Citations

Chloroethylagelastatin A (CEAA) is an analogue of agelastatin A (AA), a natural alkaloid derived from a marine sponge. It is under development for therapeutic use against brain tumors as it has excellent central nervous system (CNS) penetration and pre-clinical therapeutic activity against brain tumors. Recently, AA was shown to inhibit protein synthesis by binding to the ribosomal A-site. In this study, we developed a novel virtual screening platform to perform a comprehensive screening of various AA analogues showing that AA analogues with proven therapeutic activity including CEAA have significant ribosomal binding capacity whereas therapeutically inactive analogues show poor ribosomal binding and revealing structural fingerprint features essential for drug-ribosome interactions. In particular, CEAA was found to have greater ribosomal binding capacity than AA. Biological tests showed that CEAA binds the ribosome and contributes to protein synthesis inhibition. Our findings suggest that CEAA may possess ribosomal inhibitor activity and that our virtual screening platform may be a useful tool in discovery and development of novel ribosomal inhibitors.

IgG4-related disease (IgG4RD) with intracranial involvement is rare. We report a 56-year-old male who had an excellent response to rituximab and dexamethasone after going undiagnosed for 5 years. After 3 years of rituximab maintenance, he has no evidence of disease on brain MRI.

AbstractALK‐positive ALCL can lead to rapid irreversible destruction of the optic pathway. Early treatment should be instituted in patients with CNS involvement or those at increased CNS risk.

AbstractThis case illustrates an unusual presentation of paraneoplastic myositis in stage IV follicular lymphoma managed with high‐dose steroids, a previously unreported entity in the literature.

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]

Abstract Background: Previous studies have proposed combination of various factors that predict poor mobilization after GCSF stimulation. However, there is no single clinical or laboratory test that reliably correlates with bone marrow reserve and PBPC mobilization. Peripheral blood CD34+ cell count (pCD34) reliably correlates with PBPC mobilization and yield but only after GCSF administration. Methods: We have prospectively followed 36 autologous PBPC transplant candidates, from the time of initial evaluation to transplant, to evaluate factors the correlate with bone marrow reserve and autologous PBPC mobilization. Results: The patients median age was 63 (range 26 – 76). 21 of the 36 patients were diagnosed with dysproteinemia, primarily multiple myeloma, 10 patients had non-Hodgkin’s lymphoma while the remaining 5 had other form of hematological malignancies. Our evaluation shows baseline platelet count prior to growth factor administration significantly correlate with total CD34+ cell yield (spearman: r = 0.64, p &lt;0.001, Figure 1). In addition, daily platelet count during PBPC harvest correlate with CD34+ cell yield for the day (spearman: r = 0.6, p &lt;0.001). Using multiple linear regression model (F = 19.1, p &lt;0.001, R2 = 0.64), we have determined patients’ age (p = 0.03) and type of disease (p &lt;0.001), in addition to platelet count (p&lt;0.001), significantly correlate with total CD34+ cell yield. Further analysis showed low baseline platelet count predicts poor PBPC mobilization. Using Receiver Operating Curve (ROC), we have determined that platelet count of 174,000/ul was the best cut-off for collecting at least 2 million/Kg CD34+ cells with sensitivity of 81% and specificity of 78% and estimated correct classification of 81%. Even though pCD34 counts were slightly more sensitive and were better at identifying poor mobilizers in our cohort (best cut-off 10/ul, sensitivity 96%, specificity 67%, correct classification 89%), their clinical utility were diminished since the values were only known after GCSF administration. Conclusion: Baseline platelet count is a sensitive predictor of bone marrow reserve and can be used prior to growth factor administration to predict poor mobilization. Figure 1: Correlation of baseline platelet count and total CD34+ cell yield Figure 1:. Correlation of baseline platelet count and total CD34+ cell yield

TPS7570 Background: The DIAL study is testing the efficacy of dual immunomodulation in patients with advanced B cell non-Hodgkin lymphoma (B-NHL). Developed by the Cancer Therapy Evaluation Program (CTEP), the trial combines the use of a programmed cell death protein 1 (PD-1) inhibitor (nivolumab) with an agonist of the CD27 receptor (varlilumab) in a randomized phase 2 design. CD27, a co-stimulatory receptor, regulates T cell activation through interaction with CD70. T cell exhaustion plays a major role in immune evasion in B-NHL. Varlilumab is an agonistic IgG1 monoclonal antibody that recognizes CD27 leading to prevention or reversal of exhaustion. Varlilumab also demonstrates direct anti-tumoral activity in xenograft models of human lymphoma cell lines via antibody-dependent cell-mediated cytotoxicity. Phase 1 data supports the safety and tolerability of single-agent varlilumab in advanced hematologic malignancies. We hypothesize that CD27 activation synergizes with PD-1 inhibition resulting in a superior anti-lymphoma effect compared to PD-1 blockade alone. The study will also evaluate the effect of these agents on tumor and immune cells using IHC, mass cytometry (CyTOF), multiplex ELISA, imaging mass cytometry, and whole exome sequencing. Methods: The trial is enrolling patients with advanced aggressive B-NHL. Standard inclusion criteria and prior treatment with at least 2 lines of standard therapy are required. Prior autologous stem cell transplant and/or chimeric antigen receptor (CAR) T cell therapy is allowed. Patients with active CNS disease are excluded. Eligible patients will be randomized to treatment with single-agent nivolumab (group 1) or dual immunotherapy with nivolumab and varlilumab. Group 1 is allowed to cross-over at the time of progression. Nivolumab will be administered intravenously (IV) every 2 weeks (240 mg) for 4 months followed by monthly dosing thereafter (480 mg). Varlilumab will be given IV every 4 weeks (3 mg/kg). Response assessment will be done by PET-CT scan every 12 weeks. Primary outcome is overall response rate (ORR) according to the LYRIC criteria. The trial will enroll 48 patients per arm, allowing 80% power to detect at least 20% increase in ORR in the experimental arm (group 2) assuming a 25% ORR in the control arm (group 1). The trial is registered and open to participation to members of ETCTN and EDDOP. Clinical trial information: NCT03038672.