Phase 1 MMRC Trial of Selinexor, Carfilzomib (CFZ), and Dexamethasone (DEX) in Relapsed and Relapsed/Refractory Mul ple Myeloma
Andrzej J. Jakubowiak1, Jagoda K. Jasielec2, Cara A. Rosenbaum1, Jeffrey Zonder3, Craig E. Cole4, Ajai Chari5, Jennifer Nam1, Leonor A. Stephens1, Kathryn McDonnell1, Shaun Rosebeck1, Tami Rashal6, Hagop Youssoufian6, Sarah Henry6, Sharon Shacham6, Michael Kauffman6, Todd Zimmerman1, Theodore Karrison1 Anti-myeloma Activity of Combined Inhibition of the Proteasome(1) The University of Chicago, Chicago, IL, USA; (2) with Carfilzomib (CFZ)Northshore and University Health System, Evanston, IL, USA; (3) Karmanos Cancer Ins tute, Detroit, MI, USA; (4) University of Michigan, XPO1/CRM1-dependent Nuclear Export by Selinexor (KPTAnn Arbor, MI, USA; (5) The Mount Sinai Medical Center, New York, NY, USA; (6) Karyopharm -330) via a Novel Mechanism of Intracellular Activation of Caspase 10-dependent ApoptosisTherapeu cs Inc., Newton, MA, USA Shaun Rosebeck1, Mattina M. Alonge1, Jagoda Jasielec1, Dilara McCauley2, Sharon Shacham2, Michael Kauffman2, and Andrzej J. Jakubowiak1 1University of Chicago, Chicago, IL; 2Karyopharm Therapeutics, Newton MA INTRODUCTION RESULTS CONCLUSIONS • Exportin 1 (XPO1; also known as • Caspase 10 protease activity increases in chromosome region maintenance 1 or CRM1) Role of Caspase 10 in Selinexor/PI-induced Novel localization and association of Caspase 10 response to selinexor and CFZ treatment controls nucleo-cytoplasmic localization of cell death with autophagy machinery • Inhibition of caspase 10 activity tumor suppressor proteins (TSP) and cell suppresses activation of caspases 3, 8, proliferation/survival proteins including p53, and 9 p21, PI3K/AKT/FOXO, Wnt/β-catenin/APC, • Caspase 10 inhibition prevents 1 topoisomerase II, and NF-κB/IκBα. degradation of apoptotic targets and • We and others have demonstrated XPO1 suppresses myeloma cell death overexpression and deregulation in multiple • Untreated myeloma cell lines exhibit 2-5 myeloma (MM) , altering the localization and distribution of caspase subunits between impairing the function of TSP. soluble (pro-caspases) and • Small molecule, selective inhibitors of nuclear insoluble/membrane-associated (active export (SINE) that block XPO1-dependent caspases) subcellular fractions Active caspase nuclear export can force nuclear retention of • Combined XPO1/proteasome inhibition fragments aggregate TSP, rendering cancer cells more susceptible enhances insoluble accumulation of in the insoluble, to apoptosis and responsive to other cytotoxic active caspase fragments and cleavage 6 membrane-containing drugs , although the mechanisms are not fully of apoptotic targets understood. fraction in response to SINE/PI. • Caspase 10 co-localizes with p62 in • Autophagy recently emerged as a cell death SINE/PI-treated cells pathway and alternate to the ubiquitin • GST-p62 associates with pro-caspases proteasome pathway by which excess and/or 10 and 8 in untreated cell soluble extracts dysfunctional proteins and organelles are and binding is lost in response to degraded and recycled. combined XPO1/proteasome inhibition, • MM cells require basal autophagy for survival possibly due to accumulation of excess and Caspase 10 protease activity is required ubiquitinated targets to limit autophagic cell death.7 • We are first to demonstrate an • Previously, we demonstrated synergistic cell Figure 1: Caspase 10 activity is necessary for selinexor/CFZ-induced cell intracellular mechanism of caspase 10 death by combining the orally available death. (A) Caspase 10 protease activity and cleavage were determined from the activation and suggest a model (Figure 3) clinically staged SINE, selinexor, and the same lysates in response to the indicated treatment of MM1.S cells (*p<0.0001). wherein SINE/PI treatment increases proteasome inhibitor (PI), carfilzomib (CFZ), in (B) Relative activity of the indicated caspases was determined after combined autophagic membranes embedded with MM patient-derived plasma cells, MM cell selinexor (50 nM) and CFZ (50 nM) treatment for 24 hrs with the caspase 10 p62 and LC3 that associate with pro- 8 lines, and a murine xenograft model of MM. protease inhibitor, Q-AEVD-OPH (25 µM), where indicated. (inset) Western blot caspase 10 promoting its activation, • Our studies were the first to suggest a role for confirms inhibition of cleavage of caspase 10 and PARP from the same lysates. cleavage of other caspases and targets, both autophagy and apoptosis in response to (C) MM1.S cells were treated with the combination of selinexor and CFZ with and, subsequent apoptosis combined SINE/PI treatment. either increasing amounts of the autophagy inhibitor bafilomycin or caspase 10 • The nature of the novel intracellular OBJECTIVES inhibitor as indicated. (D) Effect of pan caspase inhibition, caspase 9 inhibition, aggregate of active caspases requires or caspase 10 inhibition on overall cell viability in MM1.S and RPMI 8226 cells further investigation • To gain insight into the molecular mechanism (*p<0.0001; **p<0.001). of synergistic myeloma cell death in response FUTURE DIRECTIONS to selinexor and CFZ The intersection of apoptosis and autophagy • “A Phase I Study of the Combination of • Explore the novel role of caspase 10 in the Selinexor and CFZ with Dexamethasone cytotoxic effects of selinexor and CFZ Figure 3: Proposed model of In Patients with Relapsed or selinexor/CFZ-induced myeloma Relapsed/Refractory Multiple Myeloma” METHODS cell death. SINE/PI-induced cell Figure 2: Novel mechanism of intracellular caspase 10 activation. (A) (NCT02199665) Cell lines, subcellular fractionation, death is associated with induction MM1.S cells were treated as indicated for 18 hrs. CHAPS detergent- • Further define molecular mechanisms of of both apoptosis and autophagy. and caspase activity assay soluble (sol.) and insoluble (insol.) fractions were analyzed for the selinexor-induced cellular effects Myeloma cell lines were grown under standard Key factors involved in autophagy, indicated proteins. (B) Indirect immunofluorescent detection of caspase LC3 and p62, may anchor pro- conditions. Subcellular fractionation was 10, caspase 8, and p62 in MM1.S cells. 100x magnification; scale bar = REFERENCES performed by resuspending cells in CHAPS lysis caspases 10 and 8, which can be 10 µm. (C) GST pull-down using either GST only or GST-p62 as bait and 1. Turner JG, Sullivan DM. Curr Med Chem (2008) activated by induced proximity, to buffer, followed by three rounds of freeze/thaw. either untreated or selinexor./CFZ-treated (18 hrs) cell lysates as input. 2. Kandarpa M, Kraftson SJ, et al. ASH Annual Meeting Soluble and insoluble fractions were separated autophagic membranes. Active (2011) by high-speed centrifugation. Insoluble pellets initiator caspases 10 and 8 3. Tiedemann RE, Zhu YX, et al. Cancer Res (2012) were washed with PBS and resuspended in an promote activation of effector ACKNOWLEDGEMENTS 4. Tai Y-T, Landesman Y, et al. Leukemia (2013) equal volume of 1x SDS loading buffer. caspases and cleave intracellular 5. Schmidt J, Braggio E, et al. Leukemia (2013) This study was supported in part by funds from the Multiple Myeloma Research 6. Turner JG, Marchion DC, et al. Cancer Res (2009) targets that promote apoptotic cell Caspase activity was assayed using colorimetric Foundation. 7. Lamy L, Ngo VN, et al. Cancer Cell (2013) substrates according to the manufacturer’s death. 8. Rosebeck S, Kandarpa M, et al. ASH Annual Meeting instructions (BioVision). (2013) Selinexor Mechanism of Ac on
• Expor n 1 (XPO1) is the major nuclear export protein for tumor suppressor proteins (TSPs) and eIF4E-bound oncoprotein mRNAs (c-myc, cyclins) • SINE compounds inhibit XPO1 à nuclear reac v- a on of TSPs and reten on of oncoprotein mRNAs à reduced c-myc and cyclin D1 levels and induc on of apoptosis selec vely in tumor cells • Selinexor is a novel oral SINE compound currently being evaluated in solid and hematological cancers including mul ple myeloma (MM)
• MM is a ra onale indica on for selinexor o XPO1 is overexpressed in MM and other hematological malignancies and its levels o en correlate with poor prognosis o Selinexor reac vates mul ple TSPs relevant to MM including p53 and FOXO and overcomes MDM2- mediated p53 degrada on o Selinexor increases IκB, which inhibits the over- ac ve NF-κB commonly found in MM o By trapping mRNAs bound to eIF4E, selinexor reduces expression of c-myc, cyclin D, MDM2 and survivin – frequently overexpressed in MM Carfilzomib Background
• Carfilzomib is a tetrapep de ketoepoxide-based proteasome inhibitor specific for the chymotrypsin- like ac ve site of the 20S proteasome. Carfilzomib is structurally and mechanis cally dis nct from the dipep de boronic acid proteasome inhibitor bortezomib. In addi on, when measured against a broad panel of proteases including metallo, aspartyl, and serine proteases, carfilzomib demonstrated less reac vity against non-proteasomal proteases when compared to bortezomib.
• Carfilzomib received approval from the Food and Drug Administra on (FDA) in July 2012 for the treatment of pa ents with mul ple myeloma who have received at least 2 prior therapies, including bortezomib and an immunomodulatory agent (IMiD) and have demonstrated disease progression on or within 60 days of comple on of the last therapy. Synergis c Ac vity in Pre-Clinical Models
A B C
Synergistic myeloma cell death after treatment with selinexor – carfilzomib combination: (A) Dose responses of HMCL treated D F with selinexor and carfilzomib for 72 hours determined by MTT assay. Combination index (CI) values at ED50 are indicated; values less than 1 indicate synergy. (B) Effects of single agent and combination treatment in tumor-bearing NOD-SCID mice implanted with NCI H929 cells subcutaneously (s.c). Treatment schedule is depicted below. (*p<0.0001) Activity of selinexor–carfilzomib combination in carfilzomib-refractory cells: (C) Two depictions of the same data: as in (A), combination dose responses in carfilzomib-resistant Dox40 cells. Selinexor is active in these cells which are cross-resistant to E both bortezomib and carfilzomib. Increased cell death by engagement of both apoptosis and autophagy: (D) Western blot analysis of MM1.S cells treated as indicated for 24 hours detecting synergistic induction of markers of both apoptosis and autophagy. (E) Western blot analysis of PC from a R/R MM patient (pt. was treated previously with BORT/Dex and LEN/Dex, transplant, then LEN maintenance; progressed; treated with and progressed on MLN, progressed on PdC Jan. 2014) treated as indicated for 24 hours. (F) Possible mechanism of caspase 10 involvement in the apoptotic machinery. Selinexor + Carfilzomib + Dexamethasone Combina on Phase I Study Design
• Selinexor + Carfilzomib + Dexamethasone Combina on o Open label, first in human evalua on of the combina on of selinexor + carfilzomib + dexamethasone: dose escala on in pa ents with relapsed or relapsed/refractory advanced MM o Modified “3+3” design, 28 day cycle o Star ng dose of selinexor 30 mg/m2 (~50 mg flat) twice weekly for three weeks (6 doses), star ng dose of carfilzomib 20/27 mg/m2 twice weekly for three weeks (6 doses), 20 mg of dexamethasone given twice weekly for four weeks (8 doses)
• Primary Objec ve o Determine the maximum tolerated dose (MTD) and the recommended phase II dose (RP2D) of the combina on of selinexor, carfilzomib, and dexamethasone in pa ents with relapsed/refractory MM
• Key Eligibility Criteria o Relapsed +/– Refractory MM with progressive disease at study entry with ≥2 prior therapies including a proteasome inhibitor and an immunomodulatory drug (IMiD) o MM refractory to carfilzomib is allowed in the escala on cohorts and is required in expansion o Measurable MM disease by IMWG Criteria o Absolute neutrophil count (ANC) ≥ 1.0 × 109/L; Hemoglobin ≥ 8 g/dL; Platelet count ≥50,000 mm3 o Adequate renal func on within 14 days prior to C1D1: es mated crea nine clearance of ≥ 30 mL/min Selinexor + Carfilzomib + Dexamethasone Combina on Dosing Scheme
A Carfilzomib and Dexamethasone Dosing
D1,2 D8,9 D15,16 D 22,23 Carfilzomib IV and Dexamethasone (A) Dosing scheme PO or IV Dose for selinexor, Week 1 Week 2 Week 3 Week 4 Dexamethasone PO or IV Dose carfilzomib, and dexamethasone Selinexor Dose combina on D1,3 D8,10 D15,17 Selinexor Dosing B Dose Carfilzomib Selinexor Dex Patients Patients Level (mg/m2) (mg/m2) (mg) Enrolled with DLTs (B) Dose levels for 1 20/27 30 20/10 5 0 selinexor, carfilzomib and dexamethasone 2a 20/36 30 20/10 3 0 and number of pa ents 2b 20/27 60* 20/10 1 0 enrolled per cohort as 3 20/36 60* 20/10 of 30-September-2015 4 20/45 60* 20/10 5 20/56 60* 20/10 *Patients enrolled in these cohorts will receive a 60 mg flat dose of selinexor Selinexor + Carfilzomib + Dexamethasone Combina on Pa ent Characteris cs
Patient Characteristic N Patient Characteristic N
2 Patients Enrolled1 9 Patients evaluable for DLT 7
Median Age (Range) 67 (55 – 73) Patients with a DLT 0
Patients ≥65 years (%) 56% Median Treatment Selinexor+Carfilzomib Cycles (Range) 4 (0.5–13)
Patients Discontinued, N (%) 6 (67%) ECOG Performance Status, 0-1 (%) 100% Discontinued due to Disease progression 6 Median Years from Diagnosis (Range) 3.6 (1.6 – 8.6) Discontinued due to Adverse Event 0 Median Prior Regimens (Range) 4 (2 – 5)
Refractory to Carfilzomib Combinations on Last Prior Discontinued due to Patient/Investigator Preference 0 7 Therapy Refractory to Carfilzomib, Pom, and Dex 5 Data cut-off as of 30-September-2015. 1All pa ents were refractory carfilzomib. 2Two pa ents required replacement for Cytogenetic risk by FISH, High : Standard (%) 44% : 56% DLT evalua on (1 pa ent had dex reduced in cycle 1 not due to DLT; 1 pa ent did not receive all scheduled cycle 1 doses due to Serum β2-microglobulin ≥3.5 mg/L (%) 44% progressive disease), both are evaluable for efficacy Selinexor + Carfilzomib + Dexamethasone Combina on Pa ent Prior Therapies
Selinexor + Carfilzomib + Dexamethasone Combination Patient Prior Therapies Patient # Prior Age Sex Prior Therapies ID Tx 1 59 F 4 Len-Dex-Transplant, Bort-Dex, Len-Dex, Carfil-Panob 2 73 F 2 Bort-Len-Dex-Tansplant+Len Maint., Pom-Carfil-Dex 3 64 F 5 Vinc-Dox-Dex, Bort-Dex, Thal-Dex-Transplant, Len-Dex, Pom-Carfil-Dex 5 70 M 5 Ixaz-Len-Dex-Transplant, Carfil-Cyclo-Dex, Carfil-Dox-Cyclo-Etop-Dex, Pom-Carfil-Dex, Carfil-Dox-Cyclo-Etop-Dex-Radiation 6 63 M 5 Melp-Bort-Pred, Cyclo-Bort-Dex, Len-Dex, Carfil, Pom-Dex 7 67 M 2 Cyclo-Bort-Pom-Dex-Transplant, Pom-Carfil-Dex 8 68 F 5 Len-Bort-Dex-Len Maint., Len-Bort-Dex-Transplant+Bort Maint., Carfil-Bort-Dex-Radiation, Carfil-Dex, ACY-1215-Pom-Dex 9 55 M 2 Len-Bort-Dex-Bort-Carfil-Dex-HdC-ASCR-Transplant, Pom-Carfil-Dex 10 68 F 3 Carfil-Len-Dex, VDT-PACE-Transplant-Cyclo-Bort-Dex+Bort-Dex Maint., Investigational-Carfil-Pom-Dex
Pa ent prior therapies listed by pa ent and treatment regimen. All pa ents have received prior carfilzomib – based treatment (and their disease became refractory to it). 7 of 9 pa ents were refractory to carfilzomib combina ons on their last line of therapy at the me of enrollment. Adverse Events (AE’s)
All grade adverse events (AEs) All Adverse Events N=9 recorded that were related to at AE Term All Grades Grade ≥3 least one of the treatment drugs Hematologic for at least 20% of the pa ent Anemia 5 (56%) 2 (22%) popula on and all Grade 3 and Lymphopenia 3 (33%) 2 (22%) Grade 4 AE’s as of 30- Thrombocytopenia 6 (67%) 6 (67%) September-2015 are shown for Neutropenia 4 (44%) 4 (44%) the nine pa ents enrolled. The Non Hematologic most common AEs reported are Fatigue 7 (78%) 2 (22%) Infection 1 (11%) 1 (11%) fa gue, gastrointes nal tract (GI) Edema 2 (22%) 1 (11%) disorders, and cytopenias, as Muscular Disorders 3 (33%) 0 (0%) an cipated in this pa ent Peripheral Neuropathy 2 (22%) 0 (0%) popula on. Cytopenias were Dyspnea 4 (44%) 1 (11%) generally observed beyond cycle Headache 2 (22%) 0 (0%) 1, however only a minority of GI Tract Disorders 8 (89%) 0 (0%) pa ents (2/9) required dose Eye Disorders 5 (56%) 0 (0%) modifica ons due to cytopenias. Confusion 1 (11%) 1 (11%) Elevated Liver Enzymes 4 (44%) 1 (11%) No unexpected AEs were Elevated Pancreatic Enzymes 2 (22%) 0 (0%) observed to date. AEs were Hyponatremia 1 (11%) 1 (11%) reversible and managed with Psychosis 1 (11%) 1 (11%) suppor ve therapy and/or dose adjustments. Clinical Ac vity
A Best Response & Time on Study
01 VGPR (91%)
02 PR (58%) (A) Best response and 03 PR (86%) me on study (in 05 months) for each 06 VGPR (97%) pa ent. Median me on study was 4 07 PR (82%) N=9 Pa5ent Number months with a range 08 MR (44%) Duration of Treatment of 0.5 – 13+ months. Off Study Due to PD 09 PR (57%) Patient Continues on Treatment 10
0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 Months
B Best Responses in Evaluable (N=9) Patients (as of 30-Sept-2015) (B) Best responses as of 30-
N CBR ORR VGPR PR MR PD Sep-2015 (IMWG criteria). The ORR Selinexor + Carfilzomib + Dexamathasone Combination (overall response rate) is 67% in 9 7 (78%) 6 (67%) 2 (22%) 4 (44%) 1 (11%) 2 (22%) these pa ents, all of whom had CBR=Clinical Benefit Response (VGPR+PR+MR), ORR=Overall Response carfilzomib/dexamethasone Rate (VGPR+PR), VGPR=Very Good Partial Response, PR=Partial refractory MM. Response, MR=Minor Response, PD=Progressive Disease. Responses as of 30-Sep-2015 based on interim unaudited data. Responses were adjudicated according to the International Myeloma Working Group criteria. Summary and Conclusions
Although s ll early, the combina on of selinexor, carfilzomib, and dexamethasone, demonstrates encouraging ac vity in these heavily pretreated pa ents : • 67% (6 out of 9) reached PR or be er as their best response • 71% (5 out of 7) pa ents refractory to carfilzomib in their last prior therapy responded to this combina on of selinexor-carfilzomib-dexamethasone • Most pa ents achieved clinically meaningful dura on of response (up to 12+ months) • There were no unexpected toxici es • Responses in pa ents with MM refractory to highly ac ve carfilzomib combina ons in the last line of therapy (e.g., Pom-Carfil-Dex) suggest that this regimen can overcome carfilzomib resistance • The study con nues to enroll to determine MTD and be er define tolerability and efficacy at MTD • Based on these results, further evalua on of this combina on in randomized se ng is warranted Acknowledgements
• We would like to thank all of the pa ents who have par cipated in this study, the inves gators, nursing staff, and research support staff in par cipa ng ins tu ons, the Mul ple Myeloma Research Consor um, under whom this mul -site trial is conducted, Onyx Pharmaceu cals, Inc, an Amgen subsidiary, and Karyopharm Therapeu cs for suppor ng the study
References
• Rosebeck, S. et al. Blood. 2013; Abstract 279, Rosebeck, S. et al. Blood. 2014; Abstract 3444 • Rosebeck, S., Alonge, M.M., Kandarpa, M., et al. Molecular Cancer Therapeu cs, Accepted