Investor Presentation January 2020 Forward-Looking Statements This - PowerPoint PPT Presentation

Science-Based Innovation-Focused ADC Company Investor Presentation January 2020

Forward-Looking Statements This presentation, in addition to historical information, contains certain forward- looking statements made pursuant to the Private Securities Litigation Reform Act of 1995. Such statements may involve significant risks and uncertainties, and actual results could differ materially from those expressed or implied herein. Factors that could cause such differences include, but are not limited to, new product development (including clinical trials outcome and regulatory requirements /actions); competitive risks to marketed products; forecasts of future operating results; availability of required financing and other sources of funds on acceptable terms, if at all; as well as those discussed in the Company's filings with the Securities and Exchange Commission. 2

T H E I M M U N O M E D I C S S T O R Y Company Transformed in Less Than Three Years Unique ADC platform May 2017 Validated target Multiple Phase 3 studies Large opportunities Global partnerships • Commercial • Clinical • Manufacturing Unencumbered asset Long IP protection From: A science focused company To: A fully-integrated biopharmaceutical company 3

A Powerful Differentiated ADC Platform: Three Key Advantages 1. Payload – Validated & Well 2. Novel Linker Tolerated • Hydrolyzable linker for payload • ADC platform uses SN-38 as release payload of choice • Allows for intra- and extra-cellular • SN-38 kills cancer cells by (bystander effect) killing of tumor damaging DNA cells 3. Antibody – Highly Tumor Specific • hRS7 in sacituzumab govitecan targets Trop-2 in multiple solid tumor indications • Other pipeline assets: labetuzumab govitecan targets CEACAM5, IMMU-140 targets HLA-DR 4

Multiple Sacituzumab Govitecan Programs to Address Unmet Needs in Trop-2-Expressing Cancers Indication Designation Phase 1 Phase 2 Phase 3 Approval Partner mTNBC (3L+) Under FDA Review mTNBC (3L) ASCENT Top-line Readout Expected Mid-2020 HR+/HER2‒ mBC TROPiCS-02 mTNBC (1L) (+ Tecentriq) MORPHEUS mTNBC / mUC / Ovarian (+ Rubraca) SEASTAR mTNBC / mUC / mNSCLC (+ Imfinzi) HER2 ‒ BC (Post-neoadjuvant) SASCIA Urothelial (3L) TROPHY-U-01 Cohort 1 Enrollment Completed Urothelial (3L) (Pending FDA Discussion) mNSCLC / H&N / Endometrial (Trop-2-enriched) TROPiCS-03 5

Overall TNBC Opportunity with Sacituzumab Govitecan Poised to Become the Foundational Therapy Stage 1, 2 and 3 (resectable) Neo/Adjuvant (24- 26k Pts) Phase 3 SASCIA Stage 3 locally advanced (unresectable), Stage 4 metastatic 1 st Line (10-11k Pts) Phase 1b/2 MORPHEUS Phase 1/2 2 nd Line (9-10k Pts) Phase 1/2 SEASTAR 3rd Line+ Phase 3 ASCENT (8-9k Pts) 6

C O M M E R C I A L I Z A T I O N P L A N Three Goals at Launch 1. Establish sacituzumab govitecan as standard of care for 3 rd -line mTNBC • Drive rapid awareness & adoption through product education 2. Optimize positive early clinical experience Goals • Minimize barriers, set clear expectations, educate on adverse event management 3. Become a recognized leader in TNBC • Build strong scientific and development partnerships 7

C O M M E R C I A L I Z A T I O N P L A N Executing Strong Commercial Strategy – U.S. Launch Ready • Sales team in place and transitioning from Balversa Commercial co-promotion with Janssen 1 Infrastructure • Marketing, market access and commercial operations teams in place • 30-60-90 day territory call routing plans in place 2 Initial Targets • Expanded marketing mix will drive awareness at launch • High unmet need 3 Reimbursement • Targeted patient population • Highly differentiated benefit:risk profile • Product will ship at approval 4 Manufacturing • End-to-end supply chain in place • Additional supply-chain sourcing underway 8

S A C I T U Z U M A B G O V I T E C A N F O R m T N B C – O V E R V I E W Highly Differentiated Therapy for mTNBC Treatment Line • mTNBC patients with at least 2 prior treatments in the metastatic setting The Unmet Need • Low response rates, short response duration and significant side effects with currently available therapies • Patients with pre-existing peripheral neuropathy or cardiac impairment may only have supportive care options Market Size • U.S. ~8k patients • EU5, Japan ~14k patients Status • Accelerated approval pending • PDUFA date: June 2, 2020 9

Low Response Rates in Pre-treated mTNBC* Drug Phase N Population ORR (%) PFS (mos) 1st line treatment 1 st line Carboplatin 1 3 188 31 3.1 1 st line Docetaxol 1 3 188 36 4.5 1 st line (80.2%) Cis/Carboplatin 2 2 86 25.6 2.9 >1st line treatment Ixabepilone 3 2 60 Resistant to A, C & T or T only 6 - 17 1.6 - 2.7 Capecitabine 3 3 208 Prior or resistant to A & T 15 1.7 Eribulin 4 3 199 > 1 prior chemo 11 2.8 ESMO 2019 3 rd line mBC (~30% TNBC) Eisai 5 2 443 ~2.5 - 3.1 (cap, gem, erib) 2 nd line (60%), 3 rd line (40%) KEYNOTE-119 6 3 622 9.6 (K), 10.6 (chemo) 2.1 (K), 3.3 (chemo) * Includes breast cancer drugs with data from Phase 2/3’s with minimum mTNBC sample size > 60; ORR and PFS data Source of data: 1) Tutt A, SABCS 2014; 2) Isakoff SJ, J Clin Oncol 2015; 3) Perez EA, Breast Can Res Treat 2010; 4) Pivot X, Ann Oncol 2016 5) Kazmi S, ESMO 2019 Abstract 366P, 6) Cortes J, KEYNOTE-119, ESMO 2019 10

E V I D E N C E O F E F F E C T I V E N E S S Sacituzumab Govitecan Achieved Impressive ORR and PFS Compared to SoC in Late-Line mTNBC * ORR PFS (%) (months) 33 5.5 (N=108) (N=108) 18 2.8 2.7 15 11 1.7 Capecitabine Eribulin in Capecitabine Taxane, Cap, Sacituzumab Eribulin in Taxane, Cap, Sacituzumab in 2 nd line 2 2 nd line 1 in 2 nd line 2 2 nd line 1 Gem or Vin in Govitecan in Gem or Vin in Govitecan in 2 nd line 3 ≥3 rd line 4 2 nd line 3 ≥3 rd line 4 * Information is based on comparative results from independent studies 11 Source of data: 1) Pivot X, Ann Oncol 2016; 2) Perez EA, Breast Can Res Treat 2010; 3) Brufsky A, Breast Can Res Treat. 2012; 4) Bardia A, NEJM 2019

E V I D E N C E O F E F F E C T I V E N E S S Duration of Treatment Underscores Sacituzumab Govitecan Clinical Activity Median Last Prior Therapy 2.5 months Sacituzumab Govitecan 5.1 months Source of data: Bardia A, et al. Sacituzumab Govitecan-hziy in Refractory Metastatic Triple-Negative Breast Cancer. N Engl J Med. 2019; 380:741-51 12

Confirmatory ASCENT Study of Sacituzumab Govitecan Completed Target Enrollment Indication Twin Arm Study Endpoint mTNBC Sacituzumab govitecan Continue treatment 10 mg/kg IV ≥2 prior treatments until progression day 1 & 8, every 21 days OR N = 488  1 therapy for advanced Primary Endpoint disease who also • PFS Traditional chemotherapy progressed within 12 treatment of Secondary Endpoint months of (neo)adjuvant physicians’ choice* • OS therapy * Eribulin, gemcitabine, capecitabine & vinorelbine ASCENT Phase 3 Readout: Expected in mid-2020 National Institutes of Health. https://clinicaltrials.gov/ct2/show/NCT02574455 13

Metastatic Urothelial Cancer – Targeting our 2 nd High Unmet S A C I T U Z U M A B G O V I T E C A N F O R U R O T H E L I A L C A N C E R - O V E R V I E W Need Indication The Unmet Need • Current therapies for metastatic disease post chemotherapy and immune checkpoint inhibitors offer low response rate, short response duration and high toxicity Market Size • 3 rd line mUC – U.S. ~8k patients • 3 rd line mUC – EU5, Japan ~10k patients Status • May obtain accelerated approval based on results of Ph 2 TROPHY-U-01 trial 14

E V I D E N C E O F E F F E C T I V E N E S S Sacituzumab Govitecan Achieved Strong ORR and PFS Compared to SoC in Phase 1/2 Single-Arm Basket Study* ORR PFS (%) (months) 7.3 31 (N=45) (N=45) 3.0 2.8 14 2.8 8.9 8.6 Vinflunine Docetaxel Docetaxel Sacituzumab Vinflunine Docetaxel Docetaxel Sacituzumab in 2 nd line 1 in 2 nd line in 2 nd line in 2 nd line 1 in 2 nd line in 2 nd line Govitecan in Govitecan in ≥ 3 rd line 4 ≥ 3 rd line 4 Phase 2 2 Phase 3 3 Phase 2 2 Phase 3 3 * Information is based on comparative results from independent studies 15 Source of data: 1) Bellmunt J, JCO 2009; 2) Petrylak D, JCO 2016; 3) Petrylak D, Lancet 2017; 4) Tagawa S, ASCO-GU 2019

Pivotal TROPHY-U-01 Study of Sacituzumab Govitecan Designed to Support Accelerated Approval Indication Single-Arm Study Endpoint mUC Continue treatment Cohort 1: Post platinum- until progression and CPI-based therapies Sacituzumab govitecan (N= 100) 10 mg/kg IV Primary Endpoint OR day 1 & 8, every 21 days • ORR (BICR) Cohort 2: 2 nd line post CPI Secondary Endpoint for cisplatin-ineligible • DoR, PFS & OS patients (N = 40) • First patient dosed in August 2018 in U.S. • Interim results presented at ESMO 2019 • Cohort 1 enrollment reached in October 2019 16 National Institutes of Health. https://clinicaltrials.gov/ct2/show/NCT03547973