takeda UK Ltd: Honoraria, Speakers Bureau. McMullin: Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees, Other: clinical trial support, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AbbVie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AOP Orphan: Research Funding, Speakers Bureau. Murthy: Abbvie: Other: support to attend educational conferences.. Craddock: Novartis Pharmaceuticals: Other: Advisory Board ; Celgene/BMS: Membership on an entity's Board of Directors or advisory committees, Research Funding.