Kharfan‐Dabaja, Mohamed A.

BackgroundUpfront autologous hematopoietic stem cell transplantation (AHCT) remains an important therapy in the management of patients with multiple myeloma (MM), a disease of older adults.MethodsThe authors investigated the outcomes of AHCT in patients with MM who were aged ≥70 years. The Center for International Blood and Marrow Transplant Research (CIBMTR) database registered 15,999 patients with MM in the United States within 12 months of diagnosis during 2013 through 2017; a total of 2092 patients were aged ≥70 years. Nonrecurrence mortality (NRM), disease recurrence and/or progression (relapse; REL), progression‐free survival (PFS), and overall survival (OS) were modeled using Cox proportional hazards models with age at transplantation as the main effect. Because of the large sample size, a P value <.01 was considered to be statistically significant a priori.ResultsAn increase in AHCT was noted in 2017 (28%) compared with 2013 (15%) among patients aged ≥70 years. Although approximately 82% of patients received melphalan (Mel) at a dose of 200 mg/m2 overall, 58% of the patients aged ≥70 years received Mel at a dose of 140 mg/m2. On multivariate analysis, patients aged ≥70 years demonstrated no difference with regard to NRM (hazard ratio [HR] 1.3; 99% confidence interval [99% CI], 1‐1.7 [P = .06]), REL (HR, 1.03; 99% CI, 0.9‐1.1 [P = 0.6]), PFS (HR, 1.06; 99% CI, 1‐1.2 [P = 0.2]), and OS (HR, 1.2; 99% CI, 1‐1.4 [P = .02]) compared with the reference group (those aged 60‐69 years). In patients aged ≥70 years, Mel administered at a dose of 140 mg/m2 was found to be associated with worse outcomes compared with Mel administered at a dose of 200 mg/m2, including day 100 NRM (1% [95% CI, 1%‐2%] vs 0% [95% CI, 0%‐1%]; P = .003]), 2‐year PFS (64% [95% CI, 60%‐67%] vs 69% [95% CI, 66%‐73%]; P = .003), and 2‐year OS (85% [95% CI, 82%‐87%] vs 89% [95% CI, 86%‐91%]; P = .01]), likely representing frailty.ConclusionsThe results of the current study demonstrated that AHCT remains an effective consolidation therapy among patients with MM across all age groups.

AbstractIntroductionLenalidomide maintenance, commonly prescribed in the postautologous transplantation (AHCT) setting for multiple myeloma (MM), is associated with development of secondary primary malignancies (SPM). Proteasome inhibitor maintenance (PIM) has also been evaluated in MM. We conduct a systematic review/meta‐analysis to assess the efficacy of PIM in MM.MethodsPerforming a comprehensive search of the medical literature using PubMed/Medline and EMBASE on September 11, 2019, we extracted data on clinical outcomes related to benefits (OS, PFS, and depth of hematologic response [DOHR]) and harms (SPM and adverse events). 2144 references were identified; three studies were eligible for inclusion.ResultsA total of 1760 patients were included in the analysis; 507 patients received bortezomib and 395 received ixazomib maintenance. Control arms were either placebo (n = 261) or thalidomide (n = 358). PIM did not improve OS (HR 0.88, 95% CI 0.73‐1.05, P = .15) but improved PFS (HR 0.77, 95% CI 0.69‐0.86, P ≤ .00001) and DOHR (HR 0.88, 95% CI 0.79‐0.98, P = .02) compared with control. There were no significant differences between PIM and control regarding SPM (p = NS) and ≥grade 3 peripheral neuropathy (PN) (p = NS).ConclusionsPIM following AHCT in MM improves PFS and DOHR without an increase in development of SPM or severe PN compared with placebo/thalidomide.

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.

Abstract Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare hematologic malignancy with dismal clinical outcomes. Conventional chemotherapies such cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) and hyperfractionated cyclophosphamide, vincristine, doxorubicin, dexamethasone alternating with high-dose cytarabine and methotrexate (CVAD) have been commonly used for the BPDCN treatment until a recent study showed promising outcomes in patients treated with SL-401 (Tagraxofusp). In this single-institution retrospective study, we identified a total of 49 consecutive BPDCN patients. Among 42 patients who received treatment, hyper-CVAD regimen was associated with higher complete response rate compared with CHOP-based regimens or SL-401 (91% vs 50% vs 50%), although the difference did not achieve statistical significance. Furthermore, there was no significant overall survival (OS) difference between patients treated with SL-401 vs other chemotherapies as their first-line treatment (hazard ratio = 1.597; 95% CI, 0.460-5.548; P = .431). Of note, patients who received allogeneic stem cell transplant (allo-SCT) had significantly longer OS (hazard ratio = 0.160; 95% CI, 0.0453-0.56; P = .041). Extent of disease (skin vs bone marrow vs both) or younger age (&lt;60 years old) did not have significant prognostic impact on OS. Collectively, our study confirmed the survival benefit of allo-SCT and suggests that conventional and intensive chemotherapies such as CHOP and hyper-CVAD as well as SL-401 would be comparable first-line choice for the BPDCN patients.

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.

Abstract Allogeneic hematopoietic cell transplantation (HCT) is the only curative therapy for myelofibrosis (MF). In this large multicenter retrospective study, overall survival (OS) in MF patients treated with allogeneic HCT (551 patients) and without HCT (non-HCT) (1377 patients) was analyzed with Cox proportional hazards model. Survival analysis stratified by the Dynamic International Prognostic Scoring System (DIPSS) revealed that the first year of treatment arm assignment, due to upfront risk of transplant-related mortality (TRM), HCT was associated with inferior OS compared with non-HCT (non-HCT vs HCT: DIPSS intermediate 1 [Int-1]: hazard ratio [HR] = 0.26, P &lt; .0001; DIPSS-Int-2 and higher: HR, 0.39, P &lt; .0001). Similarly, in the DIPSS low-risk MF group, due to upfront TRM risk, OS was superior with non-HCT therapies compared with HCT in the first-year post treatment arm assignment (HR, 0.16, P = .006). However, after 1 year, OS was not significantly different (HR, 1.38, P = .451). Beyond 1 year of treatment arm assignment, an OS advantage with HCT therapy in Int-1 and higher DIPSS score patients was observed (non-HCT vs HCT: DIPSS-Int-1: HR, 2.64, P &lt; .0001; DIPSS-Int-2 and higher: HR, 2.55, P &lt; .0001). In conclusion, long-term OS advantage with HCT was observed for patients with Int-1 or higher risk MF, but at the cost of early TRM. The magnitude of OS benefit with HCT increased as DIPSS risk score increased and became apparent with longer follow-up.