#1ONCONOVA THERAPEUTICS International EB symposium in Osaka May 8/9 2023#2ONCONOVA THERAPEUTICS Steven Fruchtman, M.D President and CEO Onconova Therapeutics#33 Forward-looking Statements This presentation contains forward-looking statements about Onconova Therapeutics based on management's current expectations, which are subject to known and unknown uncertainties and risks. Onconova has attempted to identify forward-looking statements by terminology including "believes," "estimates," "anticipates," "expects," "plans," "intends,” “may,” “could,” “might," "should," "approximately," "preliminary," "promising," "encouraging" or other words that convey uncertainty of future events or outcomes. This presentation assumes the Company raises capital for disclosed product development plans. Our actual results could differ materially from those discussed due to a number of factors including, but not limited to, our ability to raise additional financing on favorable terms, the success of our and investigator-initiated clinical trials, our ability to obtain regulatory approvals and other risk factors outlined in our annual and quarterly reports filed with the Securities and Exchange Commission. We are providing this information as of the date of this presentation and do not undertake any obligation to update any forward-looking statements, whether written or oral, that may be made from time to time, as a result of new information, future events or otherwise except as required by law. 0 ONCONOVA THERAPEUTICS#4About Onconova Therapeutics Clinical-stage biopharmaceutical company focused on developing novel products for patients with cancer Proprietary targeted anti-cancer agents Narazaciclib: Multi-kinase inhibitor targeting CDK 4/6 and other kinases important for cell proliferation and motility Rigosertib: Targets RAS and PLK-1 pathways and is an immune modulator Public company (NASDAQ: ONTX) ง ONCONOVA THERAPEUTICS#5ONCONOVA THERAPEUTICS Rigosertib: Research & Development#6Rigosertib Interferes with Multiple Signaling Pathways 4 Plk1 inhibitor ATP-binding pocket RGS PLK1 1 Rigosertib (ON-01910.Na) RGS 5 PI3K-Akt inhibitor 2 PI3K RAS/RAF pathway inhibitor Akt RAS RGS RAF 3 6 Microtubule-destabilizing agent sistance genes RGS 00 Sensitivity genes Free */ẞ-tubulin Microtubule JNK-mediated activator K-RAS SosGEF RGS Mitotic stress MEK B-RAF P ROS C-RAF Figure adapted from Monfort-Vengut, Pharmaceutics, 2023 1: Reddy, J. Med. Chemistry, 2011 2: Athuluri-Divakar, Cell, 2016 3: Ritt, Mol. Cell, 2016 4: Atanasova, Clin. Cancer Res., 2019 5: Anderson, Mol. Cancer Ther., 2013 6: Jost, Mol. Cell, 2017 I ERK I Proliferation ↓ JNK ONCONOVA THERAPEUTICS#7Rigosertib Effect in NSCLC PDX Model Clinical Summary: Metastatic lung adenocarcinoma 53 y/o female mNSCLC KRASG12D ALK+ Volume (mm³) 1000 800 600 400 200 0 0 2 4 6 8 10 12 14 16 18 20 22 24 89.1% PD-L1+ (surface) Days Placebo-Mouse 1 Placebo-Mouse 2 Placebo-Mouse 3 Placebo-Mouse 4 Placebo-Mouse 5 7 Data on file. NSCLC: Non-small cell lung cancer RGS Placebo RGS-Mouse 1 RGS-Mouse 2 RGS-Mouse 3 RGS-Mouse 4 RGS-Mouse 5 PERK Staining PLACEBO rigosertib 0 ONCONOVA THERAPEUTICS#880 Rigosertib + HX-008 (PD-1) Act Synergistically MC38 (colorectal cancer) Tumor Model Data on file Tumor Volume (mm3) (Mean+SEM) 800 700 600 500 400 300 200 100 -Placebo -rigosertib -PD1 -PD1+RGS 0 3 6 9 12 15 18 21 Days Placebo RGS PD1 RGS+PD1 0 ONCONOVA THERAPEUTICS#9Phase 1/2a Trial: Patients Trial opened in June 2020 • 19 patients enrolled as of August 2022 95% of patients have non-G12C mutations Cohort is heavily treated - all patients progressed on prior PD1/L1 inhibitors 280mg BID 560mg AM 280mg PM 560mg BID Expansion Phase Baseline Characteristics Age in years - median (range) Type of KRAS mutation – n (%) - Cohort N=19 65 (45-80) G12V 7 (37%) G12D 5 (26%) G12C 1 (5%) G12F 1 (5%) G12A 1 (5%) G13 (D/C) 2 (11%) Other (Q61H, 146T) 2 (11%) STK11 Co-mutations 5 (26%) PDL1 Expression - n (%) 50% 4 (21%) 1-49% 7 (37%) <1% 8 (42%) Smoking history - n (%) Current/Former 15 (79%) Never 4 (21%) Prior Lines of Systemic Therapy – n (%) - 1 3 (20%) 2 9 (60%) 3 (20%) Adapted from Veluswamy et al. European Society for Medical Oncology Congress 2022. ≥ 3 ONCONOVA THERAPEUTICS#10Complete Response Extracranial CR Not Evaluable (off treatment) In Evaluation Window Efficacy Results 4 of 14 (29%) Evaluable Patients had Disease Control (1 CR + 2 PR + 1 SD) 4 of 13 (31%) above minimum clinically effective dose of rigosertib had Disease Control Subject 19 G12A Partial Response Stable Disease 18 G12V 17 G13C/STK11 16 G13D 15 G12F/STK11 14 Q61H/STK11 13 Q12D 12 G12V 560 mg BID 11 G12D 10 G12V 6 G12D 8 G12V 7 G12D 6 G12D GU Toxicity (GR 2) 5 G12V 4 G12V GU Toxicity (GR 2) 3 G12V Hyponatremia (DLT) 560 mg/280 mg 2 G12C/STK11 10 280 mg BID 1 146T/STK11 0 1 2 3 4 5 6 7 8 9 10 Months Adapted from Veluswamy et al. European Society for Medical Oncology Congress 2022. DLT: Dose limiting toxicity; CNS: Central nervous system Progressive Disease Continues on Treatment Disease Progression CNS Metastasis Best Overall Response in Evaluable Patients (N=14) Complete Response (CR) 1 (7%) Partial Response (PR) 2 (14%) Stable Disease (SD) 1 (7%) Mean Duration of Response = 6.75 months Mean Duration of Extracranial Response = TBD ONCONOVA THERAPEUTICS#11Safety/Tolerability with Rigosertib + Nivolumab Treatment related adverse events were mostly mild Urinary toxicities well documented with rigosertib were most common TRAE • TRAES were mostly mild and manageable No synergistic toxicities noted for either study drug One DLT at 560mg BID for grade 3 hyponatremia - previously documented with rigosertib Entire Cohort: N=19 Treatment-Related Adverse Events (TRAES) - n (%) Grade 1-2 Grade 3 • 10 (53) Dysuria 12 (63) Hematuria Urinary Frequency 5 (26) 6 (32) Abdominal Pain 10 (53) Fatigue 13 (68) Anemia Lymphopenia 4 (21) 1(5) 2 (11) Thrombocytopenia 2 (11) Hyponatremia* 7 (37) 1(5)* Hyperglycemia 11 (58) • AST elevation 4 (21) 1 (5)# ALT elevation 3 (16) 1 (5)# ALK elevation 6 (32) Nausea/Vomiting Constipation 5 (26) 1(5) 7 (37) 3 (16) Diarrhea 6 (32) 1(5) Anorexia Acute Kidney Injury 7 (37)^ Infusion-related Reaction 1 (5) *Dose Limiting Toxicity: #Resolved with steroids: "Resolved with IV fluids Adapted from Veluswamy et al. European Society for Medical Oncology Congress 2022. TRAE: Treatment related adverse event; DLT: Dose limiting toxicity 11 0 ONCONOVA THERAPEUTICS#12Rigosertib in Patients with Recessive Dystrophic Epidermolysis Bullosa- associated SCC Investigator initiated trials: NCT03786237: Prof. Johann Bauer, EB House Austria, University Hospital Salzburg . NCT04177498: Dr. Neda Nikbakht, Thomas Jefferson University, PA 12 ClinicalTrials.gov 0 ONCONOVA THERAPEUTICS#13Rigosertib's Promising Single-agent Activity in RDEB-associated SCC Complete remission of all cancerous skin lesions in 2 of 2 evaluable participants RDEB-associated SCC: An ultra-rare condition Lesions Display Clinical and Histological Remission Following Treatment with Rigosertib Absence of type VII collagen protein leads to extreme skin fragility and chronic wound formation Patients develop SCCs that arise in areas of chronic skin inflammation Cumulative risk of death: 78.7% by age 55 Current therapies: Limited response of short duration V25 (Day 169-175) V1 (Day 1) Left Hand Right Elbow 13 RDEB: Recessive dystrophic epidermolysis bullosa; SCC: Squamous cell carcinoma; Source: Laimer et al. Austrian Society of Dermatology and Venerology Annual Conference 2021 ง ONCONOVA THERAPEUTICS#14ONCONOVA THERAPEUTICS How was rigosertib matched with RDEB SCC? Andrew South, PhD#15Polo-like kinase-1 identified as a therapeutic target in RDEB CSCC Open ORIGINAL ARTICLE Oncogene (2011) 1 12 ©2011 Macmillan Publishers Limited All rights reserved 0950-9232/11 www.nature.com/onc Integrative mRNA profiling comparing cultured primary cells with clinical samples reveals PLK1 and C20orf20 as therapeutic targets in cutaneous squamous cell carcinoma SA Watt¹³, C Pourreyron¹³, K Purdie², C Hogan', CL Cole¹, N Foster³, N Pratt³, J-C Bourdon¹³, V Appleyard', K Murray', AM Thompson', X Mao², C Mein, L Bruckner-Tuderman³, A Evans, JA McGrath', CM Proby¹, J Foerster', IM Leigh' and AP South' 15 Oncogene. 2011 30(46):4666-77. PMID: 21602893 PMCID: PMC3219832 npg 0 ONCONOVA THERAPEUTICS#16Rigosertib identified as lead PLK1 inhibitor in RDEB CSCC Translational Cancer Mechanisms and Therapy Identification of Rigosertib for the Treatment of Recessive Dystrophic Epidermolysis Bullosa- Associated Squamous Cell Carcinoma Clinical Cancer Research Check for updates Velina S. Atanasova', Celine Pourreyron², Mehdi Farshchian', Michael Lawler', Christian A. Brown IV, Stephen A. Watt2, Sheila Wright2, Michael Warkala', Christina Guttmann-Gruber³, Josefina Piñón Hofbauer³, Ignacia Fuentes 4,5, Marco Prisco', Elham Rashidghamat, Cristina Has, Julio C. Salas-Alanis, Francis Palisson 4 Alain Hovnanian 10,11, John A. McGrath, Jemima E. Mellerio, Johann W. Bauer³, and Andrew P. South' 4,9 16 Clin Cancer Res March 7 2019 DOI:10.1158/1078-0432.CCR-18-2661. PMID: 30846478 0 ONCONOVA THERAPEUTICS#17Polo-like kinase-1 identified as a therapeutic target in RDEB CSCC 17 Oncogene. 2011 30(46):4666-77. PMID: 21602893 PMCID: PMC3219832 Isolate primary cells from cSCC Gene expression analysis in vitro Tumour cells scored through genetic alteration, either SNP mapping or cytogenetics Integrative analysis comparing clinical expression data siRNA screen In vitro target validation In vivo validation 0 ONCONOVA THERAPEUTICS#18Polo-like kinase-1 identified as a therapeutic target in RDEB CSCC Psoriasis skin = benign SCC = malignant 18 Oncogene. 2011 30(46):4666-77. PMID: 21602893 PMCID: PMC3219832 0 ONCONOVA THERAPEUTICS#19Polo-like kinase-1 identified as a therapeutic target in RDEB CSCC Psoriasis vs NLS Fold Change 19 Oncogene. 2011 30(46):4666-77. PMID: 21602893 PMCID: PMC3219832 Fold change comparison SCC vs normal skin with psoriasis lesional vs non-lesional skin 0 10 T 10 SCC vs NS Fold Change • SCC / Psors in Common • SCC specific 100 0 ONCONOVA THERAPEUTICS#20Polo-like kinase-1 identified as a therapeutic target in RDEB CSCC 60 40 20 -20 -40 -60 -80 -100 0 T = B HO F HO HE 20 20 Oncogene. 2011 30(46):4666-77. PMID: 21602893 PMCID: PMC3219832 = www HO - HE HE Cell Death Control siRNA H H A F CH = HE HH B AI E HB H PLK1 siRNA L HO H F H = ☐ E == HO HE 0 ONCONOVA THERAPEUTICS#2121 Rigosertib identified as lead PLK1 inhibitor in RDEB CSCC Inhibitor Pharma BI 2536 Boehringer Ingelheim, Ingelheim, Germany Supplier Selleck Chemicals, Houston, TX PLK 1 IC 50 Clinical trial Delivery IC50 0.83nM Phase II complete IV GW843682X GSK461364 GlaxoSmithKline, Middlesex, UK GlaxoSmithKline, Middlesex, UK Tocris Biosciences, Bristol, UK Selleck Chemicals, Houston, TX IC50 2.2nM IC50 2.2nM EC50 <100nm in cell lines Phase I complete IV TKM-080301 Tekmira Pharmaceuticals Corporation Phase I recruiting IV NMS-1286937 Nerviano Medical Sciences, Milano, Italy BI 6727 Boehringer Ingelheim, Ingelheim, Germany Active Biocehmical Co., Ltd. or Jihpharma Shanghai Sun-shine Chemical Technology Co., Ltd. Phase I recruiting Oral Phase II recruiting IV References Steegmaier et al. Current Biology.2007 17(4):316-322 Lansing et al (2007) Mol. Cancer Ther. 6 450. Sato Y et al. Bioorg Med Chem Lett. 2009 19(16):4673-8. Beria et al., Presented at EORTC-NCI-AACR 2008; Geneva, Switzerland. Rudolph et al., Presented at EORTC-NCI-AACR Geneva, Switzerland, 2008. CYC-800 Cyclacel Ltd, Dundee, UK TAK-960 ON-01910 Millennium Onconova Therapeutic, Newtown, PA EC50 low nM range Oral AACR 2010 abstract Phamaceuticals, C. Selleck Chemicals, Houston, TX IC50 9nM EC50 50-250nM Phase I Tecruiting Phase II recruiting Oral IP Gumireddy K et al. Cancer Cell. 2005 7(3):275-86. OL Kyoto, Japan 5-(5,6-Dimoxy-1H- benzi-1-yl)-3-[[4- (methylsulfonyl)phenyl ]methoxy]-2-T. Houston, TX OTAVA Ltd, Toronto, Canada F050 110 IC50 6.9nM ZK-Thiazolidinone (TAL) Bayer Schering Pharma AG N/A IC50 19nM Cell lines EC50 0.2-1.3uM DAP-81 Rockefeller University, New York IC50 0.9nM Clin Cancer Res March 7 2019 DOI:10.1158/1078-0432.CCR-18-2661. PMID: 30846478 2003 63:6942-7 Santamaria et al (2007) Mol Biol Cell 18, 4024-4036 Peters et al., Nat Chem Biol 2006;2:618-626. ONCONOVA THERAPEUTICS#22Rigosertib identified as lead PLK1 inhibitor in RDEB CSCC Rigosertib Concentration 48 hrs exposure DMSO 0.01uM 0.1uM 1uM 10uM 100uM Primary Foreskin Keratinocytes Primary Breast Keratinocytes Primary RDEB 85 Keratinocytes Primary RDEB 93 Keratinocytes RDEB 2 SCC Keratinocytes RDEB 3 SCC Keratinocytes RDEB 4 SCC Keratinocytes 22 Clin Cancer Res March 7 2019 DOI:10.1158/1078-0432.CCR-18-2661. PMID: 30846478 EID 0 ONCONOVA THERAPEUTICS#23Rigosertib identified as lead PLK1 inhibitor in RDEB CSCC Percentage viability B 200- 150- 100- 50- RDEB SCC (n = 10) (n=10) Normal keratinocytes (n=4) ✰ SCCRDEB2 SCCRDEB3 SCCRDEB4 0- -4 -3 -2 log ON-01910, mmol/L 23 Clin Cancer Res March 7 2019 DOI:10.1158/1078-0432.CCR-18-2661. PMID: 30846478 Percentage viability 100- 50- -5-4-3 -2 log ON-01910, mmol/L 0 ONCONOVA THERAPEUTICS#24Rigosertib identified as lead PLK1 inhibitor in RDEB CSCC C A 1600 1400 1200 1000 800 600 Tumor volume (mm³) 400 ** 200 0 Rigosertib Vehicle Tumor 1 * *** *** *** *** *** *** *** *** *** ** 7 8 9 10 11 12 13 14 15 Day Tumor 2 Vehicle Rigosertib Tumor weight (gr) B 2 1.8 1.6 1.41 1.2 1- ** 0.8 0.6 0.4- 0.2 0 Vehicle Rigosertib Tumor 3 Tumor 4 Tumor 5 Tumor 6 Tumor 7 Tumor 8 24 Clin Cancer Res March 7 2019 DOI:10.1158/1078-0432.CCR-18-2661. PMID: 30846478 0 ONCONOVA THERAPEUTICS#25Rigosertib: IV or oral delivery Published OnlineFirst February 3, 2014; DOI: 10.1158/1078-0432.CCR-13-2506 Clinical Cancer Research Cancer Therapy: Clinical Phase I Study of Oral Rigosertib (ON 01910.Na), a Dual Inhibitor of the PI3K and Plk1 Pathways, in Adult Patients with Advanced Solid Malignancies Daniel W. Bowles', Jennifer R. Diamond', Elaine T. Lam', Colin D. Weekes', David P. Astling', Ryan T. Anderson, Stephen Leong, Lia Gore, Marileila Varella-Garcia, Brian W. Vogler1, Stephen B. Keysar¹, Elizabeth Freas, Dara L. Aisner, Chen Ren³, Aik-Chook Tan¹, Francois Wilhelm³, Manoj Maniar³, S. Gail Eckhardt, Wells A. Messersmith', and Antonio Jimeno¹ 25 Clin Cancer Res Feb 3 2014 DOI:10.1158/1078-0432.CCR-13-2506 MID: 0 ONCONOVA THERAPEUTICS#26Rigosertib: low toxicity profile 26 Clin Cancer Res Feb 3 2014 DOI:10.1158/1078-0432.CCR-13-2506 MID: 0 ONCONOVA THERAPEUTICS#27ONCONOVA THERAPEUTICS NCT03786237 Austrian Rigosertib Trial Johann Bauer, MD#2828 Patient AT-01_01 April 21-April 22 left hand right elbow V1 V13 V25 V41 V52 December 22 Presented at the annual meeting of the Austrian Society of Dermatology and Venerology, virtual 2021 LANDSKRANKENHAUS SALZBURG UNIVERSITÄTSKLINIKUM DER PARACELSUS MEDIZINISCHEN PRIVATUNIVERSITAT eb Haus Austria. 1 ONCONOVA THERAPEUTICS#2929 ri. elbow: August 2021, 8 cycles_V15; granulation tissue LANDESKRANKENHAUS SALZBURG UNIVERSITÄTSKLINIKUM DER PARACELSUS MEDIZINISCHEN PRIVATUNIVERSITAT & eb Haus Austria. 0 ONCONOVA THERAPEUTICS#3030 ri. hand Recurrence 02/23: 8/10 No systemic metastases (04/23) LANDESKRANKENHAUS SALZBURG UNIVERSITÄTSKLINIKUM DER PARACELSUS MEDIZINISCHEN PRIVATUNIVERSITAT & eb Haus Austria. 0 ONCONOVA THERAPEUTICS#3131 Patient AT-01_02 TU initial (3/23) TU follow up (4/23): 3 cycles USC RE Daum UNIKLINIKUM Patient LANDESKRANKENHAUS SALZBURG UNIVERSITÄTSKLINIKUM DER PARACELSUS MEDIZINISCHEN PRIVATUNIVERSITÄT eb Haus Austria ง ONCONOVA THERAPEUTICS#32ONCONOVA THERAPEUTICS NCT04177498 USA Rigosertib Trial Neda Nikbakht, MD, PhD, FAAD Lauren Banner, Linda Hosler, Alexa Cohen#33NCT04177498: "A Pilot, Open Study to Assess Efficacy and Safety of Rigosertib in Patients With Recessive Dystrophic Epidermolysis Bullosa Associated Locally Advanced/Metastatic Squamous Cell Carcinoma" USA site: Thomas Jefferson University, Philadelphia, PA Status: Active and Enrolling, oral arm is recruiting 0 ONCONOVA THERAPEUTICS#3434 USA Trial: NCT04177498 Study Population: RDEB patients with advanced SCC who have failed prior standard of care. Primary Objectives: To estimate the anti-tumor activity of oral or IV rigosertib by determining the overall response rate, defined as the proportion of patients who achieve either a complete response or a partial response by RECIST v1.1 criteria To evaluate the safety and tolerability of oral rigosertib administered daily three weeks on, one week off for 12 cycles or IV rigosertib administered as continuous 72h IV infusions once every two weeks for 8 cycles and then once every 4 weeks thereafter 0 ONCONOVA THERAPEUTICS#3535 Jefferson Patient HPI: A 32-year-old woman with RDEB and history of several cutaneous SCCs with nodal involvement who failed multiple treatment modalities presented to Jefferson in 2022. Medical history: Esophageal Strictures Malnutrition Loss of teeth Anemia Prior treatments: Excision: left hand, scalp SCC (2015) Mohs: right and left arm SCC (2015), left wrist SCC (2017) Cetuximab (2016) Pembrolizumab (11/2018-1/2019, 4 cycles) Excisions: right hip, thigh, arm, ankle, foot, left hand, wrist, thigh, knee (2020-2022) Medications: • Iron infusions, PRN Gabapentin, PRN Ibuprofen, PRN Acetaminophen with codeine, PRN Hydroxyzine, PRN Banner, et al. poster 613, ISID 2023 0 ONCONOVA THERAPEUTICS#3636 Nodal Involvement at Enrollment: Before Pembrolizumab: (10, 2018) Left axillary lymph node core needle biopsy demonstrated squamous cell carcinoma Pembrolizumab (11/2018-1/2019, 4 cycles) discontinued due to autoimmune sequelae After Pembrolizumab: (4, 2019) Left axillary lymph node dissection suggested metastatic squamous cell carcinoma At Enrollment: (9, 2022) Multiple enlarged lymph nodes on imaging, none were eligible as target lesions per RECIST v1.1 Banner, et al. poster 613, ISID 2023 ง ONCONOVA THERAPEUTICS#3737 Skin Involvement at Enrollment: S3HON Banner, et al. poster 613, ISID 2023 0 ONCONOVA THERAPEUTICS#3838 Skin Involvement at Enrollment: Left elbow: Squamous Cell Carcinoma Banner, et al. poster 613, ISID 2023 0 ONCONOVA THERAPEUTICS#3939 Oral Rigosertib produces levels in blood comparable to non-RDEB patients Dosing: 560 mg BID, 3 weeks on, one week off Concentration (ng/mL) 20000 18000 4 16000 14000 12000 10000 8000 6000 4000 2000 0 0 1 2 3 4 LO Time (h) -Cycle 1 --Cycle 2 -- Cycle 3 -*-Cycle 4 0 ONCONOVA THERAPEUTICS#40Patient achieved complete clinical remission with oral Rigosertib www 109 Cycles 6-8 0 mm² Banner, et al. poster 613, ISID 2023 0 ONCONOVA THERAPEUTICS Baseline Cycle 1 1045 mm² 770 mm² Cycle 2 453 mm² Cycle 3 337.5 mm² Cycle 4 248 mm²* Cycle 5 0 mm² 40 40 ALWAY#4141 Patient achieved complete histological remission with oral Rigosertib Baseline 200 m Cycle 4 Cycle 6 SCC, invasive SCC, resolving superficial Scar Banner, et al. poster 613, ISID 2023 ONCONOVA THERAPEUTICS#4242 Challenges: Urinary symptoms Patient experienced urinary urgency and frequency often Trial of Oxybutynin (not helpful), Mirabegron (slightly more helpful) Patient experienced grade 3 hematuria leading to dose reduction Sodium bicarbonate, Phenazopyridine, hydration Banner, et al. poster 613, ISID 2023 0 ONCONOVA THERAPEUTICS#4343 Challenges: Difficulty with oral intake Protocol was most recently amended to allow modification of oral intake for patients with esophageal strictures or G-tubes Dissolving capsules in water before intake Allowing administration of dissolved medication through G-tube Venous access issues Prioritizing and balancing studies requiring IV access Medical insurance coverage ⚫ Patients traveling out of state (Michigan and New York) Lauren Banner Banner, et al. poster 613, ISID 2023 0 ONCONOVA THERAPEUTICS#44Second patient from New York was enrolled last week at Jefferson 44 0 ONCONOVA THERAPEUTICS#45ONCONOVA THERAPEUTICS Steven Fruchtman, M.D President and CEO Onconova Therapeutics#4647 Rigosertib's Current Status and Potential Next Steps Including but not limited to: • Continue enrollment for the Phase 1/2a trial of oral rigosertib + nivolumab in KRAS-mutated, CPI resistant, non-small cell lung cancer • Identification of additional sites and patients for the RDEB-associated SCC trial Initiation of investigator-sponsored study of oral rigosertib + pembrolizumab in patients with CPI resistant melanoma Ongoing preclinical studies in various RASopathies • Preclinical combinations studies with sotorasib and other combinations of interest 0 ONCONOVA THERAPEUTICS#47ONCONOVA THERAPEUTICS Thank You! [email protected]