Moustafa, Muhamad Alhaj

A 26-year-old female developed bilateral blindness after a complete remission for ALK-positive ALCL. Initial workup showed neurolymphomatosis involving the bilateral optic nerves. She underwent hematopoietic cell transplantation and she remained in complete remission after 1 year; however her vision never improved. ALCL likely led to destruction of the optic pathway.

e20044 Background: Primary Cutaneous Diffuse Large B-cell Lymphoma, Leg-type (PCDLBCL) is a rare lymphoma comprising 4% of all cutaneous lymphomas with an aggressive clinical course. We investigated disease characteristics and outcomes among patients PCDLBCL. Methods: Following IRB approval, we identified patients retrospectively with PCDLBCL treated at the Mayo Clinic Cancer Center 1998-2019. Results: 45 pts were identified with a median age of 71 years (Range- 48-95) and 28 (62%) were female. Disease locations were legs (62%), arms (22%), head (11%), trunk (2%) and multiple sites (2%). At diagnosis, (51%) had a single lesion, (29%) had multiple lesions in 1-2 contiguous regions, (16%) had multiple lesions in non-contiguous regions or > 2 regions and data was not available (4%). Immunohistochemistry showed positive staining for BCL-2 (92%), BCL-6 (76%), c-MYC (62%), MUM1 (95%), CD10 (11%), and cytoplasmic IgM (8/9- 89%). By Han’s criteria, (95%) had activated B cell lymphoma (ABC). Median Ki-67 was 90% (range, 50,100%). 9/12 (75%) were positive for MYD88 L265P mutation. 13/21 (62%) were double expressor and 3/22 (14%) had double hit lymphoma. 37/45 (82%) had ECOG < 2. LDH was elevated in 13/37 (35%). The median number of therapies was 1 (range; 1-11). The initial treatments were chemo-radiation (30%), chemo alone (38%), rituximab alone (11%), radiation (RT) alone (16%), rituximab-RT (2.5%), and surgical (2.5%). The median follow-up time for the whole cohort was 80 months (95% CI; 32, 169). The median progression free survival and overall survival (OS) were 20 months (95% CI; 12, 34) and 80 months (95% CI; 48, 119). 22/45 (49%) are alive. The cause of death was disease-related in 11/23 (48%). The median number of relapses was 1 (range; 0, 11) with (60%) relapsed after first line. 4/45 pts had autologous stem cell transplant after relapse. 7/45 (16%) had a systemic relapse at a median time of 35 months from diagnosis (range; 16, 112). Age above 60 years was associated with worse OS; 70 months (95% CI; 30, 99) vs NR (95% CI; 135, NR), p = 0.025. ECOG performance status < 2 was associated with better OS, NR months (95% CI; 80, NR) vs 48 months (95% CI; 3.3, 88),p = 0.0003. 1 pt received Ibrutinib on 11th relapse and had 3 years of PFS. Conclusions: PCDLBCL is predominantly ABC type, affects elderly pts and is characterized by multiple cutaneous relapses followed in some cases by systemic relapses. Increased age and poor performance status had a negative impact on OS. High incidence of MYD88 L265P mutation is observed in PCDLBCL similar to immune-privileged site lymphomas.

e20036 Background: Hepatosplenic T cell lymphoma (HSTL) is a rare subtype of mature T cell lymphomas accounting for less than 1 percent of non-Hodgkin lymphomas. it has been associated with poor prognosis. It typically involves sinusoids in the spleen, liver, and bone marrow. Methods: Following IRB approval, we retrospectively evaluated patients with HSTL treated at the Mayo Clinic Cancer Center 1996-2019. Kaplan-Meier survival analysis and univariate analysis to identify prognostic factors were performed. We investigated clinical characteristics and outcomes among patients with HSTL. Results: 22 patients (15 males) with median age of 45.5 years (range- 15.5-80.6) were identified. The majority of patients had B symptoms (12/22), cyotpenias (20/22), massive splenomegaly (16/22), liver involvement (13/22), and/or bone marrow involvement (14/22). Additionally, 42% tested positive for peripheral blood involvement and 8/22 (36%) were on chronic immunosuppression related to solid organ transplant (2), inflammatory bowel disease (2), and rheumatologic disorders (4). Phenotypically, the majority of patients were positive for gamma/delta (18/22), isochromosome 7q (8/13), and 4/9 (44%) tested positive for trisomy 8. Initial therapies included CHOP/CHOEP (14), ICE (2), EPOCH (1), pentostatin (1), and radiation (1). The median follow-up was 33 months (range 2,137). Progression free survival and overall survival (OS) were 9.5 months (95% CI; 1.8, 16.3) and 12 months (95% CI; 4.9, 18.5) respectively. 10/22 (45%) underwent splenectomy with one patient receiving splenectomy alone as treatment. 8/22 (36%) had stem cell transplant (SCT- 5 allogeneic and 3 autologous). Out of the 22 patients 4 (18%) were long-term survivors with 55, 74, 95, and 137 months; 3/4 had splenectomy at diagnosis and 2/4 had allogeneic SCT. The longest survivor had splenectomy only. Liver involvement was associated with worse OS; 10 months (95% CI; 1.6, 18) vs 35 months (95% CI; 4, NR), p = 0.036. Immune suppression at diagnosis was associated with worse OS; 5 months (95% CI; 1.3, 18) vs 18 months (95% CI; 9, 74), p = 0.036. A trend for better OS was seen with splenectomy and SCT. Conclusions: HSTL is a rare lymphoma with poor prognosis. Long-term survival was seen in 18% only. Liver involvement and immune suppression had a negative impact on OS. A larger cohort is needed to better evaluate the impact of different treatment options.

e19543 Background: Langerhans cell sarcoma (LCS) is a very rare cancer with the reported incidence of 2 per 100,000,000. It originates from antigen presenting cells belonging to the dendritic cell/macrophage family. Methods: Following IRB approval, we identified LCS patients treated at the Mayo Clinic Cancer Center. Medical charts were reviewed to extract clinical data. Results: Our cohort consists of 5 patients with confirmed diagnosis of LCS. The median age at diagnosis was 34 years (range, 11-75) with 60% (3/5) females. One female was an African American and the rest were Caucasians. ECOG performance status at the time of diagnosis was 0 in 4 patients and 3 in 1 patient. Four patients had disseminated disease at diagnosis. 3/5 patients had moderate splenomegaly at diagnosis. 2/5 patients presented with a bulky mediastinal tumor and 1/5 patients presented with bulky intraabdominal disease. Predominant sites of disease are summarized in the table. BRAF mutation was negative in all 3 tested patients. The median follow up for the whole cohort was 25 months (range; 5, 41). Three patients relapsed after the initial treatment. Patient # 4 received allogeneic stem cell transplantation after the 4th relapse and is in CR 14 months later. Patient # 5 had PD-L1 expression > 95% and was started on pembrolizumab with sustained response for 1 year. Conclusions: LCS is extremely rare and is associated with unfavorable outcomes after currently available therapeutic interventions. More studies on the genetic and molecular basis of LCS are necessary to develop targeted therapies. [Table: see text]

e16662 Background: Cholangiocarcinoma (CCA) is a relatively rare malignancy accounting for 3% of gastrointestinal cancers in the US. While multiple risk factors for CCA are established and well-studied, other potential risk factors are still controversial and not well established. Herein, we used a large national database to investigate possible risk factors and associations. Methods: We used the National Inpatient Sample (NIS) database to review all admissions between 2011 and 2015. We grouped patients based on the presence and absence of CCA using the appropriate ICD-9 codes. We used multivariate logistic regression to assess the association between obesity, alcohol abuse, smoking, diabetes mellitus (DM), and non-alcoholic fatty liver disease (NAFLD). Results: We reviewed 30,955,295 admissions of which 20,030 had CCA. CCA Patients were older compared to the rest of the patients (mean age 67 years ±12.8 vs. 57±20.6, P < .001) and had less female patients (48% vs 59%, P < .001). Patients’ characteristics are shown in the table. After adjusting for viral hepatitis B (HBV), viral hepatitis C (HCV), liver cirrhosis, inflammatory bowel disease (IBD), primary sclerosing cholangitis (PSC), and bile duct stones, logistic regression showed DM to be proportionately associated with CCA (OR = 1.04, 95%CI[1.01-1.08], P < .001), whereas alcohol, smoking and obesity were all inversely associated with CCA; OR = 0.75, 95%CI [0.69-0.81], P < .001, OR = 0.75, 95%CI [0.71-0.79], P < .001 and OR = 0.71, 95%CI [0.67-0.75], P < .001, respectively. In addition, compared to whites, Hispanic and Asian/Pacific Islander races were proportionally associated with CCA; OR = 1.27, 95%CI [1.21-1.34], P < .001, and OR = 1.79, 95%CI, [1.67-1.92], P < .001, respectively, while black race was inversely associated with CCA (OR = 0.85, 95%CI [0.81-0.89], P < .001). Conclusions: In our large database study, we found that patients with diagnosis of DM or being from certain minority ethnic groups are associated with increased incidence of CCA. Other factors like alcohol and smoking were associated with decreased incidence of CCA, but those factors may be under reported. This raises the need for further evaluation for these factors and their effect on CCA incidence and outcomes in those specific groups. [Table: see text]

e16059 Background: Anal cancer is an uncommon malignancy accounting for less than 3% of gastrointestinal malignancies in the US. In this large database study, we aimed to re-evaluate the difference in the incidence and mortality trend in both genders. Methods: We used SEER 18 database to study anal cancer cases in the US during 2000-2016. Incidence and mortality rates of anal cancer were calculated by gender and were expressed by 1,000,000 person-years. Annual percent change (APC) was calculated using join point regression software. Results: We reviewed 25,418 patients with anal cancer, of which 61.4% were females. Incidence of anal cancers was 14.375 and 19.427 per 1,000,000 person-years, in males and females, respectively. Incidence rates of anal cancer significantly increased over the study period, but this increase was sharper in females (APC = 2.220%, 95%CI [1.924-2.517], P < .001) when compared to males (APC = 0.915%, 95%CI [0.303-1.531], P = .006). Mortality rates from anal cancer over the study period were 7.425 and 7.532 per 1,000,000 person-years, in males and females, respectively. Overall anal cancer mortality rates did not change between 2000-2009 but started to decrease starting from 2010 and this decrease became sharpest between 2014-2016; APC = -44.905%, 95%CI [-57.572- -28.457], P = .001). Mortality rates followed the same trend in both genders. Conclusions: Anal cancer incidence is increasing with significant increase in the incidence trend is noticed in females compared to males which is a change from the previous trend that was seen from 1973-2000. On the other hand, anal cancer mortality has started to decrease for the first time starting from 2010 with no difference in the mortality trend between males and females. This improvement in mortality rate can be explained by the improvement in early detection rate and possibly improvement in the treatment approach for these high-risk patients.

Targeted agents have greatly improved outcomes for patients (pts) with chronic lymphocytic leukemia (CLL) and other B cell lymphomas; however, single agents have been limited by intolerance, resistance and depth/durability of responses. Current novel targeted agent combinations may improve depth of response, but such "full dose" strategies have been associated with significant AEs, dose reductions/interruptions and discontinuations. Our in vitro & in vivo screening/optimization studies identified that concurrent inhibition of BTK & mTOR targets plus IMiD at low doses of each inhibitor can synergistically kill B-cell malignancies and may address drug-resistance. DTRM-555 is an optimized oral triplet combination of a novel BTK inhibitor DTRMWXHS-12 (DTRM-12) with everolimus (EV) & pomalidomide (POM). This once daily therapy was tested in a stepwise, phase I, US multicenter study in patients with highest unmet medical needs including r/r CLL, Richter's transformation (RT) of CLL, DLBCL, transformed B-cell lymphomas. We conducted a 3+3 design phase I, first human trial exploring DTRM-555 in pts ≥18 years, ECOG PS ≤1 with CLL, B-cell NHL, or Hodgkin lymphoma (HL) with no available standard therapy (NCT02900716). Our goal was to determine optimal doses for triplet combination therapy through 3 escalating phases of study: DTRM-12 in escalating doses (50, 100, 200, & 300 mg/day) in Part Ia, DTRM-12 at 200 mg or 300 mg & EV at 5 mg (doublet or DTRM-505) in Part Ib Arm A while DTRM-12 at 200 mg or 300 mg, EV at 5 mg & POM at 2 mg in Part Ib Arm B. For all arms, treatment was administered for 21 consecutive days of a 28-day cycle, until disease progression or unacceptable toxicity. Safety was the primary endpoint, and the dose-limiting toxicity (DLT) period was cycle 1. Secondary endpoints included response (iwCLL 2018 or Cheson 2014), progression free survival, duration of response and pharmacokinetics. Intra-patient migration between arms (Mono to doublet to triplet) was permitted if subsequent doses were tolerated. The trial commenced 9/27/2016 and completed enrollment 7/25/2019. Thirty-three pts were enrolled, including 2 screen failures and 4 intra-cohort migrations, with r/r DLBCL (n=8), CLL/SLL (n=5), RT (n=6), FL (n=5), MCL (n=4), MZL/LPL (n=3), HL (n=2). 30 of 31 treated pts were evaluated: 8 pts participated in phase Ia (DTRM-12) while 23 pts were treated on phase Ib combinations (DTRM-505 & DTRM-555). Baseline characteristics: 70% male (n=23), median age 70 years (range 46-94) and 94% white. Median prior therapies were 3 (range 1-10), 53% had been treated with ≥1 prior targeted agent (i.e., CD19/CD3 bispecific antibody, obtinutuzumab, pembrolizumab, nivolumab, ibrutinib, venetoclax, PI3k-i), CAR-T or HSCT. 35% pts were previously treated with ibrutinib. Table 1 describes Grade (Gr) 3 and 4 AEs (all causality, stratified by treatment arm). Regarding safety, AEs were manageable, with a total of 5 DLTs were observed: 2 (Gr 3 febrile neutropenia, URI) in part Ib arm A, 3 (Gr 4 thrombocytopenia, Gr 3 diarrhea, G3 febrile neutropenia) in Part Ib arm B. No MTD was reached for the mono & doublet arms, with the MTD of the triplet determined to be DTRM-12 200 mg, EV 5 mg, & POM 2 mg. Spider plot (Figure 1a) shows the clinical response for individual CLL and lymphoma pts treated with mono, doublet and triplet therapies. Depth and durability of response improved with combination therapies (vs. mono). Of note, 48% of all patients had a ≥50% reduction in sum of the products of lymph node diameters. Representative PET-CT scans are in Figure 1b-c. Responses in multi-refractory pts are ongoing (including 15+ mos in a pt with r/r DLBCL and 5+ mos PR in a pt aged &gt; 90 yrs with r/r DLBCL; 4+ & 13+ mos PRs in two pts with RT). DTRM-12 plasma concentrations were unaffected by EV & POM (Once Daily Oral Therapies) in Figure 1d. The clinical trial met its primary endpoint as the triple combination DTRM-555 had an acceptable safety profile. Dose dependent drug levels with minimal inter-pt variations were observed in all arms, supporting once daily oral administration of this low-dose combination therapy. Encouraging clinical activity was observed in several high-risk, multi-refractory CLL and lymphoma pts, including those previously treated with ibrutinib. Thus synthetic lethality is a viable treatment approach. A phase II US expansion study is underway targeting pts with transformed lymphomas (follicular or prior CLL) and r/r DLBCL cohorts. Table 1. Disclosures Mato: AbbVie: Consultancy, Research Funding; Sunesis: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; Johnson & Johnson: Consultancy, Research Funding; Celgene: Consultancy; AstraZeneca: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding; Gilead: Research Funding; Acerta: Consultancy; Janssen: Consultancy; TG Therapeutics: Consultancy, Other: DSMB member , Research Funding; LOXO: Consultancy, Research Funding; DTRM Biopharma: Research Funding. Schuster:DTRM Biopharma: Research Funding. Foss:Mallinckrodt: Consultancy; Acrotech: Consultancy; miRagen: Consultancy; Seattle Genetics: Consultancy, Other: fees for non-CME/CE services ; Eisai: Consultancy; Spectrum: Other: fees for non-CME/CE services . Isufi:Novartis: Consultancy; Astra Zeneca: Consultancy; Celgene: Consultancy. Ding:Merck: Research Funding; DTRM Biopharma: Research Funding. Brander:Novartis: Consultancy; MEI: Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy; BeiGene: Research Funding; AstraZeneca: Consultancy, Research Funding; Acerta: Research Funding; Tolero: Research Funding; AbbVie: Consultancy, Honoraria, Research Funding; Genentech: Consultancy, Honoraria, Research Funding; Teva: Consultancy, Honoraria; TG Therapeutics: Consultancy, Honoraria, Research Funding; DTRM Biopharma: Research Funding. Tun:Mundi-pharma: Research Funding; TG Therapeutics: Research Funding; Curis: Research Funding; DTRM Biopharma: Research Funding; Celgene: Research Funding; BMS: Research Funding. He:DTRM Biopharma: Employment, Equity Ownership. Kearney:DTRM Biopharma: Employment, Equity Ownership. Gui:DTRM Biopharma: Employment, Equity Ownership. Anderson:Theradex: Employment. Roeker:AbbVie: Equity Ownership; Abbott Laboratories: Equity Ownership. Huntington:Bayer: Consultancy, Honoraria; AbbVie: Consultancy; Celgene: Consultancy, Research Funding; Genentech: Consultancy; Pharmacyclics: Honoraria; DTRM Biopharm: Research Funding. OffLabel Disclosure: Everolimus in B cell lymphomas and CLL Pomalidomide in B cell lymphomas and CLL

Multiple myeloma (MM) treatment has advanced significantly over the last 2 decades. In most patients, the disease course has been altered from early fatality to chronic morbidity with multiple lines of treatment. The MM treatment paradigm has shifted toward treating patients before end-organ damage occurs. Thus, timeliness of treatment initiation in this era might improve patient outcomes. This is the first report to our knowledge analyzing disparities and trends in treatment timeliness of patients with MM using the National Cancer Database. Multiple factors affected the timing of treatment initiation in MM and disparities were found. We noted that initiation of treatment was delayed in women (odds ratio [OR], 1.15; 95% CI, 1.1 to 1.2) and blacks (OR, 1.21; 95% CI, 1.14 to 1.28; reference, whites) and in patients diagnosed in more recent years (2012-2015; OR, 1.15; 95% CI, 1.1 to 1.22; reference, 2004-2007). Patients were likely to start treatment earlier if they were age ≥ 80 years (OR, 0.83; 95% CI, 0.76 to 0.9; reference, age < 60 years), were uninsured (OR, 0.81; 95% CI, 0.72 to 0.91; reference, private insurance), had Medicaid (OR, 0.87; 95% CI, 0.79 to 0.95; reference, private insurance), were treated in a comprehensive community cancer program (OR, 0.7; 95% CI, 0.65 to 0.77; reference, community cancer program), lived in a location other than the US Northeast, or had a higher Charlson comorbidity score. Patient education and income levels did not affect time to treatment initiation. Particular aspects of these disparities could be explained by our current health care system and insurance rules, whereas others need to be investigated more deeply.

AbstractPrimary appendiceal lymphomas (PAL) are a type of primary gastrointestinal non‐Hodgkin lymphoma (PGINHL) with an incidence of <1%. There is considerable discordance with regard to the optimal management of PGINHL. We describe two cases of PAL, perform a literature review, and discuss the available evidence for optimal treatment.

Abstract Background: Normalization of serum free light chain ratio (FLCr) following achievement of a complete response (CR) to therapy denotes a stringent CR in multiple myeloma, and is associated with improved overall survival (OS). However, its value in patients achieving less than a CR is not clear. We hypothesized that patients in whom FLCr normalizes with the initial anti-myeloma therapy will have an improved outcome, even in the absence of a CR. Methods: We analyzed the medical records of patients with MM who were evaluated at Mayo Clinic, Rochester, MN between January 2004 and December 2011, seen within 90 days of diagnosis. We selected patients with measurable disease on serum protein electrophoresis, defined as a serum M-spike ≥1 g/dl at the time of diagnosis. Then, we excluded all patients with negative immunofixation for monoclonal M-protein in serum and urine at their first response as well as those who did not have serum FLC results available from the time of their first best response. M protein measurements were collected serially from the time of diagnosis until the time of the first relapse or last follow up date if no relapse was recorded. Progression-free survival (PFS) and OS were analyzed using the Kaplan-Meier method. Results: Out of the 1354 MM patients seen at our institution during this period, a total of 453 patients were included in our study. The median age of the cohort at the time of diagnosis was 65 (range, 29-91); 49% were older than 65 years and 284 (63%) were male. The estimated median follow up for the whole cohort was 66 months (95% CI; 61, 71); 241 patients were alive with a median follow up of 4.7 years (range, 0.4 to 10). Three hundred and seventy three (82%) patients had relapsed following the initial therapy with a median time to progression (TTP) of 19.5 months (95% CI; 18, 22) and PFS of 19 months (95% CI; 17, 20). The median OS for the entire cohort is 67 months (95% CI; 59, 73). The median time to the best first response was 6.9 months (range: 0.3-83 months). At the time of the best first response 154 patients (34%) had normal FLCr. Patients with normal FLCr had a longer PFS (29 vs. 16 months, P< .0001) and OS (91 vs. 58 months, P= .0002). We then examined the impact of FLCr normalization on survival outcomes according to their IMWG response categories. We found that FLCr normalization had a favorable impact on PFS in each of the three groups [very good partial response (VGPR), Partial response (PR), and Stable disease (SD)], However, when looking at the OS, only patients with PR had a better OS associated with a normal sFLC κ/λ ratio (Table 1). Conclusions: Obtaining a normal sFLC ratio appears to confer a more favorable prognosis irrespective of the depth of the response, suggesting an important role for serial-sFLC measurements in disease monitoring even in patients who achieve only a PR to therapy as their best response. This supports the inclusion of sFLC at all levels of response included in the current International Myeloma Working Group (IMWG) criteria. Abstract 3427. Table 1 Effect of FLCr normalization according to IMWG response categories SD PR VGPR Normal FLCr Abnormal FLCr p-value Normal FLCr Abnormal FLCr p-value Normal FLCr Abnormal FLCr p-value Number of patients 7 70 62 157 85 60 PFS, month, median (95% CI) 27 (14, 36) 7 (5, 12) < .02 26 (20, 36) 17 (13, 20) .0005 29 (23, 32) 21 (18, 26) .03 OS, months, median (95% CI) 68 (49, 68) 41 (31, 61) > .1 NR (65, NR) 61 (50, NR) .004 74 (67, 107) 73 (59, NR) > .9 • Abbreviations: NR; statistically not reached •• Progressive disease (PD) was not included because none of the 12 patients achieved a normal FLCr. Disclosures No relevant conflicts of interest to declare.