Highlights of ADC Therapeutics Presentations ASH 2020 Virtual Meeting

Mehdi Hamadani Division of Hematology and Oncology, Medical College of Wisconsin, Milwaukee, WI, USA

December 7, 2020 Lonca and Cami in Lymphoma

Loncastuximab tesirine (Lonca) • A substantial proportion (~40%) of patients with DLBCL are refractory to immunochemotherapy or relapse1–3 CD19-directed PBD-conjugated ADC o Patients with high-risk R/R DLBCL have particularly • poor prognosis2,4 Single-agent Lonca: Phase 2 trial in R/R DLBCL • Many patients are not suitable for salvage therapy with • Combination therapy trials ongoing: HSCT and current treatments have significant toxicity3-6 o Lonca + ibrutinib: Phase 1/2 trial in R/R DLBCL and R/R MCL • There is unmet need for easily administered, effective, o Lonca + rituximab vs R-GemOx: Phase 3 trial in R/R DLBCL and less toxic salvage treatments3-6

Camidanlumab tesirine (Cami) • Therapeutic options are also limited for patients with CD25-directed PBD-conjugated ADC R/R cHL who do not respond to treatments such as brentuximab vedotin and checkpoint inhibitors, or who relapse after initially responding7,8 • Single-agent Cami: Phase 2 trial in cHL

1. Sehn and Gascoyne. Blood 2015;125:22–32; 2. Feugier et al. J Clin Onc 2005;23:4117–26; 3. Gisselbrecht and Van Den Neste. Br J Haematol 2018;182:633–43; 4. Costa et al. Am J Hematol 2017;92:161–70; 5. Crump et al. Blood 2017;130:1800–8; 6. Levin and Shah. Am J Hematol 2019;94: S18–23; 7. Mehta-Shah et al. Blood 2018;131:1698–703; 8. Glimelius et al. J Intern Med 2017;281:247–60. ADC, antibody-drug conjugate; B-NHL, B-cell non-Hodgkin lymphoma; cHL classical Hodgkin lymphoma; DLBCL, diffuse large B-cell lymphoma; mAb, monoclonal antibody; MCL, mantle cell lymphoma; PBD, pyrrolobenzodiazepine; R-GemOx, rituximab/gemcitabine/oxaliplatin; R/R, relapsed or refractory. Efficacy and Safety of Loncastuximab Tesirine (ADCT-402) in Relapsed/Refractory Diffuse Large B-Cell Lymphoma Paolo F. Caimi, et al

Poster slides, 62nd ASH Annual Meeting and Exposition Virtual Meeting, December 5–8, 2020 Introduction and Methods

Lonca had substantial antitumor activity and an acceptable safety profile in this single-arm open-label Phase 2 study (NCT03589469) in adult patients with R/R DLBCL, who had failed ≥2 established therapies1

30-minute infusion of Lonca Q3W for up to 1 year Q12W for up to 3 years

150 µg/kg 75 µg/kg Follow-up

First 2 cycles After 2 cycles

Here, we present updated results including analysis of response in subgroups with high risk for poor prognosis Pre-specified analyses of ORR and DoR by demographic and clinical characteristics were performed

1. Carlo-Stella et al. EHA Congress 2020. Abstract S233. DLBCL, diffuse large B-cell lymphoma; DoR, duration of response; Lonca, loncastuximab tesirine; ORR, overall response rate; PBD, pyrrolobenzodiazepine; Q3W, every 3 weeks; Q12W, every 12 weeks; R/R, relapsed/refractory.

4 Activity of Lonca in High-risk R/R DLBCL

Lonca ORR: 48.3% (95% CI: 39.9. 56.7); Lonca CRR: 24.8% (95% CI: 18.0, 32.7)

Encouraging ORRs were seen in high-risk subgroups

Subgroup Patients (n/N) ORRORR ORR (95% CI) Subgroup Patients (n/N) ORR ORR (95% CI)

All 70/145 48.3 (39.9, 56.7) All 70/145 48.3 (39.9, 56.7) Age First-line response* <65 years 32/65 49.2 (36.6, 61.9) Relapse 53/99 53.5 (43.2, 63.6) ≥65 years 38/80 47.5 (36.2, 59.0) Refractory† 11/29 37.9 (20.7, 57.7) Double/triple hit Last-line response* No 65/130 50.0 (41.1, 58.9) Relapse 29/43 67.4 (51.5, 80.9) Yes 5/15 33.3 (11.8, 61.6) Refractory† 31/84 36.9 (26.6, 48.1) Transformed disease Response to any prior line* Transformed 13/29 44.8 (26.4, 64.3) Relapse 60/115 52.2 (42.7, 61.6) De novo 57/116 49.1 (39.7, 58.6) Refractory† 9/25 36.0 (18.0, 57.5) Cell-of-origin Prior stem cell transplant GCB 26/48 54.2 (39.2, 68.6) Yes 14/24 58.3 (36.6, 77.9) ABC 11/23 47.8 (26.8, 69.4) No 56/121 46.3 (37.2, 55.6) Double/triple expressor Prior CAR-T therapy No 60/125 48.0 (39.0, 57.1) Yes 6/13 46.2 (19.2, 74.9) Yes 10/20 50.0 (27.2, 72.8) No 64/132 48.5 (39.7, 57.3) WHO classification Prior systemic therapies DLBCL NOS 64/127 50.4 (41.4, 59.4) 2 prior lines 30/63 47.6 (34.9, 60.6) PMBCL 1/7 14.3 (0.4, 57.9) 3 prior lines 17/35 48.6 (31.4, 66.0) HGBCL 5/11 45.5 (16.7, 76.6) >3 prior lines 23/47 48.9 (34.1, 63.9)

0.0 0.2 0.4 0.6 0.8 1.0 0.0 0.2 0.4 0.6 0.8 1.0

ORR was assessed by independent reviewer. *Prior systemic therapies. †Refractory disease defined as no response to therapy. Data cut-off: 06 August, 2020. ABC, activated B-cell-like; CAR-T, chimeric antigen receptor T-cell; CI, confidence interval; CRR, complete response rate; DLBCL, diffuse large B-cell lymphoma; GCB, germinal center B-cell-like; HGBCL, high grade B-cell lymphoma; NOS, not otherwise specified; ORR, overall response rate; PMBCL, primary mediastinal B-cell lymphoma; WHO, World Health Organization.

5 Duration of Response

Number of Events: 1.0 CR: 6 PR: 16* 0.9 CR+PR: 22 mDoR for the 70 0.8 responders: + Censored 0.7 12.58 months 0.6 0.5 (95% CI: 6.87, - )

Probability 0.4 0.3 0.2 0.1 0.0 At risk: CR 36 35 31 30 26 23 21 19 18 17 13 9 6 3 2 2 2 2 1 1 0 mDoR for patients PR 34 28 12 9 7 6 4 3 2 2 2 0 0 0 0 0 0 0 0 0 0 CR+PR 70 63 43 39 33 29 25 22 20 19 13 9 6 3 2 2 2 2 1 1 0 with a CR: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 13.37 months Time (months) (95% CI: 12.58, - ) Response: CR PR CR+PR

mDoR was comparable to the whole study population in subgroups at high risk of poor prognosis Patients continue to be followed for DoR DoR was defined as the time from earliest date of first response until the first date of either disease progression or death due to any cause. *mDoR for patients with a PR: 5.68 months (95% CI: 1.64, 6.87). Data cut-off: 06 August, 2020 CI, confidence interval; CR complete response; mDOR, median duration of response; PR, partial response. PFS, OS, and Subsequent Treatment

Median PFS: 5.09 months (95% CI: 2.89, 8.31) Median OS: 9.53 months (95% CI: 6.93, 11.24)

Number of Events: 72 Number of Events: 88

1.0 + Censored 1.0 + Censored 0.9 0.9 0.8 0.8 0.7 0.7 0.6 0.6 0.5 0.5 Probability

0.4 Probability 0.4 0.3 0.3 0.2 0.2 0.1 0.1 0.0 0.0 At risk 145 124 85 57 47 37 34 29 27 24 20 17 11 11 8 4 3 3 3 2 2 0 At risk 145136 127116 111 98 89 78 72 67 62 52 38 31 27 21 15 12 10 6 5 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 Time (months) Time (months)

• 15 patients received CD19-directed CAR-T therapy with an investigator-assessed ORR of 46.7% (6 CR; 1 PR) Subsequent Treatment • 9 patients proceeded to SCT as consolidation after Lonca response

Data cut-off: 06 August, 2020. CAR-T, chimeric antigen receptor T-cell; CI, confidence interval; CR, complete response; Lonca, loncastuximab tesirine; ORR, overall response rate; OS, overall survival; PFS, progression-free survival; PR, partial response; SCT, stem cell transplant. Safety

TEAEs in ≥20% of the all-treated population Most common (≥10%) grade ≥3 TEAEs were: Patients n (%) • Neutropenia (38 patients; 26.2%) <65 years ≥65 Total • Thrombocytopenia (26 patients; 17.9%) Preferred term (N=65) (N=80) (N=145) • GGT increased (25 patients; 17.2%) Patients with any TEAE 65 (100) 78 (97.5) 143 (98.6) • Anemia (15 patients; 10.3%) GGT increased 33 (50.8) 27 (33.8) 60 (41.4) Neutropenia 34 (52.3) 24 (30.0) 58 (40.0) Treatment-related TEAEs leading to treatment Thrombocytopenia 28 (43.1) 20 (25.0) 48 (33.1) discontinuation occurred in 26 (17.9%) patients, Fatigue 21 (32.3) 19 (23.8) 40 (27.6) most commonly (≥2%): Anemia 23 (35.4) 15 (18.8) 38 (26.2) • GGT increased (16 patients; 11.0%) Nausea 17 (26.2) 17 (21.3) 34 (23.4) • Peripheral edema (4 patients; 2.8%) Cough 19 (29.2) 13 (16.3) 32 (22.1) • Localized edema (3 patients; 2.1%) Alkaline phosphatase 18 (27.7) 11 (13.8) 29 (20.0) increased No increase in toxicity was seen in patients aged ≥65 years Peripheral edema 11 (16.9) 18 (22.5) 29 (20.0) compared with younger patients

TEAEs were reported for the all-treated population. Data cut-off: 06 August, 2020. GGT, gamma-glutamyltransferase; TEAE, treatment-emergent adverse event.

8 Conclusions

Lonca had substantial single-agent antitumor activity in patients with R/R DLBCL; ORR was 48.3% and CRR was 24.8%

Durable responses were reported (mDoR 12.58 months), particularly in patients achieving a CR (mDoR 13.37 months)

Encouraging and durable responses were observed in high-risk patient groups, including double- or triple-hit, transformed or refractory DLBCL, and notably in those who had progression after prior CAR-T therapy

No new safety concerns were identified and no increase in toxicity was observed in patients aged ≥65 years

CAR-T, chimeric antigen receptor T-cell; CR, complete response; CRR, complete response rate; DLBCL, diffuse large B-cell lymphoma; Lonca, loncastuximab tesirine; mDoR, median duration of response; ORR, overall response rate; R/R, relapsed or refractory.

9 Interim Results of Loncastuximab Tesirine Combined With Ibrutinib in Diffuse Large B-Cell Lymphoma or Mantle Cell Lymphoma (LOTIS-3)

Julien Depaus, et al

Poster slides, 62nd ASH Annual Meeting and Exposition Virtual Meeting, December 5–8, 2020 Objectives and Study Design for Phase 1

Primary objective for Phase 1: Secondary objectives for Phase 1: • Characterize safety/tolerability and identify the • Evaluate antitumor effect RP2D and schedule for use in Phase 2 • Characterize pharmacokinetics • Evaluate immunogenicity

SCREENING PERIOD TREATMENT PERIOD

Lonca IV Q4W PHASE 1 Lonca (escalating doses) Non-GCB DLBCL ×2 additional doses ENDOF TREATMENT IV Q3W for Cycles 1 and 2 PR/SD GCB DLBCL ASSESSMENT MCL Continue ibrutinib po daily Ibrutinib po daily CR Continue ibrutinib po daily PHASE 2 Non-GCB DLBCL Lonca (60 µg/kg) Lonca (60 µg/kg) IV Q4W for GCB DLBCL IV Q3W for Cycles 1 and 2 CR/PR/SD Cycles 5, 6, 9, and 10 MCL Ibrutinib po daily Continue ibrutinib po daily

Week 14 Up to 1 year

CR, complete response; DLBCL, diffuse large B-cell lymphoma; GCB, germinal center B-cell; IV, intravenous; Lonca, loncastuximab tesirine; MCL, mantle cell lymphoma; po, taken orally; PR, partial response; RP2D, recommended Phase 2 dose; SD, stable disease; Q3W, every 3 weeks; Q4W, every 4 weeks. Patient Characteristics Median Median Lonca ibrutinib cycles: cycles: As of August 20, 2020, 37 patients had received Lonca 60 µg/kg plus ibrutinib 560 mg 2 4 (range 1–4) (range 1–14)

DLBCL MCL All patients DLBCL MCL All patients Characteristic Characteristic (n=30) (n=7) (n=37) (n=30) (n=7) (n=37) Sex, n (%) Number of prior systemic therapiesb Male 21 (70.0) 6 (85.7) 27 (73.0) Median (range) 2 (1–6) 2 (1–4) 2 (1–6) Age, years, median (range) 72 (40–91) 69 (54–89) 72 (40–91) First-line prior therapy response, n (%)c ECOG status, n (%) 20 (66.7) 4 (57.1) 24 (64.9) Relapsed 0 16 (53.3) 4 (57.1) 20 (54.1) 7 (23.3) 1 (14.3) 8 (21.6) Refractory 1 11 (36.7) 3 (42.9) 14 (37.8) 3 (10.0) 2 (28.6) 5 (13.5) Other 2 3 (10.0) 0 3 (8.1) Last-line prior therapy response, n NHL subtype, n (%) (%)c,d 13 (43.3) 4 (57.1) 17 (45.9) Non-GCB DLBCL 24 (80.0) - 24 (64.9) Relapsed 17 (56.7) 1 (14.3) 18 (48.6) GCB DLBCL 6 (20.0) - 6 (16.2) Refractory 0 2 (28.6) 2 (5.4) MCL - 7 (100) 7 (18.9) Other Disease stagea, n (%) Prior SCT, n (%) Stage II 3 (10.0) 0 3 (8.1) Autologous 2 (6.7) 1 (14.3) 3 (8.1) Stage III 5 (16.7) 1 (14.3) 6 (16.2) Allogeneic 0 1 (14.3) 1 (2.7) Stage IV 22 (73.3) 6 (85.7) 28 (75.7)

Data cut: August 20, 2020. aAnn Arbor Criteria; bPrior SCT is included. For patients who received an autologous transplant, the mobilization regimen was considered a line of therapy if it was chemotherapy based and distinct from the other previous lines of treatment. cSystemic therapy; Relapsed: complete or partial response, followed by relapse; Refractory: stable disease or progressive disease; Other: missing data or not evaluable. dIf SCT is most recent line, the variable is defined as response to the therapy immediately preceding SCT. DLBCL, diffuse large B-cell lymphoma; ECOG, Eastern Cooperative Oncology Group; GCB, germinal center B-cell; Lonca, loncastuximab tesirine; MCL, mantle cell lymphoma; NHL, non-Hodgkin lymphoma; SCT, stem cell transplant. Safety

TEAE (all grades) by preferred term TEAE (Grade ≥3) by preferred term n (%) n (%) in ≥20% of patients in ≥5% of patients

Any TEAE 37 (100) Any TEAE 23 (62.2)

Thrombocytopenia 11 (29.7) Anemia 4 (10.8)

Anemia 8 (21.6) Neutropenia 4 (10.8)

Fatigue 8 (21.6) Thrombocytopenia 2 (5.4)

Diarrhea 8 (21.6) Fatigue 2 (5.4)

Combination of Lonca plus ibrutinib had manageable toxicity

Data cut: August 20, 2020. Lonca, loncastuximab tesirine; TEAE, treatment-emergent adverse event. Antitumor Activity

Total population: ORR: 62.9% CRR: 31.4% Median treatment duration: 70 days (range 18–379 days)

1 2 GCB DLBCL Non-GCB DLBCL MCL 100 3 Complete response Partial response 4 5 90 6 7 80 8 9 10 70 11 33.3 12 60 13 14 15 50 37.5 16 17 40 31.0 18

Response(%) 19 20 30 21

50.0 Number Patient 22 20 23 24 29.2 27.6 25 Complete response start 10 20.0 26 27 Partial response start 0 28 Stable disease start 29 Non-GCB DLBCL GCB DLBCL All DLBCL MCL 30 Progressive disease or death 31 Censor* 32 33 Last infusion 34 Ongoing ORR (%) 66.7 20.0 58.6 83.3 35 (n/N) (16/24) (1/5) (17/29) (5/6) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 Months since first dose *Censor: patients who discontinue trial due to reasons other than progression or who go onto a different anticancer treatment.

Data cut: August 20, 2020; 35/37 patients were evaluable for efficacy; 1 with GCB DLBCL and 1 with MCL were non-evaluable. CRR, complete response rate; DLBCL, diffuse large B-cell lymphoma; GCB, germinal center B-cell; MCL, mantle cell lymphoma; ORR, overall response rate. Conclusions

Lonca 60 µg/kg plus ibrutinib 560 mg continues to have encouraging antitumor activity and manageable toxicity in patients with R/R DLBCL and with R/R MCL

ORR for all patients was 62.9% • Non-GCB DLBCL 66.7% • GCB DLBCL 20.0% • MCL 83.3%

CRR for all patients was 31.4% • Non-GCB DLBCL 37.5% • GCB DLBCL 0% • MCL 33.3%

Safety data were consistent with those reported previously1

1. Depaus J, et al. EHA 2020. Abstract 1284. CRR, complete response rate; DLBCL, diffuse large B-cell lymphoma; GCB, germinal center B-cell; Lonca, loncastuximab tesirine; MCL, mantle cell lymphoma; ORR, overall response rate; Q3W, every three weeks; R/R, relapsed/refractory. Safety and Antitumor Activity Study Evaluating Loncastuximab Tesirine and Rituximab Versus Immunochemotherapy in Diffuse Large B-Cell Lymphoma

Yuliya Linhares, et al

Poster slides, 62nd ASH Annual Meeting and Exposition, Virtual Meeting, December 5–8, 2020 Phase 3 Study of Lonca-R in R/R DLBCL

This Phase 3, randomized, open-label, two-part, two-arm, global study of Lonca-R versus standard immunochemotherapy in patients with R/R DLBCL (NCT04384484) is currently recruiting patients not suitable for HSCT who have received ≥1 prior therapy

Part 1: non-randomized safety run-in Part 2: randomized, two-arm study

Lonca-R Lonca-R Lonca 150 µg/kg + Lonca 75 µg/kg + R 375 mg/m2 R 375 mg/m2 Lonca-R Lonca-R Randomization Lonca 150 µg/kg + Lonca 75 µg/kg + 1:1 Q3W × 2 Q3W × 6 R 375 mg/m2 R 375 mg/m2 R-GemOx R 375 mg/m2 + Gem 1000 mg/m2 + Q3W × 2 Q3W × 6 Ox 100 mg/m2

Q2W × 8

Target N=20 Target N=330

DLBCL, diffuse large B-cell lymphoma; HSCT, hematopoietic stem cell transplant; Lonca-R, loncastuximab tesirine plus rituximab; R-GemOx, rituximab/gemcitabine/oxaliplatin; Q2W, every 2 weeks; Q3W, every 3 weeks; R/R, relapsed/refractory. Summary of the Lonca Program

Single-agent Lonca produces encouraging and durable responses with acceptable safety in patients with R/R DLBCL who have received ≥2 prior therapies • This includes high-risk patient groups, notably those who had progression after prior CD19-directed CAR-T therapy or HSCT • Previous treatment with Lonca does not prevent responses to subsequent CAR-T therapy1

A BLA has been accepted by FDA for priority review of Lonca in R/R DLBCL after ≥2 prior therapies

Lonca has increased efficacy in combination with other treatments in R/R DLBCL • High response rates are seen in interim data when combining Lonca with Ibrutinib in R/R DLBCL and R/R MCL A confirmatory phase 3 trial comparing Lonca + Rituximab with R-GemOx in R/R DLBCL has commenced • Patients who have received ≥1 prior systemic therapy and are not suitable for HSCT are being enrolled

1. Thapa et al. Blood Adv 2020;4:3850-3852. BLA, biologics license application; CAR-T, chimeric antigen receptor T-cell therapy; DLBCL, diffuse large B-cell lymphoma; FDA, food and drug administration; HSCT, hematopoietic stem cell transplant; MCL, mantle cell lymphoma; R-GemOx, rituximab/gemcitabine/oxaliplatin; R/R, relapsed or refractory. Preliminary Results of a Phase 2 Study of Camidanlumab Tesirine (Cami), a Novel Pyrrolobenzodiazepine-Based Antibody-Drug Conjugate, in Patients With Relapsed or Refractory Hodgkin Lymphoma

Alex F. Herrera, et al

Oral presentation, 62nd ASH Annual Meeting and Exposition Virtual Meeting, December 5–8, 2020 Study Methods

Study design Key inclusion criteria • Single-arm, multicenter, open-label, Phase 2 • R/R cHL trial (NCT04052997) • Aged ≥16 years (USA), ≥18 years (outside USA) Primary objective Secondary objectives • ≥3 prior lines of treatment (≥2 lines if HSCT-ineligible) • Efficacy of single-agent • DoR, CRR, RFS, PFS, – Including brentuximab vedotin and PD-1 blockade Cami by ORRa OS, and % patients • ECOG performance status 0–2 receiving HSCT • Safety

30-minute IV infusion of Cami on Day 1 of each 3-week cycle

45 µg/kg 30 µg/kg Cycles 1 & 2 Cycle 3 onwards, up to 1 yearb

aPer Lugano classification, determined by central review; bOr until discontinuation due to disease progression, unacceptable toxicity, or other reasons; patients deriving clinical benefit at 1 year may be able to continue treatment on a case-by-case basis. CRR, complete response rate; DoR, duration of response; ECOG, Eastern Cooperative Oncology Group; HSCT, hematopoietic stem cell transplantation; IV, intravenous; ORR, overall response rate; OS, overall survival; PFS, progression-free survival; RFS, relapse-free survival.

20 Ongoing Phase 2 Study of Cami in cHL

Characteristic Total (n=51) Enrollment pause due to meeting protocol-specified Sex, n (%) criterion ≥2 cases of GBS or other relevant severe Male 36 (70.6) neurologic toxicity Female 15 (29.4) Age, years, median (min, max) 36 (20–74) Histology No. of patients enrolled Nodular sclerosis cHL 40 (78.4) Median (range) b and treated with Cami Other/unknown/not evaluable 11 (21.6) No. of Cami cycles ECOG status, n (%) at data cut-off 5 (1–11) 0 29 (56.9) 51 1 19 (37.3) 2 3 (5.9) No. prior systemic therapiesc, median (min, max) 7 (3–20) No. of patients previously treated with Disease status after first-line therapy, n (%) d a Relapsed 35 (68.6) brentuximab vedotin and PD-1 blockade Refractorye 12 (23.5) 50 (98.0%) Otherf 4 (7.8) Refractory to last systemic therapy, n (%) 25 (49.0) aOne patient (1/51; 2%) had a protocol deviation of no prior treatment with brentuximab vedotin; bIncludes mixed cellularity and Prior HSCT, n (%) 37 (72.5) lymphocyte-rich cHL, and subtype not specified/unknown; cIncludes prior HSCT; dComplete or partial response followed by relapse; Autologousg 31 (60.8) eStable or progressive disease; fMissing or not evaluable; gIncludes 1 patient with tandem autologous HSCT. Safety analysis set (n=51). Data cut-off: August 24, 2020. Allogeneic 2 (3.9) cHL, classical Hodgkin lymphoma; ECOG, eastern Cooperative Oncology Group; GBS, Guillain–Barré syndrome; PD-1, programmed death 1; HSCT, hematopoietic stem cell transplant Both 4 (7.8)

21 Overall Response Rate for Cami in cHL

ORR (CR+PR) 83.0% (39/47) 100 4.3 NE 95% CI: 69.2, 92.4 90 10.6 2.1 80 PD 70 SD No. of patients No. of patients 60 44.7 PR with CR with PR 50 40 CR

18 (38.3%) 21 (44.7%) Response (%) 30 20 38.3 10 No. of patients who went on to 0 consolidation with HSCTa Cami 45 µg/kgb 5 (10.6%)

aOne further patient had HSCT planned but not confirmed by data cut-off. 4/5 patients received autologous and 1 patient received allogeneic HSCT; b45 μg/kg for 2 cycles, then 30 μg/kg for subsequent cycles. Response assessment per Lugano classification as determined by central review. Efficacy analysis set (n=47); includes patients who started treatment ≥6 weeks before data cut-off with valid post-baseline disease assessment results from independent review or death prior to first scheduled disease assessment per protocol. Data cut-off: August 24, 2020. CI, confidence interval; CR, complete response; HSCT, hematopoietic stem cell transplant; NE, not evaluable; ORR, overall response rate; PD, progressive disease; PR, partial response; SD, stable disease.

22 Safety

Most common TEAEs (≥20% of patients)a Most common Grade ≥3 TEAEs (≥5% of patients)a

Fatigue 26 (51.0) Hypophosphatemia 6 (11.8)

Pyrexia 20 (39.2) Gamma-glutamyltransferase increased 5 (9.8)

Nausea 19 (37.3) Alanine aminotransferase increased 3 (5.9)

Maculopapular rash 18 (35.3) Maculopapular rash 3 (5.9) Headache 14 (27.5)

Pruritus 14 (27.5) • Cases of GBS/polyradiculopathy: 3 (6.4%): Anemia 13 (25.5) o Grade 4 GBS (inflammatory demyelinating polyneuropathyb) b Arthralgia 12 (23.5) o Grade 2 radiculopathy (radiculitis ) o Grade 2 GBS Diarrhea 11 (21.6) • Similar incidence to Phase 1 Gamma-glutamyltransferase increased 11 (21.6) • Study paused per protocol for a safety review • Enrollment resumed after review by DSMB and FDA Rash 11 (21.6)

aPreferred term; bVerbatim term. Safety analysis set (n=51). Data cut-off: August 24, 2020. Data shown as n (%). DSMB, data safety monitoring board; FDA, Food and Drug Administration; GBS, Guillain–Barré syndrome; TEAE, treatment-emergent adverse event, defined as AE occurring or worsening from time of first dose to either 30 days post last dose or start of new anticancer therapy/procedure, whichever occurred first.

23 Summary

Encouraging Phase 2 antitumor activity in patients with R/R cHL receiving single-agent treatment with Cami • Patients were heavily pre-treated and 98.0% had received prior BV and PD-1 blockade • ORR (CR+PR) to treatment was high at 83.0%, and 38.3% of patients had CR

Safety in this Phase 2 preliminary analysis consistent with Phase 1 study • No new safety signals identified • Similar incidence of GBS/polyradiculopathy Enrollment pause lifted after review of safety and efficacy data

Preliminary results for Cami at Phase 2 suggest potential for this agent to fill an unmet need as an easily administered therapeutic for heavily pre-treated patients with cHL who have failed HSCT, BV, and PD-1 blockade

Enrollment in this Phase 2 study continues

BV, brentuximab vedotin; cHL, classical Hodgkin lymphoma; CR, complete response; GBS, Guillain–Barré syndrome; HSCT, hematopoietic stem cell transplant; ORR, overall response rate; PD-1, programmed death 1; PR, partial response.

24