Karyopharm Therapeutics Research Articles

Dramatic Resolution of HLH after Treatment with the JAK 1/2 Inhibitor, Ruxolitinib

Introduction: Preclincal murine models of primary and secondary hemophagocytic lymphohistiocytosis (HLH) have demonstrated the role of JAK/STAT signaling in propagating the cytokine-mediated hyperinflammatory state. Das et al. (Blood 2016) demonstrated that ruxolitinib (rux) effectively attenuates murine HLH, and Albeituni et al. (Blood 2019) found it superior to IFN-γ inhibition (the target of emapalumab-lzsg). A few single case reports exist in which rux was used for salvage therapy, however they report only limited clinical success and/or were used as a bridge to allogeneic stem cell transplantation. Here we present a series of three consecutive cases in which rux was employed as either salvage therapy for relapsed/refractory secondary HLH or front-line for moderate HLH manifestations. Importantly, each patient was maintained on a taper of rux which prevented recurrence and obviated the need for allogeneic transplantation. Two of the three patients have been tapered completely off rux without recurrence of either laboratory or clinical manifestations of HLH at the time of this submission. Case 1: Patient 1 is a 24 yo woman who had initially presented to an outside hospital with jaundice and was found to have a warm AIHA. She was initially started on steroids, but developed worsening anemia, fever, splenomegaly, and encephalopathy. On transfer to us she had ferritin of 58,505 ng/ml. Her bone marrow biopsy demonstrated abundant hemophagocytosis (Fig. 1B,C). She met HLH criteria and was started on HLH-94 protocol; however, her total and direct bilirubin climbed dramatically, peaking at 95.2 and 82.0 mg/dl, respectively. Rux 5mg BID was initiated as salvage therapy, and within 48 hours, her labs significantly improved, her fevers resolved, and she became responsive to blood transfusions (Fig. 1A). After two weeks on rux, she developed recurrent hemolysis. Her dose was increased to 20mg BID, resulting in a complete resolution of her hemolysis, fevers, transaminitis and hyperbilirubinemia. After 3 months of clinical stability, rux was tapered. She has been off rux now for three months. Case 2: Patient 2 is a 26 yo woman who presented with unremitting fevers and myalgias, and was found to have an acute hepatitis C infection. Her ferritin was 24,023ng/ml, and a bone marrow biopsy demonstrated abundant hemophagocytosis. She initially responded to the HLH-94 protocol; however, attempts to hold treatment following induction were met with recurrent fevers, encephalopathy, and hyperferritinemia. She transferred to us, and a repeat bone marrow biopsy demonstrated persistent hemophagocytosis (Fig. 2B,C), while her ferritin was 15,073 ng/ml. We initiated salvage treatment with rux 10mg BID. Her fevers, encephalopathy, and lab abnormalities quickly improved; her ferritin fell to 2,973ng/ml within 3 days (Fig. 2A). A small subsequent elevation in her ferritin prompted an increase of the rux to 20mg BID. She improved and was discharged on rux maintenance at 20mg BID. Since discharge, she remains asymptomatic with mildly elevated ferritin levels, mild pancytopenia, and is tolerating a slow wean of rux without incident. Case 3: Patient 3 is a 40 yo man with a diagnosis of hairy cell leukemia who received 5 days of cladribine. He developed febrile neutropenia 2 days following the end of chemotherapy. His infectious workup was negative with the exception of a positive peripheral blood EBV DNA PCR. He developed a mononucleosis-like syndrome, with persistent high fevers, splenomegaly, and hyperferritinemia to 6684 ng/ml. He also developed hepatic dysfunction with a direct hyperbilirubinemia peaking at 14.1 mg/dl and coagulopathy. He was treated initially with dexamethasone without resolution. A bone marrow biopsy demonstrated abundant hemophagocytosis (Fig. 3B,C). Given modest manifestations and concern that chemotherapy would exacerbate his immunosuppression, rux was initiated at 10mg BID. The liver dysfunction rapidly improved, and fevers resolved within 3 days (Fig. 3A). All other manifestations resolved within 1 week, and he was able to taper and discontinue rux within 2 months. Conclusions: The preclinical data by Albeituni et al. coupled with our clinical observations suggest that ruxolitinib may be a viable alternative to aggressive chemotherapy regimens such as HLH-94 or anti-IFN-γ (emapalumab-lzsg) therapy for HLH, and clinical trials should be considered. Disclosures DiPersio: Karyopharm Therapeutics: Consultancy; Cellworks Group, Inc.: Membership on an entity's Board of Directors or advisory committees; NeoImmune Tech: Research Funding; Macrogenics: Research Funding, Speakers Bureau; Bioline Rx: Research Funding, Speakers Bureau; RiverVest Venture Partners Arch Oncology: Consultancy, Membership on an entity's Board of Directors or advisory committees; Magenta Therapeutics: Equity Ownership; WUGEN: Equity Ownership, Patents & Royalties, Research Funding; Amphivena Therapeutics: Consultancy, Research Funding; Incyte: Consultancy, Research Funding; Celgene: Consultancy. OffLabel Disclosure: Ruxolitinib was used off-label for the treatment of Hemophagocytic Lymphohistiocytosis (HLH) in the relapsed/refractory setting and in a patient who was unable to tolerate standard therapy. This was not in a clinical trial, but reported as a case series

Olutasidenib (FT-2102), an IDH1m Inhibitor As a Single Agent or in Combination with Azacitidine, Induces Deep Clinical Responses with Mutation Clearance in Patients with Acute Myeloid Leukemia Treated in a Phase 1 Dose Escalation and Expansion Study

Olutasidenib (FT-2102), an IDH1m Inhibitor As a Single Agent or in Combination with Azacitidine, Induces Deep Clinical Responses with Mutation Clearance in Patients with Acute Myeloid Leukemia Treated in a Phase 1 Dose Escalation and Expansion Study

Ixazomib or Lenalidomide Maintenance Following Autologous Stem Cell Transplantation and Ixazomib, Lenalidomide, and Dexamethasone (IRD) Consolidation in Patients with Newly Diagnosed Multiple Myeloma: Results from a Large Multi-Center Randomized Phase II Trial

Ixazomib or Lenalidomide Maintenance Following Autologous Stem Cell Transplantation and Ixazomib, Lenalidomide, and Dexamethasone (IRD) Consolidation in Patients with Newly Diagnosed Multiple Myeloma: Results from a Large Multi-Center Randomized Phase II Trial

A Phase 2 Study to Assess the Feasibility and Tolerance of the Combination of Elotuzumab, Lenalidomide, and Dexamethasone (ERd) in the Induction, Consolidation, and Maintenance Treatment of Transplant-Eligible Patients Newly Diagnosed with Multiple Myeloma (MM)

Background: The introduction of novel agents such as proteasome inhibitors (PI) and immunomodulatory drugs (IMiDs) with and without corticosteroids has revolutionized treatment (tx) and improved survival rates for MM. IMID/PI triplets such as VRD (bortezomib, lenalidomide, dexamethasone), VTD (bortezomib, thalidomide, dexamethasone), or KRD (carfilzomib, lenalidomide, dexamethasone) are preferred inductions for transplant-eligible patients (pts). Unfortunately, the PI often has unique safety events such as peripheral neuropathy (PN) or cardiac issues that can impact the quality of life. Elotuzumab is a mAb with a dual mechanism of action (tagging MM cells and activating NK cells by binding SLAMF7). The combination of elotuzumab, lenalidomide, and dexamethasone (ERd), is active, well-tolerated, and approved by the FDA for pts with relapsed MM. In this study, we will determine the feasibility of incorporating ERd into a transplant-eligible pt population. Methods: Pts with newly diagnosed MM requiring chemotherapy planning to undergo autologous stem cell transplantation (ASCT) were enrolled. Induction of elotuzumab at 10 mg/kg was administered IV on days (D) 1, 8, 15, 22 of the 1st 2 28-day cycles and days 1, 15 of the third and fourth 28-day cycles. Lenalidomide was dosed at 25 mg orally on D 1-21 of each 28 day induction cycle. Dexamethasone was administered IV concurrent with elotuzumab (28mg orally 3-24 hours prior to infusion and 8 mg IV with elotuzumab), with 40 mg orally administered on D 8 and 22 of cycles 3 and 4. After completion of the 4 induction cycles, pts proceeded to mobilization and ASCT though pts who refused transplantation were allowed to proceed directly to consolidation and maintenance if the investigator believed the pt was deriving benefit. 70-120 days after ASCT, 4 cycles of consolidation were administered (dosing similar to cycles 3-4 of induction but with lenalidomide at 15mg). Pts then went on to maintenance with elotuzumab 20 mg/kg IV on D 1, oral lenalidomide 10mg +/- 5 mg D 1-21 and dexamethasone 28mg oral/8 mg IV prior to elotuzumab infusion were dosed in 28-day cycles for up to 24 months. The primary endpoint was the induction feasibility rate (IFR) defined as the percentage of pts successfully completing 4 cycles of induction tx with ERd and able to start ASCT. Secondary end points were complete response rate (≥nCR), overall response rate (≥PR), progression-free survival (PFS) and overall survival (OS). AEs were assessed according to CTCAE V4 and responses were assessed using the revised IMWG criteria. Results: 52 pts were enrolled: 56% male, median age 61 ys, 12% RISS III, 21% high-risk cytogenetics [17p del, t(4;14), and/or t(14;16)]. To date, 26 (50%) pts remain on active tx. 4 pts refused transplantation despite being eligible and were excluded from the IFR calculation. The IFR was 69% and the best overall response rate (ORR) was 92% (69% ≥ VGPR). With a median follow up of 20 mos, median PFS and OS for all pts were not reached. The 18 mo PFS and OS were 83% and 89% respectively. The most common AEs were fatigue (59.6%), diarrhea (42.3%) and nausea (42.3%). PN was seen in 29%, and all events were ≤ G2. There were 28 SAEs in 20 pts, including 12 tx-related SAEs. There was 1 tx-related death due to heart failure in a pt with no history of prior cardiac issues who had subsequent therapy. 29% of pts met the high-risk (HR) criteria (defined as RISS III or high risk cytogenetics) and 29% of pts were considered standard-risk (RISS I and no high-risk cytogenetics). The best ORR was 87% (67% ≥ VGPR) for HR pts and 93% (53% ≥ VGPR) for SR pts and the IFR was 57% for HR pts and 64% for SR pts. The median PFS and OS were 20.5 mos and 22.0 mos respectively for HR pts and have not been reached for SR pts. Conclusions: ERd induction, consolidation and maintenance was feasible and well tolerated in conjunction with ASCT in transplant-eligible pts. Despite high ORR for all pts, HR patients had inferior PFS and OS. This study supports the continued evaluation of this regimen in SR pts. Disclosures Berdeja: Amgen Inc, BioClinica, Celgene Corporation, CRISPR Therapeutics, Bristol-Myers Squibb Company, Janssen Biotech Inc, Karyopharm Therapeutics, Kite Pharma Inc, Prothena, Servier, Takeda Oncology: Consultancy; Poseida: Research Funding; AbbVie Inc, Amgen Inc, Acetylon Pharmaceuticals Inc, Bluebird Bio, Bristol-Myers Squibb Company, Celgene Corporation, Constellation Pharma, Curis Inc, Genentech, Glenmark Pharmaceuticals, Janssen Biotech Inc, Kesios Therapeutics, Lilly, Novartis, Poseida: Research Funding. Gregory:Takeda: Speakers Bureau; Celgene: Speakers Bureau; Poseida: Research Funding; Amgen: Speakers Bureau. OffLabel Disclosure: Yes, this was an investigational clinical study of the combination of elotuzumab, lenalidomide, and dexamethasone in the induction, consolidation, and maintenance treatment of transplant-eligible patients newly diagnosed with multiple myeloma.

Diagnostic Testing Patterns and Concordance with World Health Organization (WHO) Criteria for Patients (Pts) with Newly Diagnosed (ND) Myelodysplastic Syndromes (MDS) in the Connect® MDS/AML Registry

Diagnostic Testing Patterns and Concordance with World Health Organization (WHO) Criteria for Patients (Pts) with Newly Diagnosed (ND) Myelodysplastic Syndromes (MDS) in the Connect® MDS/AML Registry

Type I Interferon Response Identified through Phenotypic and Transcriptional Profiling of Circulating Immune Cells during Idiopathic Multicentric Castleman Disease Flare

Idiopathic multicentric Castleman disease (iMCD) is a rare hematologic illness involving episodic disease flares with polyclonal cytokine-induced lymphoproliferation, systemic inflammation, and life-threatening multi-organ dysfunction. iMCD is further classified by clinical features and the most severe cases of iMCD often fall into the thrombocytopenia, anasarca, fever/elevated C-reactive protein, reticulin myelofibrosis, renal dysfunction, and organomegaly (TAFRO) clinical subtype. A cytokine storm involving interleukin(IL)-6 drives disease pathogenesis in a subset of patients, however only 34% of patients were found to respond to anti-IL-6 therapy with siltuximab in its registrational clinical trial. The identification of next generation therapeutics for iMCD-TAFRO patients has been challenging as the etiology, pathological cell types, and signaling pathways involved in iMCD-TAFRO are largely unknown. In this study, we aimed to identify cellular drivers and pathophysiological mechanisms of iMCD-TAFRO through the use of an unbiased multi-omics approach. We obtained paired bulk peripheral blood mononuclear cells (PBMCs) from a cohort of ten iMCD-TAFRO patients isolated during disease flare and clinical remission. These paired PBMC samples were utilized for flow cytometry to assess immune cell frequency and phenotype between iMCD-TAFRO flare and remission as well as between flare and age/sex matched healthy donors (n = 10). Three paired iMCD-TAFRO samples were also selected for transcriptional profiling using single-cell RNA sequencing (scRNAseq). We observed phenotypic differences across the T cell, monocyte, and NK cell compartments. We observed a significant increase in the frequency of CD8 T cells within the T cell compartment as well as an increased frequency of granzyme B and perforin expressing CD8 T cells in iMCD-TAFRO flare compared to healthy donors. We also observed a significant increase in the frequency of CD56+ NK cells within the NK cell compartment and a significant increase in the frequency of CD14+ monocytes within the monocyte compartment during iMCD-TAFRO flare compared to healthy donors. Together, these data suggest activation and involvement of CD8 T cell, NK cell, and monocyte subsets during iMCD-TAFRO flare. We next utilized Gene Set Enrichment Analysis (GSEA) of our single-cell transcriptomics dataset to ask whether circulating immune cell frequencies display enrichment of the 50 Hallmark gene sets during flare compared to remission across three iMCD-TAFRO patients. We found significant enrichment (FDR < 0.01) of genes within the Interferon Alpha Response gene set in circulating non-naïve CD8 T cells, classical monocytes, nonclassical monocytes, NK cells, and dendritic cells. These data suggest that a number of circulating immune cell populations may be responding to Type I interferon (IFN-I) during iMCD-TAFRO flare. In addition, our group has recently reported mTORC1 activation in iMCD and has characterized in three iMCD-TAFRO patients a clinical response following mTOR inhibition with sirolimus. Within our scRNAseq dataset, we identified mTORC1 signaling to be enriched only in circulating classical and nonclassical monocytes during flare. Having observed enrichment of both the Interferon Alpha Response Gene set and the mTORC1 signaling gene set in circulating monocytes, we then asked whether the relative expression of IFN-I response genes and mTORC1 signaling genes are correlated within circulating classical and nonclassical monocytes. Indeed, we observed a significant positive correlation between the average relative expression of mTORC1 signaling genes and IFN-I Response genes across classical, but not nonclassical, monocytes from all three iMCD-TAFRO patients (all R2 ≥0.6, p<0.0001).These data suggest a potential link between IFN-I signaling and mTORC1 signaling activation in classical monocytes in iMCD-TAFRO flare. Following further characterization of this association, we propose investigation into the use of Janus kinase (JAK) inhibitors in iMCD, as JAK is a proximal signaling molecule downstream of the IFN-alpha/beta receptor (IFNAR) and upstream of mTORC1 signaling. In summary, this dataset demonstrates involvement of multiple immune cell populations and identifies IFN-I signaling as a novel inflammatory gene program that may contribute to iMCD-TAFRO pathogenesis and drive treatment identification. Disclosures van Rhee: Takeda: Consultancy; Sanofi Genzyme: Consultancy; Castleman Disease Collaborative Network: Consultancy; EUSA: Consultancy; Adicet Bio: Consultancy; Kite Pharma: Consultancy; Karyopharm Therapeutics: Consultancy. Fajgenbaum:Janssen Pharmaceuticals: Research Funding.

Geno-Clinical Model for the Diagnosis of Bone Marrow Myeloid Neoplasms

Geno-Clinical Model for the Diagnosis of Bone Marrow Myeloid Neoplasms

CD45-ADC Plus Janus Kinase (JAK) Inhibitors As Conditioning for MHC-Mismatched Murine Hematopoietic Stem Cell Transplantation Is Associated with Minimal Toxicity and Graft Versus Host Disease

INTRODUCTION: Allogeneic hematopoietic stem cell transplantation (alloHSCT) provides the best chance for disease control in acute myeloid leukemia (AML). The known anti-leukemia benefit of alloHSCT is attributable to pre-transplant conditioning with chemotherapy and/or radiation and the graft-versus-leukemia (GvL) effect. However, the utility of alloHSCT is limited by significant treatment-related morbidity and mortality resulting from conditioning regimen-related toxicities and graft versus host disease (GvHD). AML is primarily diagnosed in elderly patients, for whom alloHSCT may be contraindicated due to an inability to tolerate these adverse effects. Therefore, an unmet clinical need exists for novel alloHSCT conditioning regimens that minimize toxicity without sacrificing therapeutic efficacy. Previously, we and others (Palchaudhuri et al. (2016), Nat Biotech; Persaud et al. (2018), Blood) have shown that antibody-drug conjugates (ADCs) composed of a CD45.2-specific antibody linked to the ribosome-inactivating protein saporin (CD45-SAP) permitted stable, high-level engraftment in murine syngeneic HSCT. We hypothesize that such targeted, immunotherapeutic strategies can be applied to the setting of alloHSCT, enhancing its safety and applicability to the treatment of hematologic diseases. METHODS: For engraftment studies, recipient mice were conditioned with 3 mg/kg CD45-SAP 7 days prior to infusion of 10-20 x 106 whole bone marrow cells. The following alloHSCT models were used: MHC-matched (BALB/c→DBA/2), F1-to-parent (CB6F1→B6), and F1-to-F1 (B6CBAF1→CB6F1). In some experiments, CD45-SAP treatment was combined with CD4+ and CD8+ T cell depletion and/or the Janus kinase (JAK) inhibitor, baricitinib. For GvHD studies, a parent-to-F1 (B6→CB6F1) model was used in which recipients were infused with 25 x 106 donor splenocytes after CD45-SAP treatment or sublethal irradiation. For studies with human CD45-SAP, MOLM13 AML cell line viability was measured with XTT assays, and cord-blood CD34+cell colony formation was assessed using methylcellulose assays. RESULTS: CD45-SAP combined with CD4+ and CD8+ T cell depletion allowed high-level engraftment in MHC-matched and F1-to-parent alloHSCT models (Figure 1A-B). Baricitinib, previously shown by our lab to prevent GvHD while preserving the GvL effect (Choi et al. (2018), Leukemia), permitted short-term HSC engraftment in F1-to-parent alloHSCT when mice were dosed daily with the drug during the first 21 days post-HSCT (Figure 1C). Graft stability in baricitinib-treated mice was improved by either combining daily baricitinib treatment with pre-transplant T cell depletion (Figure 1D), or by delivering baricitinib via continuous infusion (Figure 1E). In parent-to-F1 GvHD models, CD45-SAP conditioned mice showed minimal morbidity or mortality when infused with allogeneic splenocytes, whereas mice conditioned with sublethal irradiation succumbed within 3 weeks to severe GvHD (Figure 1F). That alloreactive T cells did not cause GvHD in CD45-SAP treated mice prompted us to use donor lymphocyte infusions to enhance engraftment in a fully haploidentical (F1-to-F1) HSCT model. Our results suggest that addition of donor T cells to the bone marrow graft promotes donor engraftment without eliciting clinically apparent GvHD (Figure 1G). Finally, anti-human CD45 (clone BC8), when conjugated to saporin, inhibited MOLM13 cell growth and cord blood CD34+ cell colony formation in vitro (Figure 1H-I), consistent with both an anti-stem cell and anti-leukemic effect. CONCLUSIONS: Combining CD45-SAP with T cell depletion and/or pharmacologic immunomodulation with the JAK inhibitor baricitinib effectively conditions mice for engraftment of MHC-matched and haploidentical HSCs without causing significant toxicity. Strikingly, mice conditioned with CD45-SAP, unlike mice conditioned with irradiation, did not develop GvHD when infused with allogeneic splenocytes. Finally, we have demonstrated that human CD45-SAP is cytotoxic to both the MOLM13 AML cell line and cord-blood derived stem cells. Taken together, these studies provide key proof-of-principle evidence that targeted immunotherapeutics (CD45-SAP plus JAK inhibitors) can accomplish the goals of alloHSCT - creating marrow space for donor HSCs, overcoming immune barriers to engraftment, and eliminating leukemia cells - with limited toxicity or GvHD. Disclosures Cooper: Wugen: Consultancy, Equity Ownership, Patents & Royalties. Rettig:WashU: Patents & Royalties: Patent Application 16/401,950. DiPersio:Incyte: Consultancy, Research Funding; Celgene: Consultancy; Amphivena Therapeutics: Consultancy, Research Funding; Cellworks Group, Inc.: Membership on an entity's Board of Directors or advisory committees; RiverVest Venture Partners Arch Oncology: Consultancy, Membership on an entity's Board of Directors or advisory committees; NeoImmune Tech: Research Funding; Macrogenics: Research Funding, Speakers Bureau; WUGEN: Equity Ownership, Patents & Royalties, Research Funding; Magenta Therapeutics: Equity Ownership; Karyopharm Therapeutics: Consultancy; Bioline Rx: Research Funding, Speakers Bureau.

PTPN11 Mutated Acute Myeloid Leukemia (AML) Features an Abundant Epichaperome Network and Is Sensitive to the Epichaperome Inhibitor PU-H71

PTPN11 Mutated Acute Myeloid Leukemia (AML) Features an Abundant Epichaperome Network and Is Sensitive to the Epichaperome Inhibitor PU-H71

Long-Term Outcome of Total Therapy Regimens: Impact of Molecular Subgroups

Introduction. Our TT regimens for newly diagnosed multiple myeloma (MM) incorporate novel agents into a sequential treatment program comprising induction, tandem autologous stem cell transplantation and consolidation followed by 3 years of maintenance. Herein, we report the very long-term results in a large cohort of 1986 patients treated on successive TT protocols, the most mature of which (TT1, 2, and 3a) have a median follow-up ranging from 12.8 to 23.1 yrs. Methods. TT1 (1990) was followed by TT2 (1998), which introduced Thalidomide (T) in a randomized fashion. TT3 used bortezomib (V) throughout, with TT3a (2003) and 3b (2006) having different maintenance. TT3a used in year 1 of maintenance V, T and dexamethasone (D) and in years 2 and 3 TD. TT3b introduced lenalidomide (R) during maintenance for 3 years together with V and D. TT4 (2009) only enrolled patients with GEP-defined low risk disease and randomized patients to a standard arm or light arm using a similar regimen as TT3b. TT5 (2009) was specifically designed for patients who have a high 70-gene score and employed a dose dense treatment approach. Finally, TT6 (2009) accrued previously treated, patients irrespective of GEP-defined risk using a treatment schema similar to that used in TT5. Gene expression profiling was used to assign molecular classifications. These include HY (hyperdiploidy), LB (gene expression patterns frequently seen in patients with fewer focal bone lesions), MF (spikes in MAF and MAFB expression), MS (hyperactivation of MMSET +/- FGFR3), PR (over-expression of proliferation-related genes), and CD-1 or CD-2 (different forms of aberrant CCND1 and CCND3 expression). A mixed parametric cure model was used to estimate the proportion of patients with long-term, event-free survival, or the "cure fraction." When using progression free survival (PFS) in the model, the cure fraction is the percent of patients who are likely to never experience relapse based on trends in the survival times that have been observed. When using complete remission duration (CRD) in the model, the model estimates the cure fraction among patients who achieved complete response. Results. The median follow-up on the entire cohort patients was 11.6 years (range: 0.0-27.6) The median overall survival was 9.2 years, with 79.3% and 48.0% having an event-free survival greater than 3 and 10 years, respectively. Overall, patients with GEP70 low risk MM had estimated PFS and CRD cure fractions of 20.1% and 32.7%, respectively. GEP70 high risk MM patients fared much worse with estimated cure fractions of only 8.2 and 11.0%. The estimated PFS- and-CRD based cure fractions increased over time with successive protocols (PFS-cure: 6.0% in TT1 to 27.7% in TT4; CRD-cure: 9.3 to 49.8%). These cure fractions were consistent with the early plateau in the PFS and CRD curves seen at 9 years in TT4 patients. The highest cure fractions were seen in the CD-1 molecular group (34.9 and 40.3%) with intermediate outcomes in the HY (20.1 and 30.0%) and MS (22.8 and 33.5%) groups (Table 1). Surprisingly, low cure fractions were observed in the LB (1.1 and 13.5%) and CD-2 groups (13.5 and 26.4%). CD-1, LB and CD-2 groups had similar 5-yr PFS rates of 60, 60 and 63% respectively, but a steady low rate of relapse was observed in the CD-2 and especially the LB group. These findings were confirmed in a 5-yr landmark analysis showing high PFS and CRD cure fractions in the CD-1 group of 62.7 and 72.3% respectively contrasting to much lower cure fractions in the CD-2 (47.2 and 49.2%) and LB (30.8 and 45.0%) groups. Conclusions. We report excellent long-term outcomes in patients with GEP70 low risk MM and cure fractions in the range of 20-30%. Patients with LB and CD-2 subgroups have lower overall cure rates, despites similar initial 5-yr PFS rates compared to the superior performing CD-1 group, which can be explained by the occurrence of late relapses. Table 1 Disclosures van Rhee: EUSA: Consultancy; Adicet Bio: Consultancy; Takeda: Consultancy; Sanofi Genzyme: Consultancy; Kite Pharma: Consultancy; Karyopharm Therapeutics: Consultancy; Castleman Disease Collaborative Network: Consultancy. Walker:Celgene: Research Funding. Davies:Janssen, Celgene: Other: Research Grant, Research Funding; Amgen, Celgene, Janssen, Oncopeptides, Roche, Takeda: Membership on an entity's Board of Directors or advisory committees, Other: Consultant/Advisor. Morgan:Amgen, Roche, Abbvie, Takeda, Celgene, Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Other: research grant, Research Funding. OffLabel Disclosure: anti-CD38 monoclonal antibody targeting myeloma

Preliminary Results of a Phase 1 Dose Escalation Study of the First-in-Class Anti-CD74 Antibody Drug Conjugate (ADC), STRO-001, in Patients with Advanced B-Cell Malignancies

Preliminary Results of a Phase 1 Dose Escalation Study of the First-in-Class Anti-CD74 Antibody Drug Conjugate (ADC), STRO-001, in Patients with Advanced B-Cell Malignancies

Immune Landscapes Predict Chemotherapy Resistance and Anti-Leukemic Activity of Flotetuzumab, an Investigational CD123×CD3 Bispecific Dart® Molecule, in Patients with Relapsed/Refractory Acute Myeloid Leukemia

Immune Landscapes Predict Chemotherapy Resistance and Anti-Leukemic Activity of Flotetuzumab, an Investigational CD123×CD3 Bispecific Dart® Molecule, in Patients with Relapsed/Refractory Acute Myeloid Leukemia

Clinical Outcomes and Health-Related Quality of Life (HRQoL) Among Randomized Clinical Trial (RCT)-Eligible and RCT-Ineligible Patients: Results from the Connect® MM Registry

Clinical Outcomes and Health-Related Quality of Life (HRQoL) Among Randomized Clinical Trial (RCT)-Eligible and RCT-Ineligible Patients: Results from the Connect® MM Registry

Ibrutinib Treatment Mitigates Phenotypic Alterations of Non-Neoplastic Immune Cell Compartments in Chronic Lymphocytic Leukemia

Ibrutinib Treatment Mitigates Phenotypic Alterations of Non-Neoplastic Immune Cell Compartments in Chronic Lymphocytic Leukemia

Clinical Benefit of Glasdegib in Combination with Azacitidine or Low-Dose Cytarabine in Patients with Acute Myeloid Leukemia

Clinical Benefit of Glasdegib in Combination with Azacitidine or Low-Dose Cytarabine in Patients with Acute Myeloid Leukemia

Quantitative Changes in Serum Proteins Including CXCL13 Are Early Indicators of Response to Anti-IL6 Therapy in Idiopathic Multicentric Castleman Disease

Background Human herpes virus-8 (HHV8) negative/idiopathic multicentric Castleman disease (iMCD) is a rare hematological disorder with one FDA-approved treatment and no early indicators of patient response after treatment is commenced. Clinical onset can be sudden and severe, involving polyclonal lymphoproliferation with characteristic dysmorphic germinal centers, constitutional symptoms, systemic inflammation and life-threatening cytokine storm-driven multi-organ failure. CXCL13, a key regulator of lymph node germinal center development, was recently found to be the most elevated cytokine in iMCD flare, but the clinical significance of this finding is not yet clear. Interleukin-6 (IL-6) is the known driver of pathogenesis in a portion of patients and the target of the only FDA-approved treatment, siltuximab. In the Phase II study of siltuximab (NCT01024036), one-third of patients met response criteria, which were assessed after a minimum of 48 weeks. Early indicators of response to siltuximab are urgently needed to inform clinicians about the likelihood of patient response to therapy, adjust treatments if needed, and identify novel therapeutic targets for siltuximab non-responders. Methods Clinical data and serum samples were collected as part of NCT01024036. We measured serum protein analytes in the 52 subjects who were treated with anti-IL6 therapy, as well as the 26 patients in the control arm, at day 1, day 8, and day 64 of therapy (infusions administered every 21 days). Serum samples from 44 healthy donors were also analyzed. Of the 1,305 analytes measured using SomaLogic SOMAscan, 1,178 passed QC and were included in analyses. Each analyte was log2 transformed and capped at the 2.5th and 97.5th percentiles. Response to anti-IL6 therapy was determined by independent review in NCT01024036. Data processing was performed using the Medidata Rave Omics machine learning platform and R v3.4.4. Linear mixed effects models were used to detect whether kinetic changes in protein expression were associated with anti-IL6 response. Upon running the full model with the selected covariates, the p-values of the interaction between time point and response were used to test for differences between responders and non-responders. A separate model was fitted using each protein, and False Discovery Rates (FDR) were estimated by the Benjamini-Hochberg method with alpha < 0.05. Results Seven days after siltuximab was first administered (day 8), 9 proteins were significantly different between responders and non-responders: IgA, BCMA, NPS-PLA2, ART, IL-18 BPa, CD5L, b2-Microglobulin, CXCL13, and NRP1. All 9 of these proteins were significantly decreased in responders compared to non-responders. At day 64, the number of significantly different proteins increased to 121, including 8 of the 9 proteins from day 8; NPS-PLA2 did not achieve significance at day 64. This result indicates that there may be early indicators of response in serum as early as day 8. Given that CXCL13 was recently discovered as a key cytokine in iMCD, the early and significant decline of CXCL13 in responders versus non-responders was highly notable (Day 8: FDR = 0.02, Day 64: FDR = 0.005). Prior to treatment, CXCL13 was significantly higher in this cohort of iMCD patients than in a group of age-matched healthy donors (p = 8.19e-09). By day 64, CXCL13 levels in siltuximab responders decreased to levels approaching the healthy donor range but remained elevated in non-responders and placebo patients. Conclusions This analysis represents the first use of high-quality serum proteomics data to study early indicators of response to treatment in a rare hyperinflammatory, lymphoproliferative disorder. The decline in CXCL13 levels in responders and continued elevation in non-responders suggests that CXCL13 is downstream of IL-6 in responders and independent of IL-6 signaling in non-responders. CXCL13, along with several other proteins that demonstrated significant decline by day 8 including IgA and beta2-microglobulin, can be routinely measured and could serve as a panel that indicates the likelihood of response soon after commencing therapy, if validated in a separate cohort. These proteins could also provide a more continuous scale of response than traditional outcome measures. Given that iMCD may have a sudden and severe onset, early indicators of response to anti-IL6 therapy are critical for timely treatment administration. Figure Disclosures Katz: Medidata Solutions: Employment. Nabel:Thermo Fisher: Patents & Royalties: royalty income. Diamond:Brigham and Women's Hospital and Harvard Medical School's Department of Medicine, Division of Genetics, Genomes2People Translational Genomics Research Program: Consultancy. Karvir:Medidata Solutions: Employment. Zhang:Medidata Solutions: Employment. Reddy:Janssen Pharmaceuticals: Employment, Equity Ownership. Guilfoyle:Janssen Pharmaceuticals: Employment, Equity Ownership. Tendler:Janssen Pharmaceuticals: Employment, Equity Ownership. van Rhee:Takeda: Consultancy; Sanofi Genzyme: Consultancy; Castleman Disease Collaborative Network: Consultancy; EUSA: Consultancy; Adicet Bio: Consultancy; Kite Pharma: Consultancy; Karyopharm Therapeutics: Consultancy. Beineke:Medidata Solutions: Employment. Oromendia:Medidata Solutions: Employment, Equity Ownership. Fajgenbaum:Janssen Pharmaceuticals: Research Funding.

Changes in Gut Microbial Diversity and Correlations with Clinical Outcomes in Patients with Newly Diagnosed Acute Myeloid Leukemia (AML) Receiving Intensive Chemotherapy

Changes in Gut Microbial Diversity and Correlations with Clinical Outcomes in Patients with Newly Diagnosed Acute Myeloid Leukemia (AML) Receiving Intensive Chemotherapy

High Sensitivity NGS Analysis of MRD in CLL Patients Prospectively Treated with Ibrutinib Plus FCR (iFCR)

High Sensitivity NGS Analysis of MRD in CLL Patients Prospectively Treated with Ibrutinib Plus FCR (iFCR)

Updated Results from an Ongoing Phase 1 Clinical Study of bb21217 Anti-Bcma CAR T Cell Therapy

Updated Results from an Ongoing Phase 1 Clinical Study of bb21217 Anti-Bcma CAR T Cell Therapy

JAK2V617F Clonal Hematopoiesis Stratifies By Peripheral Blood Counts.

Background:Patients with clonal hematopoiesis (CH) in the absence of WHO-classified myeloid disease are of special interest given their increased prevalence with age, predisposition to morbid cardiovascular complications, and amplified risk of overt hematologic malignancy. Pts are often stratified by normal peripheral blood counts into clonal hematopoiesis of indeterminate potential (CHIP), or those with unexplained cytopenias as clonal cytopenias of undetermined significance (CCUS). However, less is known about pts with elevated counts and clonal hematopoiesis who do not fulfill WHO criteria for any myeloproliferative neoplasia (MPN). We leveraged Vanderbilt University Medical Center's unique biobank, BioVU, to identify the prevalence of JAK2V617Facross 48,000 pts to evaluate the clinical changes in progression from CH to overt myeloid disease. Methods:To develop a reference JAKV617Ftraining set, next generation sequencing via Illumina Trusight Myeloid Panel (NGS) was performed on BioVU samples (N=133) from pts with confirmed myeloproliferative malignancy. Of those pts, 78 harbored JAK2V617Fwith a range of variant allele frequencies (VAF). Matched samples in this training set (N=133) were also analyzed via Infinium® Expanded Multi-Ethnic Genotyping Array (MEGAEX). SNP array JAK2V617Fvariant intensity was extracted (rs77375493; NM_004972.3(JAK2): c.1849G>T (p.Val617Phe). A regression model was built using NGS VAF as a dependent variable and MEGAEX intensity data as independent variable (r2=0.9931).Based on this model, we imputed JAK2V617FVAF for all 48,000 pts in our cohort. Pts with JAK2V617Fwere subdivided into: clinically confirmed myeloid disease, or JAK2V617Fwithout a diagnosis of MPN. Upon review of the EMR, the latter group was further dived into: 1) probable undiagnosedMPN, 2) CHIP, 3) CCUS, or 4) CH with associated elevated peripheral blood counts (CHAPbc). Only lab values after the date of JAK2V617Fdetection were included. Confirmed malignancy was defined by WHO classification of disease. Pts with evidence of possible WHO classified PV or ET with Hgb >18.5g/dl in men, >16.5g/dl in women, or PLT count >450k/mcl regardless of gender were classified as probable undiagnosedMPN. CHIP was defined as JAK2V617Fwithout abnormal counts across a patient's EMR lifetime, except when confounding events, e.g. trauma surgery or overt iron deficiency anemia, incorrectly skewed values. CCUS was defined as JAK2V617Fin the presence of unexplained cytopenias; hemoglobin (Hgb) <13.5g/dl men or <12g/dl women, leukocyte count (WBC) <3.9x10^3/uL or platelet (PLT) <135 x10^3/mcL. We classified pts with elevated blood counts who did not meet the WHO classification of MPN [e.g. WBC >10.7 regardless of gender, Hgb 18-18.5 g/dL in men or 16.0-16.5 g/dL in women with maximum Hgb no greater than 18.5g/dl in men and 16.5g/dl in women, or PLT count between 371-450k/mcl regardless of gender (and no values >450k/mcl)] as CHAPbc. Results:We identified 410 of 48,000 pts who harbored JAK2V617F(0.85% prevalence). Of those, 270/410 had clinically diagnosed hematologic malignancy including primary myelofibrosis (PMF) (79), ET (48), PV (43) and Ph-MPN NOS (29). MDS (29), AML (15), NHL (16), plasma cell dyscrasias (5), CML (3), other (3). There were 19/410 with insufficient clinical data to determine diagnosis. The remaining 121/410 JAK2V617Fpts did not have a related diagnosis. Figure 1a demonstrates imputed VAF differences in JAK2V617Fbetween known MPN vs. CH (including undiagnosed MPN) by age (mean VAF 0.44 vs. 0.17 respectively P<0.001). We identified several undiagnosed MPNs (22), which subdivided into polycythemia predominant (1), thrombocythemia predominant (16) or a combination of polycythemia and thrombocythemia (5). The remaining 99/410 cases were CH,with CHIP (55), CCUS (29), and CHAPbc (15). Ranges of blood counts appear to be a continuous variable among JAK2V617Fpts with CH or undiagnosed MPN (Fig 1b-1d). Summary: We used an unbiased approach to identify the prevalence of JAK2V617Facross all pts at a single institution. In this cohort, hematologic malignancy and CH did stratify by imputed VAF. Further, within JAK2V617FCH, CHAPbc may be differentiated from CHIP by clinical phenotype and further investigation will be required to determine its impact on patient outcomes. Disclosures Savona: Sunesis: Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Incyte Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees; Boehringer Ingelheim: Patents & Royalties; Selvita: Membership on an entity's Board of Directors or advisory committees; Karyopharm Therapeutics: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Celgene Corporation: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding.