Abstract: Background: Patients with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) often have a poor prognosis despite therapies using second-line chemoimmunotherapy (CIT). Achievement of complete response (CR) with second-line therapy is associated with improved long-term outcomes. Unfortunately, only 25-35% of patients achieve CR with standard CIT regimens alone. The addition of novel targeted agents such as Bruton Tyrosine Kinase inhibitors (BTKi) to second-line therapy may offer improved treatment responses given the importance of B-cell receptor (BCR) signaling in DLBCL. BTK has been shown to be essential for BCR-mediated activation of the NF- κB/Rel family of transcription factors and BCR signaling has been recognized as a key pathway in the pathogenesis of DLBCL. Moreover, NF-κB activity relies upon chronic active BCR signaling in activated B-cell-like DLBCL, which can be potentially blocked by kinase inhibitors targeting BTK. In this study we examine the feasibility and efficacy of adding the BTKi, acalabrutinib (A), to standard second-line therapy to improve disease response in patients with R/R DLBCL. Here we present initial safety and tolerability data for the ongoing study. Study Design and Methods: This is an open-label, prospective phase II trial (NCT03736616). Cohort A is open to R/R DLBCL patients eligible for autologous hematopoietic transplantation (HCT). Cohort B is open to R/R DLBCL patients considered ineligible for autologous HCT. The primary endpoint for cohort A is to estimate the confirmed CR rate (RECIL 2017 criteria) prior to autologous HCT in patients undergoing second-line CIT. The primary endpoint for cohort B is defined as the estimate of one-year progression-free survival in patients undergoing second-line induction and maintenance acalabrutinib therapy. Cohort A receive 2 cycles of standard RICE salvage CIT in combination with acalabrutinib, 100mg BID days 1-21 of a 21-day cycle (RICE+A). After 2 cycles of therapy, patients undergo autologous stem cell mobilization and collection. Patients then receive a 3 rd cycle of RICE in combination with acalabrutinib. PET-CT (PET3) is to be performed on day 15 of cycle 3 to assess response. Patients with CR or partial response (PR) after PET3 proceed to autologous HCT with BEAM conditioning within 28-42 days of PET3. Post-HCT CR patients receive acalabrutinib 100mg BID as maintenance therapy for 12 additional months. Protocol amendment in May 2021 allows for PET assessment (C2D15) prior to autologous stem cell collection (after cycle 3). Cohort B receive 3 cycles of RICE+A in 21-day cycles followed by PET-CT (PET3) on day 15 of cycle 3. Patients without progressive disease at PET3 continue with acalabrutinib maintenance up to 12 additional cycles until disease progression or unacceptable toxicity. Patients demonstrating progressive disease are withdrawn from study treatment but followed for outcomes. Results: Here we report initial safety and tolerability data for the ongoing study with data cutoff July 28, 2021. Twenty-two patients have been screened and 20 patients have received at least 1 cycle of RICE+A. Patient characteristics are shown in Table 1. Fifteen patients (79%) have completed 3 cycles of RICE+A. One patient (5%) discontinued due to an adverse event (AE; recurrent appendicitis), 3 patients (16%) discontinued due to progressive disease, and 1 patient is receiving ongoing RICE+A as of data cutoff. Hematologic AE have been observed in 17 patients (89%) with 74% being Grade 3/4. Amongst these, neutropenia was the most common AE occurring in 47% with all being Grade 3/4, and thrombocytopenia occurring in 32% with all being Grade 3/4. All hematologic AE recovered to baseline or grade 1 in median 7 days. Amongst non-hematologic AE, diarrhea occurred in 21% and 0% were Grade 3/4, nausea 16% with 0% Grade 3/4, and headache in 16% with 0% Grade 3/4. Discontinuation of therapy due to AE occurred in 1 patient (recurrent appendicitis) and dose reduction occurred in 1 patient (Gr 4 neutropenia). Temporary (per protocol) dose holds of A occurred in 9 patients (45%), primarily for cytopenias during concurrent RICE+A. Median duration for dose holds of A was 5.5 days. Conclusion: RICE+A is feasible with manageable primarily hematologic AEs similar to those reported for RICE alone. Enrollment and follow up is ongoing for efficacy endpoints and further toxicity assessment. Figure 1 Figure 1. Disclosures Bensinger: BMS, Janssen, Poseida, Regeneron, Trillium: Research Funding; Amgen, BMS, Janssen, Sanofi: Speakers Bureau. Glennie: Pharmacyclics/Janssen: Speakers Bureau. Pagel: Pharmacyclics/AbbVie: Consultancy; Incyte/MorphoSys: Consultancy; MEI Pharma: Consultancy; Gilead: Consultancy; Actinium Pharmaceuticals: Consultancy; AstraZeneca: Consultancy; BeiGene: Consultancy; Kite, a Gilead Company: Consultancy; Epizyme: Consultancy. Patel: Bristol Myers Squibb: Consultancy, Speakers Bureau; Janssen: Consultancy; Genentech: Consultancy; BeiGene: Consultancy; TG Therapeutics: Consultancy, Speakers Bureau; Abbvie: Consultancy; Pharmacyclics: Consultancy; Morphosys: Consultancy; Kite Pharma: Consultancy, Speakers Bureau; AstraZeneca: Consultancy, Research Funding, Speakers Bureau; MEI Pharma: Consultancy; ADC Therapeutics: Consultancy; Lilly: Consultancy. OffLabel Disclosure: Acalabrutinib is not FDA approved for treatment of DLBCL and is discussed in the context of an ongoing clinical trial only.

Abstract: Background: Patients with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) often have a poor prognosis despite therapies using second-line chemoimmunotherapy. Achievement of CR with second-line therapy is associated with improved long-term outcomes. Unfortunately, only 25-35% of patients achieve complete response (CR) with RICE chemotherapy alone. The addition of novel targeted agents such as Bruton Tyrosine Kinase inhibitors (BTKi) to second-line therapy may offer improved treatment responses given the importance of B-cell receptor (BCR) signaling in DLBCL. BTK has been shown to be essential for BCR-mediated activation of the NF- κB/Rel family of transcription factors and BCR signaling has been recognized as a key pathway in the pathogenesis of DLBCL. Moreover, NF-κB activity relies upon chronic active BCR signaling in activated B-cell-like DLBCL, which can be potentially blocked by kinase inhibitors targeting BTK. The goal of this study is to examine the feasibility and efficacy of adding the BTKi, acalabrutinib, to standard second-line therapy as a means to improve disease response. Establishing the feasibility of combining acalabrutinib with RICE chemotherapy in autologous hematopoietic cell transplantation (HCT) eligible and HCT ineligible patients with R/R DLBCL may provide the foundation for a larger study of efficacy and long-term outcomes of the combination therapy for patients with R/R DLBCL. Study Design and Methods: The primary objective of this phase 2 trial is to evaluate the tolerability, feasibility, and efficacy of combining acalabrutinib with RICE as second line therapy in R/R DLBCL patients. There are two study cohorts. Cohort A is open to R/R DLBCL patients who are eligible for autologous HCT. Cohort B is open to R/R DLBCL patients who are considered medically ineligible for autologous HCT. The primary endpoint for cohort A is to estimate the confirmed CR rate (RECIL 2017 criteria) prior to HCT in patients undergoing second-line therapy. The primary endpoint for cohort B is defined as the estimate of one-year progression-free survival in patients undergoing second-line induction and maintenance acalabrutinib therapy. Secondary endpoints include assessment of the proportion of patients completing 3 cycles of acalabrutinib with RICE and proceeding with HCT or 2 additional cycles of maintenance acalabrutinib for HCT ineligible patients, overall response rate, incidence of Grade 3/4 adverse events, and incidence of SAEs. Patients in cohort A receive 2 cycles of standard RICE salvage chemoimmunotherapy in combination with acalabrutinib, 100mg BID day 1-21 of a 21 day cycle. After 2 cycles of therapy, patients in cohort A undergo autologous stem cell mobilization and collection. Patients then receive a 3rd cycle of RICE in combination with acalabrutinib. PET-CT (PET3) is performed 14-21 days after day 1 of cycle 3 to assess response. Those patients with CR or partial response (PR) after PET3 proceed to autologous HCT with BEAM conditioning within 28-42 days of PET3. After adequate hematopoietic recovery, patients restart acalabrutinib 100mg BID as maintenance therapy for a period of 12 additional months. Patients in cohort B receive 3 cycles of RICE salvage chemoimmunotherapy in combination with acalabrutinib 100mg BID day 1-21 of a 21-day cycle followed by PET-CT (PET3) 14-21 days after start of Cycle 3. Patients without progressive disease at PET3 continue with acalabrutinib maintenance up to 12 additional cycles until disease progression or unacceptable toxicity. Patients demonstrating progressive disease are withdrawn from study treatment but their outcomes continue to be recorded and will be included in the final data analysis. Historical outcomes from completed, published prospective clinical trials using RICE chemoimmunotherapy serve as a reference for statistical calculations. This trial is currently ongoing and additional information can be found on clinicaltrials.gov NCT listing NCT03736616 Disclosures Bensinger: BMS: Consultancy, Honoraria, Research Funding, Speakers Bureau; Sanofi: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Amgen: Consultancy, Honoraria, Research Funding, Speakers Bureau; GSK: Consultancy, Honoraria, Research Funding, Speakers Bureau; Regeneron: Consultancy, Honoraria, Research Funding, Speakers Bureau. Mawad:Abbvie: Speakers Bureau; Adaptive Biotechnologies: Speakers Bureau. Glennie:Pharmacyclics: Speakers Bureau; Janssen: Speakers Bureau. Patel:Pharmacyclics: Consultancy, Speakers Bureau; Janssen: Consultancy, Speakers Bureau; Kite: Consultancy; AstraZeneca: Consultancy, Research Funding, Speakers Bureau; Adaptive Biotechnologies: Consultancy; Genentech: Consultancy, Speakers Bureau; Celgene/BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees; BeiGene: Consultancy. OffLabel Disclosure: Acalabrutinib is used an investigational agent for DLBCL in this study.

Abstract: Background : Central line associated blood stream infections (CLABSI) have been the costliest of all healthcare associated infections. The average CLABSI cost is approximately $46,000 (Haddadin & Regunath, 2019). Most cases may be preventable with utilization of aseptic techniques, surveillance, and management through local protocols. The majority of CLABSI occur more than five days after central vascular access (CVA); therefore, there has been a growing focus on central line handling and maintenance techniques. CLABSI prevention data has been largely focused on the intensive care unit (ICU) patient population where an average of about half of patients have CVA. There have been few studies exploring the rates of CLABSI in the adult hematology population, a population with unique risk factors due to their immunosuppressing treatments and prolonged immunocompromised states. There has been emerging data that suggests the use of new technology in addition to existing central line maintenance recommendations by the Center for Disease Control may further reduce the rate of CLABSI occurrences in high-risk patient populations. Aim: To determine the efficacy of passive valve antimicrobial swab caps on the reduction of CLABSI in an inpatient hematology patient population when compared to current existing local practices. Outcomes of reported incidents of CLABSI have been evaluated against pre-interventional data for this setting. Methods : Retrospective analysis of medical records from January 2016 - September 2019 identified the existing rate of CLABSI occurrence among inpatient hematology patients at a single institution. We utilized the intervention of antimicrobial swab caps for 10 months and tracked the rate of CLABSI during this time. The nursing staff were educated on the quality improvement project, the use of the new equipment, and expectations that existing standard practices per local policy for CLABSI prevention bundles would be adhered to prior to the start of the intervention. To evaluate the impact of the antimicrobial swab caps on the rate of CLABSI we compared the number of infections pre- and post-intervention. Randomized audits, including chart reviews for compliance with existing standard CLABSI bundle practices were performed during the initial 3 months of the intervention. Results : Prior to the introduction of the passive valve antimicrobial swab cap to the existing CLABSI prevention protocol, CLABSI rates on the hematology unit exceeded the standardized infection ratio 75th percentile on 9 of the previous 15 calendar quarters. The intervention was observed for 6,674 central line days. The CLABSI rate during the intervention was 0.4495 per 1,000 central line days. The CLABSIs identified were due to nosocomial opportunistic infection in setting of immunosuppressed status (66%) and gastrointestinal translocation (33%). The common diagnosis in setting of CLABSI was refractory/relapse diffuse large B-cell lymphoma (66%) and active acute myeloid leukemia (33%). The two patients who were diagnosed with CLABSI were neutropenic with an absolute neutrophil count of 0 at time of CLABSI diagnosis. The organisms identified at time of CLABSI diagnosis were Clostridium ramosom, Enterococcus faecium, Staphylococcus epidermisis, and Candida parapsilosis. When considering the cost of a CLABSI to be about $46,000 per event and the annual cost for the inpatient hematology unit's use of the caps of approximately $19,710, the implementation of the antimicrobial swab cap reduced the cost associated with CLASBI in the hematology unit by approximately $26,290 annually. Conclusions : The introduction of the passive valve antimicrobial swab caps appears to demonstrate potential for reduced costs due to CLABSI when implemented into current CLABSI prevention bundles. This resulted in a 25% reduction in rates of CLABSI in the adult hematology patient population when compared to the previous year. The prevention of CLABSI in hematology patients with central vascular access remains challenging, however, standardized protocols for CLABSI prevention and use of antimicrobial swab caps may help further reduce the rate of CLABSI in hematology patients. Disclosures: No relevant conflicts of interest to declare. Disclosures Glennie: Pharmacyclics: Speakers Bureau; Janssen: Speakers Bureau. Bensinger:BMS: Consultancy, Honoraria, Research Funding, Speakers Bureau; Sanofi: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Amgen: Consultancy, Honoraria, Research Funding, Speakers Bureau; GSK: Consultancy, Honoraria, Research Funding, Speakers Bureau; Regeneron: Consultancy, Honoraria, Research Funding, Speakers Bureau. Patel:Celgene/BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Speakers Bureau; AstraZeneca: Consultancy, Research Funding, Speakers Bureau; BeiGene: Consultancy; Adaptive Biotechnologies: Consultancy; Genentech: Consultancy, Speakers Bureau; Kite: Consultancy; Pharmacyclics: Consultancy, Speakers Bureau.

Abstract: Introduction: Patients with Diffuse large B-cell lymphoma (DLBCL) may experience excellent long-term outcomes after initial anthracycline containing therapy. However, patients with relapsed or refractory (R/R) DLBCL often have poor outcomes. Select R/R DLBCL patients may be treated with additional chemoimmunotherapy (CIT) followed by hematopoietic stem cell transplant (HSCT). However, as many as 50% of R/R DLBCL patients are unable to undergo HSCT due to lack of response to CIT or comorbidities (Gisselbrecht C, et al JCO 2010). Recent data reported in the SCHOLAR-1 study suggest a median overall survival (OS) of 6.3 months for these patients, with only 20% of patients alive at 2 years (Crump M, et al Blood 2017). Chimeric antigen receptor T-cell (CAR-T) therapy, a novel form of immunotherapy, offers improved outcomes for such patients with complete response rates of approximately 40% and 50% OS at 12 months or greater (Neelapu SS et al. NEJM 2017; Borchmann P et al, EHA 2018). Delivery of CAR-T therapy is specialized and remains limited to a small number of centers at present. The broad applicability of CAR-T therapy in a real world population of R/R DLBCL patients remains unknown. This retrospective study aimed to identify the characteristics and outcomes of a cohort of R/R DLBCL patients who would have been eligible for CAR-T cell therapy if available over a 4 year period at Swedish Cancer Institute (SCI). The SCI is a specialty cancer research center, based in a non-profit, non-university affiliated medical center. Methods: All patients with recorded diagnosis of DLBCL (ICD9/10) seen for an outpatient encounter in a SCI facility between the dates of 01/01/2014 and 01/01/2018 were identified from an electronic medical record database. Patients who had received anthracycline-based chemotherapy only at SCI as initial therapy and then subsequently received 2nd line or beyond therapy at SCI between January 2014 and January 2018 were included. This population was defined as the study cohort of R/R DLBCL patients and was then evaluated for would-be eligibility for CAR-T therapy by application of the defined Kite Zuma-1 clinical trial Inclusion/Exclusion (I/E) criteria. Patient characteristics for the CAR-T eligible population were obtained by retrospective medical record review. Overall survival of the potential CAR-T eligible population was assessed including stratification by receipt of HSCT at any time during the study period. Results: 486 patients with a diagnosis of DLBCL were seen during outpatient SCI encounters between Jan 2014 and Jan 2018. Of these, 60 patients received prior 1st line anthracycline therapy exclusively at SCI and then received 2nd line or beyond therapy at SCI between 2014 and 2018 for R/R DLBCL. The majority of patients, 82% (n=49), met all Zuma-1 I/E criteria for CAR-T therapy. Characteristics of these patients are identified in Table 1. Among all CAR-T eligible patients, OS was 37.1% at 24 months (Figure 1). Patients received a variety of 2nd line or beyond therapies, including 47% (n=23) who received HSCT. OS at 24 months for CAR-T eligible patients was significantly better for those receiving HSCT in 2nd line or beyond versus those who did not receive HSCT (61.6% vs 12.0%, respectively; p 〈 0.001; Figure 2). Conclusion: In a retrospective cohort of real-world R/R DLBCL patients treated between 2014 and 2018 at SCI, a non-university based specialty cancer research center, 49 of 60 patients (82%) would have been eligible for CAR-T therapy based on Zuma 1 I/E criteria. This suggests that the majority of the patients with R/R DLBCL in the real-world may have an opportunity to receive CAR-T. Moreover, while those who underwent a successful HSCT as part of 2nd line or beyond therapy had greatly improved outcomes, those patients who did not undergo HSCT had poor outcomes. For such patients not receiving HSCT, the availability of CAR -T may lead to significantly improved outcomes. Disclosures Pagel: Pharmacyclics, an AbbVie Company: Consultancy; Gilead: Consultancy. Bensinger:Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; amgen: Speakers Bureau; Takeda: Speakers Bureau; celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Mawad:Swedish Cancer Institute: Employment. Patel:Pharmacyclics/Janssen: Speakers Bureau; Sunesis Pharmaceuticals: Consultancy; AstraZeneca: Consultancy, Research Funding, Speakers Bureau; Genentech: Consultancy, Speakers Bureau; Celgene: Consultancy; Juno Therapeutics: Consultancy.