Forma Therapeutics Research Articles

Impact of Minimal Residual Disease and Achievement of Complete Remission/Complete Remission with Partial Hematologic Recovery (CR/CRh) on Overall Survival Following Treatment with Gilteritinib in Patients with Relapsed/Refractory (R/R) Acute Myeloid Leukemia (AML) with FLT3 Mutations

Impact of Minimal Residual Disease and Achievement of Complete Remission/Complete Remission with Partial Hematologic Recovery (CR/CRh) on Overall Survival Following Treatment with Gilteritinib in Patients with Relapsed/Refractory (R/R) Acute Myeloid Leukemia (AML) with FLT3 Mutations

Global Chromatin Occupancy and Epigenetic Signature Analysis Reveal New Insights into the Function of GATA1 N-Terminus in Erythropoiesis

Mutations in GATA1 are seen in rare cases of dyserythropoietic anemia and in a subset of patients with Diamond Blackfan Anemia (DBA). Of note the truncation mutations in DBA, known as GATA1s, closely resemble those that are more commonly associated with acute megakaryoblastic leukemia in children with Down syndrome (DS). Studies with a mouse model of the Gata1s mutation revealed that replacement of the full-length protein by the shortened isoform led to a marked yet transient enhancement in megakaryopoiesis, similar in some respects to transient myeloproliferative disorder in DS. Furthermore, these mutant mice displayed impaired embryonic erythropoiesis but ostensibly no defects in adult hematopoiesis. In our efforts to better understand the connection between GATA1s and DBA, we comprehensively studied erythropoiesis in the Gata1s mouse strain. We observed a striking impairment in erythropoiesis in fetuses at E10.5 though E12.5, but saw improvement as the animals progressed through E14.5 and beyond. Defects included impaired terminal maturation and reduced numbers of erythroid progenitors, likely at the expense of expanded megakaryopoiesis. RNA-sequencing revealed that both erythroid genes and megakaryocytic genes were altered by the Gata1s mutation. Epiproteomic histone modification analysis further revealed there was an accumulation of H3K27 methylation in the R3 (CD71hiTer119hi) erythroid progenitor population, which suggests that GATA1 has a link to the epigenetic machinery that is altered in Gata1s mutant cells. Despite a global increase in H3K27me3, critical Gata2 regulatory elements in Gata1s mutant erythroid progenitors were marked by substantially less H3K27me3 than in wild-type littermates. Given that overexpression of GATA2 has been reported to impair erythropoiesis, we investigated whether reducing the GATA2 levels would ameliorate the phenotype. Indeed, we observed that haploinsufficiency for Gata2 rescued the erythroid defects of Gata1s fetuses. Next, to comprehensively study the effect of absence of the GATA1 N-terminus genome-wide, we performed Cleavage Under Targets and Release Using Nuclease (CUT&RUN) with H3K27me3, GATA1 or GATA1s antibodies on wild-type versus Gata1s expressing fetal erythroid cells. Our data indicated that there is a substantial reduction in H3K27me3 along regulatory elements of the Runx1 gene at the late stage (R3) of fetal erythropoiesis in Gata1s mice. Along with an increase in Runx1 expression we observed strong downregulation of Klf1, a repressive target of RUNX1. Thus, failure of GATA1s to facilitate trimethylation of Runx1 and Gata2 regulatory elements appears to cause the defects in erythroid cell and megakaryocyte development. In parallel, we performed an in-depth analysis of the phenotype of adult Gata1s mice and discovered that they have reduced red cell counts, lower hemoglobin and hematocrit, increased extramedullary hematopoiesis and impaired stress erythropoiesis compared to control littermates. Although there were significantly more megakaryocyte erythrocyte progenitors (MEPs, Lin-c-Kit+Sca-1-CD34-FcgR-) in Gata1s mouse bone marrow, there were fewer pre-colony-forming unit erythroid cells (preCFU-E, Lin-c-Kit+Sca-1-CD41-FcgR-CD150hiCD105hi), likely at the expense of expanded megakaryocyte progenitors (MkP, Lin-c-Kit+Sca-1-CD41+CD150hi).Gata1s mice also developed an MDS-like disease with age. Together, our integrated genomic analysis of transcriptome, GATA1/GATA1s chromatin binding profile and chromatin signature reveal that, although Gata1s mice do not precisely model DBA, they provide novel insights into the role of the N-terminus of GATA1 in gene transcriptional regulation, lineage determination and red blood cell maturation. DisclosuresCrispino:Scholar Rock: Research Funding; Forma Therapeutics: Research Funding.

Dynamins 2 and 3 Are Required for Human Megakaryocytes Directional Migration

Abstract:Megakaryocytes (MKs) undergo directional migration from the proliferative osteoblastic niche within the bone marrow (BM) environment to the capillary-rich vascular niche for platelet production and release into the pulmonary circulation. This process is regulated, in part by dynamins, large GTPase proteins that regulate cellular functions such as endocytosis, vesicle transport and cell migration. Additional functions of dynamins include the formation of actin-rich structures, such as lamellipodia and dorsal membrane ruffles, invadopodia and podosomes. Previous studies have shown that mutations in Dynamin 2 (DNM2) cause thrombocytopenia in humans. To explore the function of dynamins in megakaryocyte migration and platelet production in more depth, we monitored the response of cells to chemotaxis SDF1α gradient signal by a microfluidic device-based approach. We observed an impaired directional migration by both human megakaryocytic cell lines and primary cells treated either with dynasore, a small molecule inhibitor of dynamins, or shRNA knockdown of Dynamin 2 and 3 (DNM2, DNM3). Since directional cell migration is tightly regulated by actin cytoskeletal rearrangements, we next measured actin polymerization and RhoA activity. We observed a profound decrease in the F-actin and Rho GTPase activity upon loss of DNM2 and DNM3 function. Next, since the response to chemoattractant signal is navigated by SDF1 through its receptor CXCR4, we explored the CXCR4 receptor response to ligand in dynamin defective megakaryocytes. Interestingly we observed an increase in CXCR4 expression in the dynasore treated primary human cells. Additionally, combined inhibition of DNM2 and DNM3 or over expression of dominant negative Dnm2-K44A or GTPase-defective DNM3 decreased the active β1- integrin (ITGB1) activity, which indicates a decrease in the integrin mediated endo/exocytic cycling during cell migration. Finally, to understand the role of dynamin in endosome recycling, we assayed the distribution of Rab11, a marker of recycling endosomes. We noticed an abnormal clustered staining pattern of Rab11 in dynasore-treated MKs which is indicative of a disruption in recycling pathways. This observation suggests decreased recruitment of the recycling pathway in dynasore-treated cells. Altogether, in this study we demonstrate that dynamins regulate MKs directional migration towards the SDF1α chemotaxis signal in the bone marrow and governs endocytosis and cell receptor trafficking. DisclosuresCrispino:Scholar Rock: Research Funding; Forma Therapeutics: Research Funding.

Early Results from a Biomarker-Directed Phase 2 Trial of Sy-1425 in Combination with Azacitidine or Daratumumab in Non-APL Acute Myeloid Leukemia (AML) and Myelodysplastic Syndrome (MDS)

Early Results from a Biomarker-Directed Phase 2 Trial of Sy-1425 in Combination with Azacitidine or Daratumumab in Non-APL Acute Myeloid Leukemia (AML) and Myelodysplastic Syndrome (MDS)

1497P - JNJ-61186372 (JNJ-372), an EGFR-cMET bispecific antibody, in advanced non-small cell lung cancer (NSCLC): An update on phase I results

Background: JNJ-372 has demonstrated activity in EGFR and cMET-driven tumor models. In an ongoing phase 1 study of JNJ-372 in patients (pts) with advanced NSCLC, 1050 mg was identified as a recommended phase 2 dose in dose escalation (Part 1) and is being explored in the dose expansion of pts with EGFR-mutated (mut) NSCLC (Part 2). Methods: Pts were treated with JNJ-372 IV weekly x 4W for cycle 1, then biweekly thereafter. Pharmacokinetic (PK) sampling was taken at multiple time points for all pts in Part 1 and for the first 6 pts in Part 2. Disease evaluations were performed every 8 weeks. Tumors were characterized at baseline through next-generation sequencing of ctDNA and/or tumor tissue. Results: As of April 13th, 2018, 55 pts received JNJ-372 in Part 1 (n = 30) or Part 2 (n = 25), with 21 pts (38%) continuing therapy. Median age was 63y, 40% were male, 96% were Asian, and median prior systemic therapies was 2. The most frequent (≥15%) adverse events (AEs) were infusion-related reaction (56%), rash/acneiform dermatitis (53%), dyspnea (20%), paronychia (24%), nausea (22%), constipation (18%), stomatitis (18%), decreased appetite (18%), pruritus (16%), fatigue (16%), and peripheral edema (16%). AEs were mostly grade 1-2, with 3 ≥grade 3 treatment-related AEs (myalgia, neutropenia, and peripheral edema, all grade 3). PK was linear and dose proportional at doses ≥350 mg, with faster clearance PK at the 140-mg dose. Of the 30 response-evaluable pts with EGFRmut disease, treated at doses ≥700 mg, there are 8 partial responses (PRs; 4 confirmed PRs). This includes 6 pts with L858R or Exon19del primary mutations, and acquired resistance to first and/or third-generation EGFR tyrosine kinase inhibitors (TKIs), and 2 pts with primary Exon20ins disease. Activity was also observed in 2 pts with EGFRwt disease (squamous cell carcinoma and pleomorphic adenocarcinoma), each with -20% change in sum of largest diameter. The longest duration of treatment was 13.6 months. Conclusions: JNJ-372 is a novel EGFR-cMET bispecific antibody with a manageable safety profile consistent with EGFR and cMET inhibition. Preliminary evidence suggests JNJ-372 can have activity in EGFR-driven NSCLC, including pts resistant to EGFR TKIs. Clinical trial identification: NCT02609776 First posted: November 20, 2015. Editorial acknowledgement: Writing support was provided by Tracy T. Cao, PhD of Janssen Global Services, LLC. and funded by Janssen Global Services, LLC. Legal entity responsible for the study: Janssen Research & Development. Funding: Janssen Research & Development. Disclosure: B.C. Cho: Research funding: Janssen, Novartis, AstraZeneca, Yuhan, Champions Oncology, Abbvie, Dong-A ST, Ono, MOGAM; Honoraria: AstraZeneca, Novartis, MSD, Ono, Roche; Consulting or Advisory role: Janssen, AstraZeneca, Novartis, MSD, Roche, Yuhan; Speakers’ bureau: Novartis J-Y. Han: Research funding: Roche. E. Haura: Research funding: Lilly, Novartis, Boehringer Ingelheim, Janssen, Ignyta, Forma Therapeutics; Consulting or Advisory role: Janssen; Patent: Patent pending on PLA technology related to kinase inhibitor sensitivity biomarkers; Travel/Accommodations: Bristol-Myers Squibb, Roche. J. Bauml: Research funding: Merck, Novartis, Carevive Systems, Janssen, Bayer; Consulting or Advisory Role: Clovis, Bristol-Myers Squibb, Celgene, Boehringer-Ingelheim, AstraZeneca, Genentech, Guardant Health. R.E. Sanborn: Research funding: Merck (investigator-initiated study), Bristol-Myers Squibb (institutional research support), MedImmune (institutional research support); Honoraria: AstraZeneca; Consulting or Advisory Role: AstraZeneca, Seattle Genetics, Takeda, Genentech, Abbvie, Celldex; Travel/Accommodations: Janssen. M. Curtis, E. Attiyeh, N. Haddish-Berhane, K. Bae, R. Knoblauch, L. Sherman, M.V. Lorenzi: Employment: Janssen Stock: Johnson & Johnson. All other authors have declared no conflicts of interest.

Preliminary Results from a Phase 1 Study of Gilteritinib in Combination with Induction and Consolidation Chemotherapy in Subjects with Newly Diagnosed Acute Myeloid Leukemia (AML)

Preliminary Results from a Phase 1 Study of Gilteritinib in Combination with Induction and Consolidation Chemotherapy in Subjects with Newly Diagnosed Acute Myeloid Leukemia (AML)

Celgene and Forma extend discovery pact

Celgene will put another $195 million into Forma Therapeutics to expand their small-molecule drug discovery partnership to include targets in the areas of protein homeostasis, inflammation,immunology, and neurodegeneration. Forma is based in Watertown, Mass., with chemistry operations in Branford, Conn. The two firms established their pact in 2013 and extended it in 2014.

A Multi-Center Prospective Study Utilizing a Simplified Treatment Algorithm Complemented By Expert Support Decreases Induction Mortality and Improves Survival in Acute Promyelocytic Leukemia (APL). Results of the APL Trial in Georgia, South Carolina and Neighboring States

Background: APL is a highly curable malignancy with reported survival above 90% in many co-operative group studies. However these spectacular results are not evident in the general population. US SEER data and other population based studies from Swedish Cancer Registry and Brazil showed that early deaths (ED) can be as high as 30%, leading to a considerably lower survival compared to clinical trials where ED is around 5-10%. Decreasing ED remains a global challenge and the highest priority at all leukemia treatment centers and will result in population wide survival in this most curable leukemia. We report results of our prospective trial using a set of simplified treatment guidelines along with expert support designed to decrease ED.Methods: A network of leukemia treatment centers was established in Georgia, South Carolina and neighboring states. An aggressive outreach effort was made by visiting most of the leukemia treatment centers to publicize the concept and educate treating physicians in the community about ED in APL. The protocol provides a simplified two page treatment algorithm that emphasizes quick diagnosis, prompt initiation of therapy and proactive and aggressive management of the major causes of death during induction. Expert and treating physician communication was established very early when a diagnosis of APL was suspected and was maintained until the completion of induction. Study was approved by local IRBs (if applicable) and funded by the Lymphoma Leukemia Society (LLS). Informed consent was obtained upon confirmation of a diagnosis of APL and there were no exclusion criteria. Patient accrual was initiated in July 2013 and continued till May 2016 when the accrual goal of 120 was met on an intent to treat basis. Statistics are descriptive.Results: Between 7/2013 and 5/2016, 120 patients were enrolled at 5 large leukemia centers (n=54, 45%) and 24 community hospitals (n=66, 55%). Only 3 hospitals treated more than 3 APL patients/year. Median age was 54 years (range 21-84 years). 68 were male. 84% were low risk (WBC < 10,000/mm3) and median WBC count was 4.3 (range 0.3-170,000/mm3). ATRA was initiated at suspicion of APL diagnosis in 100% of patients and was the only treatment in 2(1.5%) patients. Arsenic was combined with ATRA in 93 (81.5%) patients while the other 17% received chemotherapy. 15(13%) had bleeding complications at presentation. Treatment course was complicated by infection and differentiation syndrome (DS) in 31(28%) and 40(34%) patients respectively.There were 12 early deaths, of which 1 was a Jehovah's Witness who declined transfusions and 1 who enrolled 12 days after diagnosis while in multi-organ failure. Incidence of ED was 10/118 (8.5%). The cause of death was disseminated intravascular coagulation (DIC) (n=4), DS (n=2), infection (n=1), anemia (n=1), multi-organ failure (n=4). With a median follow-up of 10.6 months, 2 low risk patients relapsed: I due to non-compliance 1 year after diagnosis and 1 with CNS relapse 3 months after completing consolidation. With a median follow up of 320 days (range 1-965) overall survival (Figure 1) was 87%. There were four late deaths; relapse (n=1), second cancer (n=1) and non-APL related comorbidities (n=2).Conclusions: Results of this prospective trial showed that a simplified treatment algorithm along with support from experts and co-management with treating physicians in the community decreased induction mortality (8.5%) and improved survival (87%) compared to SEER data (1 year relative survival of 71%). We believe our experience warrants large scale implementation and is presently approved as an ECOG/ACRIN trial (EA9131). This model can be applicable to other cancers and life-threatening diseases. [Display omitted] DisclosuresJillella:Leukemia Lymphoma Society: Research Funding. Heffner:AbbVie: Research Funding; Pharmacyclics: Research Funding; Celgene: Research Funding; Millennium: Research Funding. Stuart:Astellas: Research Funding; Celator: Research Funding; Sunesis: Consultancy, Honoraria, Other: Travel, Accomodations, Expenses, Research Funding; Agios: Research Funding; Bayer: Research Funding; Incyte: Research Funding. Gerber:Seattle Genetics: Membership on an entity's Board of Directors or advisory committees; Spectrum: Membership on an entity's Board of Directors or advisory committees; Alexion: Membership on an entity's Board of Directors or advisory committees; Janssen: Research Funding. Grunwald:Medtronic: Equity Ownership; Incyte Corporation: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Alexion: Membership on an entity's Board of Directors or advisory committees; Ariad: Membership on an entity's Board of Directors or advisory committees; Forma Therapeutics: Research Funding; Amgen: Research Funding; Janssen: Research Funding. Kota:Pfizer: Membership on an entity's Board of Directors or advisory committees; Ariad Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Leukemia Lymphoma Society: Research Funding; Incyte: Membership on an entity's Board of Directors or advisory committees.

Examining the Clinical Features and Underlying Cardiovascular Risk Among Patients with Polycythemia Vera in the REVEAL Study

Background:Patients with polycythemia vera (PV) often present with a broad range of clinical characteristics that may contribute to increased risks of cardiovascular (CV) morbidity and mortality, including thrombotic events (TE). Limited contemporary real-world data have been reported about the clinical burden of PV and treatment patterns in the United States. The ongoing REVEAL study collects data on disease burden, clinical management, patient-reported outcomes, and healthcare resource utilization for patients with PV in the United States. This analysis reports clinical characteristics, including underlying CV risk factors, for patients enrolled in the REVEAL study as of April 28, 2016.Methods: REVEAL is a multicenter, nonrandomized, prospective, observational study enrolling patients ≥18 years of age with a PV diagnosis who are actively managed in an academic or community setting. For this analysis, data regarding PV disease and diagnosis, clinical characteristics, and treatment patterns were collected at enrollment during usual-care visits and were based on physician assessment, electronic medical records, and local laboratory values. Ten-year CV risk factors selected for this analysis were adapted from the Framingham Heart Study for CV diseases.Results: At data cutoff, 2307 patients were available for this analysis. Mean (SD) age was 66.3 (12.2) years, 54.4% were male, 89.9% were white, 62.7% had at least some college education, and 51.1% were retired. Approximately 6% of patients had a family history of PV, primarily in parents (35.1%) and siblings (33.8%). A history of second malignancies was reported for 344 patients (14.9%). The majority of patients (84.6%) were diagnosed with PV based on an abnormal blood test alone or in combination with a bone marrow test. Among patients who were diagnosed with a mutational test (n=1078), 95.2% were diagnosed via an abnormal JAK2V617F test result. Abnormal hemoglobin (57.3%), hematocrit (55.4%), or both (47.5%) were among the most common blood values assessed for PV diagnosis. At diagnosis, 58.5% of patients were classified with high-risk PV (age ≥60 years or history of a TE); this percentage increased to 77.3% at REVEAL enrollment. The average (SD) disease duration from diagnosis to enrollment was 5.8 (6.1) years. At enrollment, 91.5% of patients were under active management for PV (phlebotomy ± aspirin, 34.0%; hydroxyurea ± aspirin, 27.0%; and phlebotomy + hydroxyurea ± aspirin, 23.2%). Underlying CV risk factors that were either diagnosed or treated in 86.0% of enrolled patients included hypertension (66.5%), history of smoking (46.2%), current smoking at enrollment (10.9%), obesity (34.2%), hyperlipidemia (27.4%), and diabetes (14.8%). At enrollment, 431 (18.7%) patients reported having ≥1 TE, including 181 patients who had a TE between PV diagnosis and enrollment. Venous and arterial TEs were reported in 11.1% and 8.6% of patients, respectively. Most commonly reported venous TEs were deep vein thrombosis (5.9%) and pulmonary embolism (2.5%); most common arterial TEs were cerebrovascular arterial thrombosis including transient ischemic attack (5.1%) and acute myocardial infarction (1.7%). Increased rates of TEs were observed among patients with hyperlipidemia (23.6%) and hypertension (21.0%; Table 1), compared with patients who did not have any risk factors (10.5%).Conclusion: A large proportion of patients in the REVEAL study had 1 or more underlying CV risks, including age, hypertension, smoking, obesity, hyperlipidemia, and diabetes, which may contribute to the risk of thrombosis. Longitudinal data from REVEAL will provide a better understanding of how these factors affect CV outcomes over time. [Display omitted] DisclosuresStein:Incyte Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding. Naim:Incyte Corporation: Employment, Equity Ownership. Grunwald:Janssen: Research Funding; Forma Therapeutics: Research Funding; Medtronic: Equity Ownership; Alexion: Membership on an entity's Board of Directors or advisory committees; Ariad: Membership on an entity's Board of Directors or advisory committees; Amgen: Research Funding; Incyte Corporation: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Oh:Incyte Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Research Funding; CTI: Research Funding. Paranagama:Incyte Corporation: Employment, Equity Ownership. Cordaro:Incyte Corporation: Employment, Equity Ownership. Sun:Incyte Corporation: Employment, Equity Ownership. Parasuraman:Incyte Corporation: Employment, Equity Ownership. Boccia:Celgene: Consultancy, Honoraria, Speakers Bureau; Amgen/Onyx: Consultancy, Honoraria, Speakers Bureau; Gilead: Speakers Bureau; Genentech: Consultancy, Honoraria, Speakers Bureau; Eisai: Consultancy, Honoraria, Speakers Bureau. Mesa:Ariad: Consultancy; CTI: Research Funding; Gilead: Research Funding; Galena: Consultancy; Novartis: Consultancy; Promedior: Research Funding; Celgene: Research Funding; Incyte Corporation: Research Funding.

A Novel Approach to Identify a Putative Leukemia Stem Cell Population in Acute Lymphocytic Leukemia (ALL) and Distinguish Philadelphia Chromosome-Positive ALL from Lymphoid Blast Crisis Chronic Myeloid Leukemia

Introduction: Recent evidence supports the clinical significance of leukemia stem cells (LSCs) in acute myeloid leukemia (AML). However, the identification of LSCs in acute lymphocytic leukemia (ALL) has proved challenging, as transplantation studies in immunocompromised mice have yielded conflicting results. The distinction between Philadelphia chromosome-positive (Ph+) ALL and lymphoid blast crisis (LBC) chronic myeloid leukemia (CML) is also controversial. We previously identified a clinically relevant CD34+CD38- population of LSCs with intermediate (int) levels of aldehyde dehydrogenase (ALDH) activity (CD34+CD38-ALDHint) in AML [Gerber, et al. Blood, 2012]. This population was not present in healthy controls and could be distinguished from normal hematopoietic stem cells (HSCs), which had higher levels of ALDH activity (CD34+CD38-ALDHhigh). We hypothesized that the same approach could be used to identify a putative LSC population in ALL. Furthermore, in contrast to most cases of AML, the chronic phase CML stem cell was found to reside in the same CD34+CD38-ALDHhigh population as normal HSCs [Gerber, et al. Am J Hematol, 2011]. We therefore also hypothesized that the presence of BCR/ABL mutations in the CD34+CD38-ALDHhigh population might help distinguish LBC CML from Ph+ ALL.Methods: Bone marrow and/or peripheral blood specimens were collected at diagnosis from patients with B cell ALL or LBC CML on an IRB-approved protocol. A total of 7 patients were evaluated: 2 Ph- ALL, 2 Ph+ ALL, and 3 LBC CML patients. CD34+ cells were isolated by magnetic bead and column selection, then analyzed by flow cytometry with respect to CD38 expression and ALDH activity. Sorted cell populations were analyzed by fluorescence in situ hybridization (FISH) for leukemia-specific abnormalities. Polymerase chain reaction was performed on clinical samples to determine the presence of a p190 vs. p210 transcript.Results: All patients harbored an aberrant CD34+CD38-ALDHint population, similar to that previously seen in AML. This population was ≥95% positive for BCR/ABL by FISH in all Ph+ ALL and LBC CML cases. It was similarly positive (≥75%) for other leukemia-specific FISH abnormalities (including trisomy 4, 8, 10, 12, and/or 21) in all four ALL cases, as well as one LBC CML case. Conversely, the CD34+CD38-ALDHhigh population (which typically contains the normal HSCs) lacked any of the other cytogenetic abnormalities in all of the cases, irrespective of Ph status or a diagnosis of ALL vs. CML. Notably, the CD34+CD38-ALDHhigh population was negative for BCR/ABL in the Ph+ ALL cases but was >95% positive for BCR/ABL by FISH in the LBC CML cases. The B cell differentiation marker, CD19, was expressed on the CD34+CD38-ALDHint but not the CD34+CD38-ALDHhigh population in all ALL cases, both Ph- and Ph+. In contrast, CD19 expression was variable in the LBC CML cases. Both Ph+ ALL cases possessed a p190 BCR/ABL transcript, whereas all of the LBC CML cases contained a p210 transcript. Also of note, the CD34+CD38-ALDHint population was persistently detectable in one of the LBC CML patients while in complete remission after induction therapy; that patient subsequently relapsed.Conclusions: An abnormal CD34+CD38-ALDHint population was identified in all cases of B cell ALL and LBC CML. This population is analogous to a previously identified, clinically relevant LSC population in AML and may represent a putative LSC population in ALL. The CD34+CD38-ALDHhigh population was normal by FISH in the ALL cases but contained the BCR/ABL mutation in the LBC CML cases, thus permitting distinction between Ph+ ALL and LBC CML (which also differed based on the presence of p190 vs. p210 transcripts, respectively). Additionally, clonal evolution from chronic phase to lymphoid blast crisis CML was apparent, based on the acquisition of additional cytogenetic abnormalities unique to the CD34+CD38-ALDHint population as compared to the CD34+CD38-ALDHhigh population. The presence of CD19 on the putative LSCs in the four cases of ALL suggest that CD19-directed therapies may target the LSCs and thus may have curative potential in those cases. This assay may serve as a means to evaluate other possible therapeutic targets. Lastly, the detection of the abnormal CD34+CD38-ALDHint population may have utility as a minimal residual disease assay for monitoring response to treatment. These findings warrant validation in a larger patient cohort. DisclosuresGerber:Janssen: Research Funding; Alexion: Membership on an entity's Board of Directors or advisory committees; Spectrum: Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees. Grunwald:Alexion: Membership on an entity's Board of Directors or advisory committees; Amgen: Research Funding; Incyte Corporation: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Medtronic: Equity Ownership; Janssen: Research Funding; Ariad: Membership on an entity's Board of Directors or advisory committees; Forma Therapeutics: Research Funding. Avalos:Seattle Genetics: Membership on an entity's Board of Directors or advisory committees.

Phase I Trial of Targeted Alpha-Particle Therapy with Actinium-225 (225Ac)-Lintuzumab and Low-Dose Cytarabine (LDAC) in Patients Age 60 or Older with Untreated Acute Myeloid Leukemia (AML)

Background:225Ac-lintuzumab is a radioimmunoconjugate composed of 225Ac (t½=10 days), which emits 4 α-particles, linked to a humanized anti-CD33 monoclonal antibody. Short-ranged (50-80 µm), high-energy (~100 keV/µm) α particle-emitting isotopes such as 225Ac may result in more specific tumor cell kill and less damage to normal tissues than β-emitters. An initial phase I trial in 20 patients with relapsed/refractory AML showed that a single infusion of 225Ac-lintuzumab is safe at doses ≤ 3 µCi/kg and has anti-leukemic activity (Jurcic et al. ASH, 2011). We conducted a multicenter, phase I dose-escalation trial to determine the maximum tolerated dose (MTD), toxicity, and biological activity of fractionated-dose 225Ac-lintuzumab in combination with LDAC.Patients and Methods: Patients ≥ 60 years with untreated AML not candidates for standard induction therapy (e.g., antecedent hematologic disorder, poor-risk cytogenetic or molecular features, and significant comorbidities) were eligible. Patients received LDAC 20 mg twice a day for 10 days every 4-6 weeks for up to 12 cycles. During Cycle 1, 2 fractions of 225Ac-lintuzumab were given 1 week apart, beginning 4-7 days following completion of LDAC. To prevent radiation-induced nephrotoxicity, patients were given furosemide while receiving 225Ac-lintuzumab then spironolactone for 1 year afterward. Four dose levels of 225Ac-lintuzumab were studied using a 3+3 design. Dose escalation proceeded if < 33% of patients in a cohort experienced dose-limiting toxicity (DLT).Results: Eighteen patients (median age, 77 years; range, 68-87 years) completed therapy. Twelve (67%) had prior myelodysplastic syndrome (MDS), for which 10 (83%) received therapy with hypomethylating agents (n=9) or allogeneic hematopoietic cell transplantation (n=1). One patient (6%) had chronic myeloid leukemia in molecular remission prior to developing AML. Eleven patients (61%) had intermediate-risk and 7 (39%) had poor-risk disease by NCCN criteria. Median CD33 expression was 81% (range, 30-100%). 225Ac-lintuzumab was given at 0.5 (n=3), 1 (n=6), 1.5 (n=3), or 2 (n=6) μCi/kg/fraction. Up to 4 cycles of LDAC were administered. Two patients experienced DLT (grade 4 thrombocytopenia with marrow aplasia for > 6 weeks following therapy), one each in the 1 and 2 µCi/kg/fraction cohorts. Although the MTD was not reached, 2 µCi/kg/fraction was chosen as the phase II dose to limit prolonged myelosuppression. Hematologic toxicities included grade 4 neutropenia (n=5) and thrombocytopenia (n=9). Grade 3/4 non-hematologic toxicities included febrile neutropenia (n=6), pneumonia (n=5), other infections (n=3), atrial fibrillation/syncope (n=1), transient creatinine increase (n=1), generalized fatigue (n=1), hypokalemia (n=1), mucositis (n=1), and rectal hemorrhage (n=1). Thirty- and 60-day mortality rates were 0% and 17%, respectively. Eleven of 14 patients (79%) evaluated after Cycle 1 had bone marrow blast reductions (mean reduction, 66%; range, 19-100%). Objective responses (2 CR, 1 CRp, 2 CRi) were seen in 5 of the 18 patients (28%), but only at doses ≥ 1 µCi/kg/fraction (Table 1). One of the responders received 15 cycles of azacitidine for prior MDS. All responses occurred after 1 cycle of therapy, in contrast to historical data with LDAC alone, where the median time to response was 3 cycles. Median progression-free survival (PFS) for all patients was 2.7 months (range, 1.0-31.8+ months). Median overall survival (OS) was 5.6 months (range, 1.6-32+ months). Median response duration was 5.6 months (range, 4.9-32+ months). Peripheral blood blast counts were a strong predictor of response. Among 38 patients treated in the current and initial phase I trials, responses were seen in 8 of 19 patients (42%) with blast counts < 200/µL, compared with 0 of 17 patients with blast counts ≥ 200/µL (P=0.002). This difference is likely due to decreased marrow targeting in patients with higher circulating blast counts when the subsaturating antibody doses used in this trial are given.Conclusions: Fractionated-dose 225Ac-linutuzmab can be safely combined with LDAC and induce remission in older patients with untreated AML. A phase II trial of 225Ac-lintuzumab monotherapy at 2 µCi/kg/fraction using hydroxyurea, if needed, to lower peripheral blast counts prior toadministration will be undertaken to determine response rate, PFS, and OS in this patient population. [Display omitted] DisclosuresJurcic:Forma Therapeutics: Research Funding; Seattle Genetics: Research Funding; Kura Oncology: Research Funding; Celgene: Research Funding; Novartis: Membership on an entity’s Board of Directors or advisory committees; Bayer: Consultancy; Alexion Pharmaceuticals: Consultancy; Merck & Co.: Consultancy; Astellas: Research Funding; Actinium Pharmaceuticals, Inc.: Research Funding; Daiichi-Sankyo: Research Funding. Levy:Janssen: Speakers Bureau; Actinium Pharmaceuticals, Inc.: Research Funding; Seattle Genetics: Research Funding; Amgen: Speakers Bureau; Takeda Pharmaceuticals International Co.: Speakers Bureau. Park:Amgen: Consultancy; Genentech/Roche: Research Funding; Juno Therapeutics: Consultancy, Research Funding. Ravandi:Actinium Pharmaceuticals, Inc.: Research Funding. Perl:Actinium Pharmaceuticals, Inc.: Research Funding; Seattle Genetics: Consultancy. Smith:Actinium Pharmaceuticals, Inc.: Research Funding. Cicic:Actinium Pharmaceuticals, Inc.: Employment, Equity Ownership. Scheinberg:Actinium Pharmaceuticals, Inc.: Equity Ownership, Patents & Royalties: Ac-225-Lintuzumab.

Results of an Ongoing Phase 2 Study of Brentuximab Vedotin with Rchp As Frontline Therapy in Patients with High-Intermediate/High-Risk Diffuse Large B Cell Lymphoma (DLBCL)

Results of an Ongoing Phase 2 Study of Brentuximab Vedotin with Rchp As Frontline Therapy in Patients with High-Intermediate/High-Risk Diffuse Large B Cell Lymphoma (DLBCL)

Establishment of Subspecialized Care in Hematologic Malignancies and a Hematopoietic Cell Transplantation Program

Establishment of Subspecialized Care in Hematologic Malignancies and a Hematopoietic Cell Transplantation Program

A Prospective Multi-Center Trial Shows Reduction of Early Deaths (ED) and Improved Survival in Elderly Acute Promyelocytic Leukemia (APL) Patients (>60 years). Results of Using a Simplified Treatment Algorithm and Expert Support in Georgia, South Carolina and Neighboring States

Background: APL is the most curable leukemia with reported survival above 90% in many large co-operative group studies. These excellent outcomes are not seen in elderly patients where early deaths in trials are 10-18%. Population based registry data shows that ED rate in elderly APL patients is even higher with reported incidence of 24-50%. We conducted a prospective trial using a set of simplified treatment guidelines along with support from a dedicated team of APL experts. Herein, we report outcomes of patients >60 years treated within the prospective trial. We compared these to our institutional experience prior to implementation of the trial. Methods: The protocol consisted of a two page simplified treatment algorithm with emphasis on preventing bleeding, infection and differentiation syndrome (DS); the most common causes of ED. A network of Leukemia treatment centers was established by visiting most of the leukemia treatment centers in Georgia, South Carolina and neighboring states. Communication was established between the treating community oncologist and APL expert early in the diagnosis and was continued until the end of induction. Five other large leukemia treating centers in Georgia and South Carolina were part of the study and IRB approval was obtained. After 6 months of intense publicity, the study was implemented in 7/2013 and patients were prospectively accrued. Induction deaths of elderly APL patients in our study were compared to historical results at our institution (with IRB approval for retrospective review) prior to the initiation of this program. The study was funded by the Leukemia Lymphoma Society. Statistics are descriptive. Results: Between 1/2007 and 5/2016, we treated or co-managed a total of 70 patients above the age of 60 years. 23 were in the early group (EG) and 47 after 7/2013 in the new group (NG). Comparing the EG and NG patients, median age was 66 years (range 61-80) vs 69 (61-83 years), median WBC was 1.9 vs 2.3/mm3 (range 0.3-132 vs 0.3-38), male to female ratio was 1:2 and 1:1 respectively. Risk stratification based on WBC counts at presentation (> vs Conclusions: By our observation, elderly patients tolerate full doses of ATRA and ATO poorly during induction. ATRA/ATO at reduced doses is better tolerated and use of a simplified treatment algorithm with expert support has the potential to decrease induction mortality (13.3%) and improve population wide survival (77.8%) (1 year survival in patients >60 years based on Swedish Registry data ~ 37%) in elderly APL patients. Disclosures Kota:Leukemia Lymphoma Society: Research Funding; Ariad Pharmaceuticals: Membership on an entity9s Board of Directors or advisory committees; Incyte: Membership on an entity9s Board of Directors or advisory committees; Pfizer: Membership on an entity9s Board of Directors or advisory committees. Heffner:Millennium: Research Funding; AbbVie: Research Funding; Pharmacyclics: Research Funding; Celgene: Research Funding. Stuart:Bayer: Research Funding; Celator: Research Funding; Incyte: Research Funding; Agios: Research Funding; Sunesis: Consultancy, Honoraria, Other: Travel, Accomodations, Expenses, Research Funding; Astellas: Research Funding. Gerber:Spectrum: Membership on an entity9s Board of Directors or advisory committees; Janssen: Research Funding; Alexion: Membership on an entity9s Board of Directors or advisory committees; Seattle Genetics: Membership on an entity9s Board of Directors or advisory committees. Grunwald:Forma Therapeutics: Research Funding; Medtronic: Equity Ownership; Ariad: Membership on an entity9s Board of Directors or advisory committees; Janssen: Research Funding; Alexion: Membership on an entity9s Board of Directors or advisory committees; Amgen: Research Funding; Incyte Corporation: Consultancy, Membership on an entity9s Board of Directors or advisory committees, Research Funding. Jillella:Leukemia Lymphoma Society: Research Funding.

RNA Polymerase I Inhibition with CX-5461 As a Novel Strategy to Target MYC in Multiple Myeloma

Background: The role of dysregulation of the proto-oncogene MYC in both early and late myeloma progression events is well established. Among key MYC -downstream targets is upregulation of ribosomal biogenesis, resulting in increased protein translational capacity and biomass accumulation that is characteristic of neoplastic cells. Thus, given the relationship between myeloma pathobiology, MYC dysregulation, and ribosomal biogenesis, we hypothesized that selective targeting of ribosomal RNA (rRNA) transcription with the small molecule RNA polymerase (pol) I inhibitor CX-5461 (Senhwa Biosciences) may represent a novel therapeutic strategy in myeloma.Methods: Studies with CX-5461 were performed in human myeloma cell lines, isogenic p53 wild-type (wt) and knock-out (KO) p53 cells generated using sequence-specific zinc-finger nucleases, drug-resistant cell lines, primary patient samples, and myeloma murine xenograft models using NOD-SCID IL2Rgnull mice.Results: CX-5461 treatment of p53 wt (MM1.S, MOLP-8) and p53 mutant (U266, RPMI-8226) myeloma cell lines demonstrated a time- and dose-dependent decrease in cell proliferation with a median inhibitory concentration (IC50) at nM levels after 72 hours. A corresponding increase in cleaved-PARP, cleaved caspase-9, and cleaved caspase-3 expression was seen on Western blot as well as increased Annexin V staining on flow cytometry analysis, although this was more pronounced in p53 wt versus mutant cell lines. CX-5461 also retained activity in a panel of cell lines resistant to standard myeloma therapeutic agents (bortezomib, carfilzomib, lenalidomide, and doxorubicin) and in primary patient samples, including a heavily pretreated relapsed/refractory patient and a de novo plasma cell leukemia patient with del 17p. In vivo studies using a systemic isogenic MM1.S p53 wt and KO myeloma murine xenograft model demonstrated significant improvement in median overall survival in the CX-5461-treated p53 wt cohort (41 days vs. not reached, P .05), although outcomes were more modest in the p53 KO cohort with only a trend towards improved survival (P.1) in the drug-treated mice.To probe the p53-independent effects of CX-5461, gene expression profiling and gene set enrichment analysis was performed on isogenic MM1.S and MOLP-8 p53 wt and KO myeloma cell lines treated with CX-5461 or vehicle. These results suggested downregulation of MYC downstream targets as one p53-independent effect of RNA pol I inhibition. qPCR and Western blot studies revealed rapid downregulation of MYC at the transcript level within 1-hour of CX-5461 treatment followed by decreases in MYC protein levels.Previous studies have suggested ribosomal biogenesis is tightly controlled by an auto-regulatory feedback mechanism in which ribosomal proteins such as RPL5 and RPL11 can bind to the 3'UTR of MYC mRNA and facilitate its degradation through the RNA-induced silencing complex (RISC). Because RNA pol I inhibition is known to induce a nucleolar stress response and increase the availability of free ribosomal proteins, RISC-mediated degradation of MYC mRNA was explored as one possible mechanism of CX-5461-mediated MYC downregulation. Indeed, treatment with CX-5461 led to increased pull-down of RPL5 when immunoprecipitated with the RISC subunit TAR (HIV-1) RNA Binding Protein 2 (TARBP2) compared to vehicle-treated controls, and RNA immunoprecipitation assays with the catalytic RISC subunit, Argonaute 2 (AGO2), demonstrated enrichment of MYC mRNA with CX-5461 treatment. These results suggest that CX-5461 may induce degradation of MYC through the cooperative binding of ribosomal proteins, RISC subunits, and MYC mRNA.Finally, to evaluate the role of MYC expression and ribosomal biogenesis in relation to CX-5461 sensitivity, MYC was overexpressed in the H1112 myeloma cell line, which at baseline does not harbor a MYC translocation. MYC overexpression in H1112pCDH-myc cells led to increased basal pre-rRNA transcript levels compared to H1112pCDH cells, and furthermore, led to enhanced sensitivity to CX-5461.Conclusion: RNA pol I inhibition by CX-5461 is a promising target in myeloma therapy, with downregulation of MYC representing one mechanism of action. Moreover, increased MYC expression enhances sensitivity to CX-5461, providing rationale for the clinical translation of CX-5461 for the treatment of myeloma and other MYC-driven cancers. DisclosuresO'Brien:Senhwa Biosciences, Inc.: Employment. Keats:Translational Genomic Research Institute: Employment. Orlowski:Bristol-Myers Squibb: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Spectrum Pharmaceuticals: Research Funding; Janssen Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Acetylon: Membership on an entity's Board of Directors or advisory committees; Onyx Pharmaceuticals: Consultancy, Research Funding; Millennium Pharmaceuticals: Consultancy, Research Funding; Forma Therapeutics: Consultancy; Genentech: Consultancy; BioTheryX, Inc.: Membership on an entity's Board of Directors or advisory committees; Array BioPharma: Consultancy, Research Funding.

Ricolinostat (ACY-1215), the First Selective HDAC6 Inhibitor, in Combination with Bortezomib and Dexamethasone in Patients with Relapsed or Relapsed-and-Refractory Multiple Myeloma: Phase 1b Results (ACY-100 Study)

Ricolinostat (ACY-1215), the First Selective HDAC6 Inhibitor, in Combination with Bortezomib and Dexamethasone in Patients with Relapsed or Relapsed-and-Refractory Multiple Myeloma: Phase 1b Results (ACY-100 Study)

Proteolytic Targeting Chimeric Molecules (PROTACs) Specific for Bromodomain-Containing Protein (BRD) 4 Are Active Against Pre-Clinical Models of Multiple Myeloma

Background:BRD4, a bromodomain and extraterminal domain (BET) family member, has an important role in modulating the expression of essential oncogenes such as c-MYC, and is emerged as a promising therapeutic target in diverse cancer types. Pharmacologic BET inhibitors in development such as JQ1 and OTX015 display preclinical anti-myeloma activity, and induce preferential loss of BRD4 bound to super-enhancers leading to transcriptional repression of c-MYC. Another approach to target this pathway is through the use of bi-functional molecules, which incorporate a small molecule BRD4 binding moiety with an E3 ubiquitin ligase recognition motif, such as ARV-825 and dBET1 (Lu et al. Chem Biol. 22:755, 2015, Winter et al. Science 348:1376, 2015). These agents induce Cereblon (CRBN)-dependent BRD4 ubiquitination and then proteasome-mediated degradation, thereby also reducing downstream c-MYC protein levels.Methods:We performed pre-clinical studies in myeloma cell lines and primary samples using ARV-825 and ARV-763, which are PROTACs that target BRD4 to either the CRBN or the Von Hippel-Lindau (VHL) E3 ligases, respectively. Downstream effects were studied using viability and apoptosis assays, cell cycle profiling, and Western blotting, among others.Results:Tetrazolium assays showed that both PROTACs were able to reduce the viability of a panel of myeloma cell lines, including MM1.S, U266, RPMI 8226, ANBL-6, KAS-6/1, and OPM-2 cells, and this occurred with greater potency than was the case for the BRD4 inhibitors JQ1 or OTX015. Median inhibitory concentrations were 5.66-91.98 nM for ARV-825, and 13.22-1522 nM for ARV-763, respectively. This reduction in viability was both time- and concentration-dependent, and was associated with a reduction of cells in the S phase, and an increase in G0/G1 cells, as well as cells with sub-G0/G1 DNA content, suggesting the onset of apoptosis. Programmed cell death was indeed found to be induced based on the appearance of an increase in Annexin V-positive cells by flow cytometry, and in cleaved caspase 8, caspase 9, caspase 3, and poly-ADP-ribose polymerase by Western blotting. The latter was associated with a specific reduction in the expression levels of both BRD4 and c-MYC that did not influence the abundance of other cellular proteins that were not BRD4 targets, and in a reduction in BRD4 and c-MYC mRNA. In contrast, JQ1 and OTX015 exposure resulted in a slight increase in BRD4 protein expression and a lesser decrease of c-MYC protein. Studies of drug combinations showed that, as expected, lenalidomide and pomalidomide were antagonistic to the effects of the CRBN-targeted ARV-825 PROTAC, but these immunomodulatory drugs showed additive or synergistic effects in combination with the VHL-targeted agent ARV-763. Also as expected, bortezomib and carfilzomib reduced the ability of both ARV-825 and ARV-763 to induce BRD4 degradation, but enhanced anti-proliferative and pro-apoptotic effects were seen in a manner that was influenced by the sequence of drug addition. In studies of drug-resistant cell lines, both PROTACs were able to overcome dexamethasone, melphalan, lenalidomide, and bortezomib resistance, but cross-resistance was seen in RPMI 8226/Dox40 cells, suggesting that these compounds are substrates for P-glycoprotein, which is over-expressed in these cells. Finally, we tested BRD4 PROTACs in primary cells isolated from patients with multiple myeloma, and observed rapid loss of viability of these plasma cells.Conclusions:Taken together, our data demonstrate that BRD4 degraders have promising activity against pre-clinical models of multiple myeloma, and support their translation to the clinic for patients with relapsed/refractory disease. Additional combination and mechanistic studies, as well as data from ongoing in vivo studies, will be presented at the meeting. DisclosuresLu:Arvinas, LLC: Employment, Equity Ownership. Qian:Arvinas, LLC: Employment, Equity Ownership. Orlowski:Acetylon: Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Consultancy, Research Funding; Forma Therapeutics: Consultancy; Celgene: Consultancy, Research Funding; Millennium Pharmaceuticals: Consultancy, Research Funding; Array BioPharma: Consultancy, Research Funding; Onyx Pharmaceuticals: Consultancy, Research Funding; Janssen Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Genentech: Consultancy; BioTheryX, Inc.: Membership on an entity's Board of Directors or advisory committees; Spectrum Pharmaceuticals: Research Funding.

Phase 1 Study of the Novel Kinesin Spindle Protein Inhibitor Filanesib + Carfilzomib in Patients with Relapsed and/or Refractory Multiple Myeloma (RRMM)

Phase 1 Study of the Novel Kinesin Spindle Protein Inhibitor Filanesib + Carfilzomib in Patients with Relapsed and/or Refractory Multiple Myeloma (RRMM)

Bortezomib, Lenalidomide and Dexamethasone Vs. Lenalidomide and Dexamethasone in Patients (Pts) with Previously Untreated Multiple Myeloma without an Intent for Immediate Autologous Stem Cell Transplant (ASCT): Results of the Randomized Phase III Trial SWOG S0777

Background: Lenalidomide with dexamethasone (Rd) is a standard of care for patients with previously untreated multiple myeloma. SWOG S0777, a randomized phase III trial, has compared Rd with bortezomib, lenalidomide and dexamethasone (VRd). The primary end point is progression-free survival (PFS) using a pre-specified one-sided stratified log rank test at a significance level of 0.02. The stratification factors are International Staging System (ISS) stage (I, II or III) and intent to transplant (yes or no), a total of 6 strata. Overall response rate (ORR), overall survival (OS) and safety are secondary end points. Methods: This analysis includes 474 patients evaluable for survival endpoints: 232 patients were randomized to Rd and 242 patients to VRd. Rd patients received lenalidomide 25 mg/day on days 1-21 and dexamethasone 40 mg/day on days 1, 8, 15 and 22 of a 28-day cycle. VRd patients received lenalidomide 25 mg/day on days 1-14 and dexamethasone 20/mg/day on days 1, 2, 4, 5, 8, 9, 11 and 12 plus bortezomib 1.3 mg/m 2 IV push on days 1, 4, 8 and 11 of a 21-day cycle. All patients received aspirin 325 mg/day and VRd patients received HSV prophylaxis per institutional standard. Induction was six 28-day cycles of Rd and eight 21-day cycles of VRd followed by Rd maintenance for all patients until progression, unacceptable toxicity or withdrawal of consent. Initial analyses utilized the pre-specified one-sided stratified log rank test. Results: Data are presented for VRd followed by Rd throughout. Between 2008 and 2012, 525 patients from 48 institutions were randomized. Fifty-one patients, 29 randomized to Rd and 22 randomized to RVd, were ineligible for the following reasons: missing, insufficient or early or late baseline labs (40); not meeting requirements of measurable disease (6); inadequate marrow function (1); inadequate creatinine clearance (1); prior malignancy (1); prior therapy (1); and more than 2 weeks of prior steroid therapy (1). The pre-specified significance level of 0.02 was reached in the log rank testing. The stratified hazard ratio (HR) was 0.742 (96% Wald confidence interval: 0.579, 0.951), and the one-sided stratified log rank p-value for PFS (VRd vs. Rd) was 0.0066. The OS was improved for VRd vs. Rd with HR = 0.666; two-sided log-rank p-value = 0.0114. The PFS and OS survival charts are displayed below. Median PFS was 43 months (VRd) versus 31 months (Rd). Median OS was not reached (VRd) versus 63 months (Rd). Patient characteristics were well-matched between VRd and Rd with the exception of fewer women (37% vs. 47%: P = 0.033) and fewer older patients (≥ 65 years 38% vs. 48%: P = 0.042) receiving VRd. With univariate Cox regression analysis correlates of better PFS/OS were: use of VRd (HR 0.72/0.65; P = 0.006); hemogoblin ≥10 g/dl (HR 1.17/1.43; P = 0.2/0.026) and lower ISS disease stage (HR 1.35/1.98; P = 0.014/ Conclusion: The addition of bortezomib to lenalidomide dexamethasone for induction therapy in previously untreated myeloma results in a statistically significant and clinically meaningful improvement in PFS as well as better OS. VRd had an acceptable safety and tolerability profile despite increased neurotoxicity and represents a potential new standard of care. Support: NIH/NCI/NCTN grants CA180888, CA180819, CA180821, CA180820; and in part by Millennium Pharmaceuticals, Inc., The Takeda Oncology Company, for provision of study drug. Disclosures Durie: Johnson & Johnson: Consultancy; Takeda: Consultancy; Onyx: Consultancy; Celgene: Consultancy. Abidi: Millennium: Research Funding. Epstein: University of Arkansas for Medical Sciences: Employment. Reu: Takeda/Millennium: Research Funding; Novartis: Research Funding; Celgene: Research Funding. Orlowski: BioTheryX, Inc.: Membership on an entity9s Board of Directors or advisory committees; Janssen Pharmaceuticals: Membership on an entity9s Board of Directors or advisory committees; Celgene: Consultancy, Research Funding; Spectrum Pharmaceuticals: Research Funding; Onyx Pharmaceuticals: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Millennium Pharmaceuticals: Consultancy, Research Funding; Acetylon: Membership on an entity9s Board of Directors or advisory committees; Genentech: Consultancy; Forma Therapeutics: Consultancy; Array BioPharma: Consultancy, Research Funding. Barlogie: Dana Farber Cancer Institute: Other: Travel Stipend; International Workshop on Waldenstrom9s Macroglobulinemia: Other: Travel Stipend; ComtecMed- World Congress on Controversies in Hematology: Other: Travel Stipend; European School of Haematology- International Conference on Multiple Myeloma: Other: Travel Stipend; Celgene: Consultancy, Research Funding; Millennium: Consultancy, Research Funding; Myeloma Health, LLC: Patents & Royalties: Co-inventor of patents and patent applications related to use of GEP in cancer medicine licensed to Myeloma Health, LLC; Multiple Myeloma Research Foundation: Other: Travel Stipend.

Phase I/II Trial of the Efficacy and Safety of Combination Therapy with Lenalidomide/Bortezomib/Dexamethasone (RVD) and Panobinostat in Transplant-Eligible Patients with Newly Diagnosed Multiple Myeloma

Background: Induction therapy prior to autologous stem cell transplantation (ASCT) continues to improve with the use of multi-drug combination regimens. Panobinostat (pano), a deacetylase inhibitor, was recently approved in combination with bortezomib/dexamethasone for relapsed myeloma based on the phase III PANORMA I trial for RRMM. The addition of pano in PANORAMA demonstrated a near doubling in CR rate from 15 to 27%. We previously reported phase I trial data of RVD + pano in newly diagnosed myeloma (NDMM) and demonstrated the pano can be safely combined with RVD. Based on the encouraging preliminary data we pursued a phase II dose expansion to further explore the potential improvement in depth of response with RVD + pano in NDMM.Methods: The primary objective was to determine the safety/tolerability of pano and RVD in NDMM. Secondary objectives were to determine efficacy as measured by the CR/nCR rate after 4 cycles, ORR, tolerability/toxicity, and progression free survival. Patients had to have NDMM with indication for therapy and be eligible for ASCT with adequate organ function. Panobinostat 10 mg was administered on days 1, 3, 5, 8, 10, 12; bortezomib 1.3 mg/m2 was administered subcutaneously on days 1, 4, 8, 11; lenalidomide 25 mg on days 1-14; dexamethasone 20 mg on days 1, 2, 4, 5, 8, 9, 11, and 12 on a 21 day cycle. Adverse events (AEs) were graded by NCI-CTCAE v4 and responses were assessed by the modified International Uniform Response Criteria.Results: 42 patients (pts) were enrolled; 12 in the dose escalation and 30 in the dose expansion. The median age was 60 (range 44-79); male (n=30); ISS stage I (n=28); ISS stage II (n=10); ISS stage III (n=4); 14/42 pts had high risk myeloma (1 pt with t(4:14) and del17p; 1 pt with del 17p and 1q21; and 12 pts with only 1q21 amplification).Among 42 pts, 2 completed only 1-2 cycles and 1 pt was inevaluable for response. Among the 39 pts who completed 4 cycles and were evaluable for efficacy the ORR (≥PR) after 4 cycles was 93% (36/39) including nCR/CR in 17/39 (44%), VGPR in 10/39 (26%), PR in 9/39 (23%), and SD in 3/39 (8%) pts. In 12 of 14 pts with high risk disease, who were evaluable for response, the ORR was 100% (12/12); the nCR/CR in 6/12 pts; VGPR in 4/12 pts; and 2/12 pts achieved a PR.25/42 (59%) pts completed induction therapy and underwent consolidation with ASCT; 5 pts completed induction therapy, came off study and did not proceed to ASCT. 8 pts choose a delayed transplant approach, completed induction therapy and stem cell collection. 6 of those 8 pts remain on trial with maintenance therapy (len/dex/pano) per protocol. 2 pts, neither with high risk disease, progressed after cycles 10 and 11 with extramedullary disease and plasma cell leukemia/central nervous system involvement, respectively. 4 additional patients have completed 2, 3, and 5 cycles of therapy and are pending ASCT.Grade 3-4 hematologic adverse events included anemia (5); neutropenia (10); thrombocytopenia (16). Grade 3-4 nonhematologic toxicities included ALT elevation (1); AST elevation (1); constipation (2); diarrhea (4); dyspnea (2); fatigue/muscle weakness (5); syncope (2); MI (1); nausea (3); peripheral neuropathy (2); rash (1); DVT/VTE (3).Infectious complications included grade 2 (G2) urinary tract infection (2); G2 upper respiratory tract infection (5); pneumonia (5); osteomyelitis/musculoskeletal (3); infection (3).Treatment emergent serious adverse events related to therapy observed were: G3 pneumonia (9); G2 fever (5), G3-4 venous thromboembolic events (2); G3 diarrhea (2); atrial fibrillation (2). Other events included 1 pt each with G3 cellulitis, G3 myocardial infarction (MI), G3 febrile neutropenia, G2 diarrhea, G2 seizure, G3 hypotension and G3 sinusitis. 1 pt had a second primary malignancy - a newly diagnosed breast cancer during cycle 9 of therapy.Conclusions: Panobinostat 10 mg can be safely combined with full dose RVD in NDMM. The side effect profile with use of subcutaneous bortezomib demonstrated minimal gastrointestinal toxicity/diarrhea and was a well-tolerated combination. The combination of RVD+ pano lead to rapid disease control with high response rate after 4 cycles of therapy and ORR of 93% and significant depth of response with a 4 cycle nCR/CR rate of 44%. Enrollment in dose expansion is near completion and full data will be presented at ASH and supports the study of panobinostat in a randomized trial for NDMM. DisclosuresShah:Celgene: Consultancy, Research Funding. Thomas:Celgene: Research Funding; Novartis: Research Funding; Idera Pharmaceuticals: Research Funding. Orlowski:Genentech: Consultancy; Acetylon: Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Consultancy, Research Funding; Spectrum Pharmaceuticals: Research Funding; Celgene: Consultancy, Research Funding; Array BioPharma: Consultancy, Research Funding; Janssen Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Onyx Pharmaceuticals: Consultancy, Research Funding; BioTheryX, Inc.: Membership on an entity's Board of Directors or advisory committees; Millennium Pharmaceuticals: Consultancy, Research Funding; Forma Therapeutics: Consultancy.