Kraft, Robert M.

Abstract Primary cutaneous diffuse large B‐cell lymphoma, leg type (PCDLBCL, LT) is a rare, aggressive lymphoma characterized by skin involvement predominantly in the lower extremities. Immunochemotherapy with or without involved‐site radiation therapy (ISRT) is considered standard front‐line therapy. Over‐expression of PD‐L1/PD‐L2 is seen in a high proportion of PCDLBCL, LT cases, but efficacy of immune checkpoint inhibitors (ICI) in relapsed/refractory, PCDLBCL, LT has not been thoroughly studied. We conducted a retrospective cohort study of patients diagnosed with PCDLBCL, LT seen at Mayo Clinic from 1 January 2000 to 31 December 2020. Using the Kaplan–Meier method, we calculated progression‐free survival, duration of response, and overall survival in patients who received front‐line rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R‐CHOP) with and without ISRT, and salvage ICI therapy for relapsed/refractory disease. A total of 28 patients with PCDLBCL, LT were identified. The median PFS in patients treated with R‐CHOP plus ISRT was 58 months (95% CI: 18–112) compared to 14 months (95% CI: 5–not reached; p = 0.04) in those treated with R‐CHOP without ISRT. The median PFS from salvage ICI therapy was 10 months (95% CI: 4–not reached), and median DOR from salvage ICI therapy was 23 months [95% CI: 4–26]. R‐CHOP with ISRT had a significantly longer median PFS compared to R‐CHOP without ISRT as front‐line therapy for PCDLBCL, LT. ICIs may have a role in treating relapsed/refractory disease as reasonable activity in heavily pre‐treated patients was observed in this study.

e19547 Background: Primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL, LT) is a rare, aggressive lymphoma characterized by skin involvement predominantly in the lower extremities, and is associated with an inferior prognosis compared to other primary cutaneous B-cell lymphomas. Immunochemotherapy with or without involved-field radiation therapy (IFRT) is considered standard, front-line therapy. Interestingly, over-expression of PD-L1/PD-L2 has been shown in a high proportion of PCDLBCL, LT cases, but efficacy of immune checkpoint inhibitors (ICI) in relapsed/refractory, PCDLBCL, LT has not been thoroughly studied. Therefore, we describe the outcomes of 1) immunochemotherapy with and without IFRT as front-line treatment of PCDLBCL, LT, and 2) ICIs in the relapsed/refractory setting. Methods: We conducted a retrospective cohort study of patients diagnosed with PCDLBCL, LT seen at Mayo Clinic from January 1, 2000 to December 31, 2020. Using the Kaplan-Meier method, we calculated progression-free survival (PFS), duration of response (DOR), and overall survival (OS) in patients who received front-line R-CHOP with and without IFRT, and salvage ICI therapy for relapsed/refractory disease. Results: A total of 28 patients with PCDLBCL, LT were identified. The median age at diagnosis was 71.6 years (range 48.0-91.7), 50% (N = 14) were male, and 78.6% (N = 22) had disease involvement of the lower extremities at diagnosis. For front-line treatment, 31.2% (N = 9) received R-CHOP with IFRT, and 31.2% (N = 9) received R-CHOP without IFRT. The median PFS in patients treated with R-CHOP plus IFRT was 41.8 months [95% CI: 30.2-69.6] compared to 13.7 months [95% CI: 10.7-27.7; p= 0.01] in those treated with R-CHOP without IFRT. The median OS in patients treated with R-CHOP plus IFRT was 74.7 months [95% CI: 53.0-108.6] compared to 38.2 months [95% CI: 26.0-80.4; p= 0.14] in those treated with R-CHOP without IFRT. Patient and disease characteristics were similar among these two groups. ICIs were used in 17.9% (N = 5) of patients with relapsed/refractory, PCDLBCL, LT, and these patients had received a median of three (range 2-10) prior systemic therapies. The overall response rate was 60% as three patients treated with ICIs achieved a complete response, and the other two patients showed no clinical response. The median DOR from ICIs was 23.0 months [95% CI: 3.6-26.0]. The median PFS from ICI therapy was 10.2 months [95% CI: 3.6 – not reached]. Only one of the five patients was noted to have a mild side effect from ICI treatment (elevated alkaline phosphatase, grade 1). Conclusions: R-CHOP with IFRT was associated with a longer median PFS compared to R-CHOP without IFRT as front-line therapy for PCDLBCL, LT. Furthermore, ICIs may have a role in treating relapsed/refractory disease as reasonable activity in heavily pre-treated patients and a favorable safety profile were observed in this study. Further studies would be of benefit to confirm our findings.

Background: Aggressive lymphomas are potentially curable; however, long-term effects of treatment and the disease may adversely affect patients' quality of life (QoL). We investigated QoL at baseline, and up to nine years after diagnosis in survivors of aggressive lymphomas. Methods: Patients newly diagnosed with lymphoma were prospectively enrolled within nine months of diagnosis in the Molecular Epidemiology Resource (MER) of the University of Iowa/Mayo Clinic Lymphoma Specialized Program of Research Excellence (SPORE) and systematically followed. Patients were enrolled from September 1, 2002 until June 30, 2015. Eligibility criteria included being a United States resident, English-speaking, no history of HIV, and aged 18 years and older. All pathology was reviewed by a lymphoma hematopathologist. Aggressive lymphoma subtypes included in this analysis were diffuse large B-cell lymphoma (DLBCL), Follicular lymphoma grade III, Hodgkin lymphoma, T-cell lymphoma, other non-Hodgkin lymphoma not otherwise specified (NOS), other B-cell lymphoma NOS, and composite lymphomas. We assessed QoL using the Functional Assessment of Cancer Therapy-General (FACT-G) scale at baseline enrollment, and 1, 2, 3, 6, and 9 years post-diagnosis. FACT-G measures well-being (WB) in four domains-physical (PWB), social/family (SFWB), emotional (EWB), and functional (FWB), which are added to create a total (TOT) score. Those who completed <80% of FACT-G questions at any given time point were excluded. "Survivor" was defined as alive at 1, 2, 3, 6, and 9 year follow-up with no active disease or treatment within six months of a given time point. Because patients could be enrolled at any time within the first 9 months from diagnosis, the timing of initial QoL assessment was variable with respect to the start of lymphoma treatment. We estimated longitudinal change in QoL using mixed models incorporating scores from all available time points. The minimally important difference (MID) of 5 points for TOT and 2 points for each of the domains was used to determine clinical significance. Scores were compared to United States (US) general population normative data. All statistical analyses were performed using SAS (v 9.4). Results: From September 1, 2002 to June 30, 2015, 3,028 patients with aggressive lymphomas were prospectively enrolled in the MER, of which 2,018 completed the FACT-G baseline assessment (47% prior to therapy initiation). Of these patients, 1,144 at 1 year, 1,002 at 2 years, 943 at 3 years, 562 at 6 years, and 289 at 9 years post-diagnosis completed the FACT-G at both baseline and each of the respective time points after diagnosis, and met the definition of survivor. The median age at diagnosis of patients analyzed was 59 years (range 18-93). The cohort included 844 female patients (42%). DLBCL comprised 44% of cases, Hodgkin lymphoma 19%, T-cell lymphoma 11%, composite lymphomas 8%, other B-cell NOS 6%, other non-Hodgkin lymphoma NOS 7%, and Follicular lymphoma grade III 5%. QoL increased from baseline enrollment; the largest increase was seen from baseline to 1 year after diagnosis with a statistically and clinically significant mean TOT score difference of 6.7 points. This mean increase in TOT scores sustained over time with an increase of 7.8 points above baseline at 9 years after diagnosis. At baseline, PWB, EWB, and FWB scores were significantly lower in patients with aggressive lymphomas compared to the US general population, and SFWB scores were significantly higher (all p <0.01); however, only SFWB and EWB score differences were clinically significant as defined by MID. SFWB showed only a mild decline from baseline over the course of 9 years. Despite this, all SFWB scores were statistically and clinically significantly higher than the US general population at 1, 2, 3, 6, and 9 years after diagnosis (all p <0.01 and MID >2). Patients with aggressive lymphomas TOT scores at baseline did not differ from the US general population, while TOT scores at 1, 2, 3, 6, and 9 years post-diagnosis were statistically and clinically significantly higher. Overall, the results in the pre-treatment QoL subset were consistent with the cohort as a whole. Conclusions: In survivors of aggressive lymphomas, QoL improved primarily in the first year after diagnosis, and sustained over the course of nine years. QoL in survivors of aggressive lymphomas is higher than the United States general population at 1, 2, 3, 6, and 9 years after diagnosis. Figure Disclosures Maurer: Pfizer: Membership on an entity's Board of Directors or advisory committees; Nanostring: Research Funding; Morphosys: Membership on an entity's Board of Directors or advisory committees; Celgene / BMS: Research Funding; Kite: Membership on an entity's Board of Directors or advisory committees. Farooq:Kite, a Gilead Company: Honoraria. Cerhan:BMS/Celgene: Research Funding; NanoString: Research Funding.