Forward-looking Statements This presentation contains forward-looking statements within the meaning of the "safe harbor" provisions of The Private Securities Litigation Reform Act of 1995. Such forward-looking statements

Corporate Presentation June 2018

Targeting Disease at the Nuclear Pore Exhibit 99.1

Forward-looking Statements This

presentation contains forward-looking statements within the meaning of the "safe harbor" provisions of The Private Securities Litigation Reform Act of 1995. Such forward-looking statements include those regarding the therapeutic

potential of and potential clinical development plans and commercialization for Karyopharm's drug candidates, including the timing of initiation of certain trials, of the reporting of data from such trials, of the submissions to regulatory

authorities and of potential commercial launches, the potential availability of accelerated approval pathways, the potential size of the markets for multiple myeloma drugs and multiple myeloma drugs for treatment of patients with relapsed multiple

myeloma and Karyopharm's strategic and financial plans and expectations as well as financial projections for Karyopharm. Such statements are subject to numerous important factors, risks and uncertainties that may cause actual events or results

to differ materially from Karyopharm's current expectations. For example, there can be no guarantee that regulators will agree that selinexor qualifies for accelerated approval in the U.S. or conditional approval in the E.U. as a result of the

data from the STORM study in patients with penta-refractory myeloma or SADAL study in patients with relapsed/refractory DLBCL or that any of Karyopharm's drug candidates, including selinexor (KPT-330) and eltanexor (KPT-8602),

Karyopharm's second generation SINE compound, or KPT-9274, Karyopharm's first-in-class oral dual inhibitor of PAK4 and NAMPT, or any other drug candidate Karyopharm is developing, will successfully complete necessary preclinical and

clinical development phases or that development of any of Karyopharm's drug candidates will continue. Further, there can be no guarantee that any positive developments in Karyopharm's drug candidate portfolio will result in stock price

appreciation. In addition, even if Karyopharm receives marketing approval for selinexor or another drug candidate, there can be no assurance that Karyopharm will be able to successfully commercialize that drug candidate. Management's

expectations and, therefore, any forward-looking statements in this presentation could also be affected by risks and uncertainties relating to a number of other factors, many of which are beyond Karyopharm's control, including the following:

Karyopharm's results of clinical trials and preclinical studies, including subsequent analysis of existing data and new data received from ongoing and future studies; the content and timing of decisions made by the FDA and other regulatory

authorities, investigational review boards at clinical trial sites and publication review bodies, including with respect to the need for additional clinical studies; the ability of Karyopharm or its third party collaborators or successors in

interest to fully perform their respective obligations under the applicable agreement and the potential future financial implications of such agreement; unplanned cash requirements and expenditures; development of drug candidates by

Karyopharm's competitors for diseases for which Karyopharm is currently developing its drug candidates; that the markets for multiple myeloma drugs will grow as predicted; and Karyopharm's ability to obtain, maintain and enforce patent

and other intellectual property protection for any drug candidates it is developing. These and other risks, including those which may impact management's expectations, are described in greater detail under the heading "Risk Factors" in

Karyopharm's Quarterly Report on Form 10-Q for the quarter ended March 31, 2018, which is on file with the SEC, and in subsequent filings filed by Karyopharm with the SEC. Any forward-looking statements contained in this presentation are for

informational purposes only and speak only as of the date hereof. Other than as is required by law, Karyopharm expressly disclaims any obligation to update any forward-looking statements, whether as a result of new information, future events or

otherwise. Karyopharm's website is http://www.karyopharm.com. Karyopharm regularly uses its website to post information regarding its business, drug development programs and governance. Karyopharm encourages investors to use

www.karyopharm.com, particularly the information in the section entitled "Investors," as a source of information about Karyopharm. References to www.karyopharm.com in this presentation are not intended to, nor shall they be deemed to,

incorporate information on www.karyopharm.com into this presentation by reference. Unless otherwise noted, this presentation contains data that are interim and unaudited based on site reports. In addition, data included in this presentation have not

been updated and are as of the cutoff date for the applicable medical conference presentation. Unless otherwise noted, all reference to market sizes are based on reports from Global Data or Karyopharm internal estimates. 2018 Karyopharm

Karyopharm Highlights Strong leadership

team and balance sheet First-in-class, oral SINE compounds Lead asset with significant commercial potential 1 Global Data, 2 Assuming positive outcome from Phase 2b SADAL study, 3 Assuming positive outcome from Phase 3 BOSTON study, 4 Assuming

positive outcome from Phase 3 portion of SEAL study Hematologic Malignancies Multiple Myeloma Diffuse Large B-cell Lymphoma Liposarcoma Gynecologic Cancers Solid Tumor Malignancies 2018 Karyopharm Therapeutics Inc. Multiple near term catalysts

from broad, late-stage pipeline Executive team with past successes in lead indications; with recent offering proceeds, cash expected to fund the company into 3Q 2019 Novel, broadly applicable mechanism of action with single agent activity and works

well in combinations; patent life through 2032+ Selinexor demonstrated robust activity in penta-refractory myeloma, is combinable with existing therapies and has the potential to be the next "backbone" therapy in myeloma, a market

projected to be $22.6B in 20231 Anticipated data readouts (2018-2019): SADAL (end of 2018), BOSTON (end of 2019; pending PFS events), SEAL (end of 2019) Regulatory Profile: Fast Track and orphan designations granted in multiple myeloma. Planned

requests for accelerated approval in multiple myeloma (2H18), accelerated approval in DLBCL (2019)2, full approval in multiple myeloma (2020)3, full approval in liposarcoma (2020)4 Preparing for potential launch of selinexor in multiple myeloma and

DLBCL in 2019, followed by expansion to other potential indications Preparing for potential product launches and revenues

All Oral Pipeline COMMERCIAL RIGHTS

Japan* Relapsed/refractory | BOSTON Relapsed/refractory | STOMP Penta-refractory | STORM 1 Oral selinexor, Velcade (bortezomib) and dexamethasone vs. Velcade and dexamethasone 2 Oral selinexor + dexamethasone 3 Oral selinexor and dexamethasone

+ Revlimid (lenalidomide), Pomalyst (pomalidomide), Velcade, Kyprolis (carfilzomib) or Darzalex (daratumumab) 4 Investigator-sponsored randomized Phase III trial 2018 Karyopharm Therapeutics Inc. AREA OF THERAPY

PRECLINICAL PHASE I PHASE II PHASE III HEMATOLOGIC MALIGNANCIES Multiple Myeloma SELINEXOR + VELCADE1 SELINEXOR2 SELINEXOR + BACKBONE THERAPIES3 Diffuse Large B-cell Lymphoma | SADAL SELINEXOR SOLID TUMOR MALIGNANCIES Liposarcoma | SEAL SELINEXOR

Endometrial Cancer | SIENDO4 SELINEXOR Glioblastoma | KING SELINEXOR ADDITIONAL ONCOLOGY PROGRAMS MDS, CRC, PrC ELTANEXOR (KPT-8602) Solid Tumors & Lymphoma KPT-9274 OTHER INDICATIONS Lymphoma in Companion Animals VERDINEXOR (KPT-335)

Relapsed/refractory | BOSTON Relapsed/refractory | STOMP Penta-refractory | STORM *Territories: Japan, S. Korea, Taiwan, Hong Kong, and ASEAN countries. ** Antengene licensed rights to selinexor and eltanexor in China and Macau. *** Antengene

licensed rights to KPT-9274 and verdinexor in mainland China, Macau, Taiwan, Hong Kong, South Korea, and the ASEAN countries. **** Anivive holds exclusive worldwide rights to research, develop and commercialize verdinexor only for the treatment of

cancer in companion animals **** Oral SINE compound and XPO1 inhibitor KPT-350 acquired by Biogen for treatment of certain neurological and neurodegenerative conditions, including ALS, in Jan 2018 China** China***

Selinexor/SINE Mechanism of Action:

Inhibition of XPO1 2018 Karyopharm Therapeutics Inc.

Selinexor: A Growing Body of Safety

Data 2,400 Total patients treated to date Favorable emerging tolerability profile; multiple ongoing Phase 3 studies Dosing regimens utilized in key Phase 2 and 3 trials (e.g., BOSTON, STORM, STOMP, SADAL and SEAL) have shown generally predictable

and manageable tolerability, particularly when used once weekly in combination regimens Common side effects are generally predictable across multiple tumor types and generally reversible and/or manageable with standard supportive care Combination

regimens have demonstrated a predictable and manageable tolerability profile, with observed additive or synergistic activity and potential to re-sensitize to prior therapies Phase 3 BOSTON selinexor regimen allows for use of 40% less Velcade

and 25% less dexamethasone than standard Velcade and dexamethasone dosing In certain trials, side effects reported from treatment arms evaluating selinexor and dexamethasone in combination with other anti-myeloma agents are similar to, or

reduced, compared to selinexor and dexamethasone alone ~48 Number of clinical trials ongoing and/or completed 2018 Karyopharm Therapeutics Inc. 1 Per ClinicalTrials.gov (as of Apr 26, 2018); 5 of 46 are company-sponsored and currently

enrolling >10 Number of cancers explored 1

Selinexor: Regulatory Strategy in

United States and Europe Multiple Myeloma FDA granted Fast Track status to selinexor in multiple myeloma and Orphan Drug Designation has been awarded to selinexor in multiple myeloma and DLBCL by FDA and EMA and in liposarcoma by FDA Fast Track

allows more frequent interaction with FDA, rolling New Drug Application (NDA) submission and ability to request priority review and accelerated approval Orphan Drug Designation in the US and EU can provide regulatory development support, tax credits

(US), reduced or waived marketing applications fees and marketing exclusivity periods Planning to utilize Fast Track benefits in submitting first NDA during the second half of 2018 based on data from the STORM study of penta-refractory myeloma EMA

submission expected to follow in early 2019 with a request for conditional approval in penta-refractory myeloma Marketing approval opportunities in multiple indications: multiple myeloma (STORM and BOSTON), DLBCL (SADAL) and liposarcoma (SEAL)

2018 Karyopharm Therapeutics Inc. DLBCL Liposarcoma

Selinexor in Hematologic Malignancies

of patients survive 5 years3 50%

Americans are currently living with MM3 120,000 Approximately people worldwide are diagnosed annually2 86,000 An estimated 30,000 people in the US are diagnosed annually1 An estimated 1 American Cancer Society 2 Becker, N. Recent Results Cancer

Res. 2011;183:25-35. doi: 10.1007/978-3-540-85772-3_2 3 National Cancer Institute Multiple Myeloma Multiple myeloma is a cancer of plasma cells. Normal plasma cells are found in the bone marrow and make antibodies that help the body attack and

kill germs1 Myeloma is characterized by low blood counts (e.g., anemia), bone and calcium problems, infections, kidney problems and light chain amyloidosis1 Myeloma is treatable, but >12,000 deaths still occur each year in the U.S.1 2018

Karyopharm Therapeutics Inc.

Planned Selinexor Development

Strategy in Multiple Myeloma 2018 Karyopharm Therapeutics Inc. Phase 2b STORM study1 addressing patients with penta-refractory2 myeloma Disease refractory to PIs, IMiDs and Darzalex Highest unmet medical need in multiple myeloma 1

Evaluating selinexor with low-dose dexamethasone. 2 Patients who have previously received two PIs, Velcade (bortezomib) and Kyprolis (carfilzomib), and two IMiDs, Revlimid (lenalidomide) and Pomalyst (pomalidomide), and their

disease is refractory to at least one PI, at least one IMiD, and their disease is also refractory to the anti-CD38 monoclonal antibody Darzalex (daratumumab), and has progressed following their most recent therapy. Pivotal Phase 3 BOSTON study

addressing patients with relapsed or refractory disease following 1-3 prior lines of therapy Selinexor combined with once-weekly Velcade Phase 1b/2 STOMP as a potential backbone therapy in combination with standard approved therapies Selinexor

and low-dose dexamethasone combined with Revlimid , Pomalyst , Velcade , Kyprolis or Darzalex Future Phase 2/3 studies in combination for labeling

Ongoing single-arm clinical trial

evaluating selinexor in combination with low-dose dexamethasone in patients2 with penta-refractory3 myeloma Selinexor received Fast Track designation from the FDA for this indication, acknowledging the unmet need STORM1: A Phase 2b Study In Myeloma

1 Selinexor Treatment of Refractory Myeloma 2 Median 7 prior regimens 3 Patients who have previously received two PIs, Velcade (bortezomib) and Kyprolis (carfilzomib), and two IMiDs, Revlimid (lenalidomide) and Pomalyst

(pomalidomide), and their disease is refractory to at least one PI, at least one IMiD, and their disease is also refractory to the anti-CD38 monoclonal antibody Darzalex (daratumumab), and has progressed following their most recent therapy

2018 Karyopharm Therapeutics Inc.

STORM: A Phase 2b Study In Myeloma

Safety: Predictable and manageable tolerability profile; results consistent with those reported previously from Part 1 of STORM and from other selinexor studies. As anticipated, the most common non-hematologic AEs were nausea, vomiting, fatigue and

reduced appetite; primarily low grade and manageable with standard supportive care and/or dose modification. The most common hematologic AEs were Grade 3 cytopenias and were generally not associated with clinical sequelae. No new safety

signals. Next steps: Plan to submit NDA to FDA during second half of 2018, requesting accelerated approval Potential for rolling NDA Plan to submit MAA to EMA in early 2019 Detailed efficacy and safety results to be submitted for presentation at an

upcoming medical oncology meeting OVERALL RESPONSE RATE1 DURATION OF RESPONSE1 25.4% 4.4 We believe selinexor is the furthest advanced agent being investigated in penta-refractory myeloma MONTHS Penta-refractory (n=122): 2018 Karyopharm

Therapeutics Inc. INCLUDING: 2 CRs 29 VGPRs or PRs 1 As confirmed by an Independent Review Committee.

Ongoing randomized, open-label

clinical trial evaluating once weekly selinexor and Velcade (bortezomib) plus low-dose dex versus standard twice-weekly Velcade plus low-dose dex in patients with relapsed or refractory MM, who have had 1-3 prior lines of therapy

BOSTON1: A Phase 3 Study In Myeloma 1 Bortezomib, Selinexor and dexamethasone 2 Pts must have achieved PR, and completed proteasome inhibitor therapy at least 60 days prior. 3 Pending PFS events. 2018 Karyopharm Therapeutics Inc.

Top-line data expected end of 20193

STOMP: A Phase 1b/2 Study In Myeloma

Selinexor + Velcade + dex (SVd)3 (n=40) Selinexor + Pomalyst + dex (SPd)2 (n=30) 1 White D, et al. ASH 2017. Abstract 1861. 2 Chen C, et al. EHA 2018. Abstract PF586. 3 Bahlis NJ, et al. EHA 2018. Abstract PS1322. 4 Patient population

eligible for Phase 3 BOSTON study. 5 Gasparetto C, et al. EHA 2018. Abstract PS1329. 6 Five of six had prior Velcade exposure. Selinexor + Revlimid + dex (SRd)1 (n=16) Selinexor + Darzalex + dex (SDd)5 (n=19) 83% ORR (Non-Refractory to

PIs) ORR 63% (All) 55% ORR (Pomalyst-Na ve and Revlimid-Relapsed or -Refractory ) ORR 50% (All) 92% ORR (Revlimid-Na ve) 82% ORR (Darzalex-Na ve) ORR 74% (All) 4 ORR 81% (All) 2018 Karyopharm Therapeutics Inc. Next steps:

Advancing into frontline setting: Initiated new arm evaluating selinexor, Revlimid and dexamethasone in patients with newly diagnosed multiple myeloma Efficacy and safety observed in SVd arm informing ongoing Phase 3 BOSTON study Plan to

report updated data from ongoing arms at future medical meetings Safety: SRd (n=19): Most common Grade 1/2 AEs were nausea, anorexia, fatigue, weight loss, constipation and vomiting; most common Grade 3 adverse events were thrombocytopenia

and neutropenia SPd (n=34): Most common Grade 1/2 AEs were anorexia, nausea, fatigue, weight loss, diarrhea and thrombocytopenia; most common Grade 3 AEs were neutropenia, thrombocytopenia and anemia SVd (n=42): Most common Grade 1/2 AEs were

nausea, anorexia, fatigue, diarrhea, vomiting and weight loss; most common Grade 3 AEs were thrombocytopenia, neutropenia, fatigue and anemia. Peripheral neuropathy across all patients was Grade 1/2 and limited to six patients (14%).6 SDd

(n=21): Most common Grade 1/2 AEs were nausea, fatigue, diarrhea, constipation and anorexia; most common Grade 3/4 AEs were thrombocytopenia, leukopenia, anemia, neutropenia and decreased lymphocyte count 17.8 PFS 11.6 PFS mos mos

FOLLOW ON 2nd LINE FOLLOW ON 3rd/4th

LINE FRONTLINE V=Velcade (bortezomib), R=Revlimid (lenalidomide), d=dexamethasone, K=Kyprolis (carfilzomib), D=Darzalex (daratumumab), SCT=Stem cell transplantation, R/R=Relapsed/refractory, P=Pomalyst (pomalidomide),

DOR=Duration of response, F=Farydak (panobinostat), M=melphalan, N=Ninlaro (ixazomib), C=cyclophosphamide, E=Empliciti (elotuzumab). 1 Global Data. 2 Internal estimate. Clinical study / Other Triplets or Quadruplets No Standard of

Care ~35% Transplant Eligible Induction VRd, KRd, DRd, Others Autologous SCT Intermediate or High Risk: Vd or Kd Maintenance Low Risk: Rd Maintenance KRd, DRd, DVd, ERd Clinical Trial Autologous SCT if prior SCT had PFS of >18 months ~65%

Transplant Ineligible VRd, Vd or Rd KRd (high risk) VMP (DVMP) (EU mainly), (DRd) Continuous treatment until progression (may move to doublet) DVd, DRd, KRd, NRd, V or N + Cd, ERd, High Kd 2018 Karyopharm Therapeutics Inc. KPd, VPd, DPd

Antibody and triplets, FVd Phase 3 BOSTON Study Phase 2b STORM Study Integration of Selinexor into the MM Landscape in 2019 and Beyond The worldwide market for multiple myeloma drugs is expected to grow from annual sales of $19.7 billion in 2018 to

$22.6 billion in 2023.1 The worldwide market for multiple myeloma drugs for treatment of patients with relapsed multiple myeloma is approximately two-thirds of the total market.2

Selinexor in Hematologic

Malignancies Diffuse Large B-Cell Lymphoma