Adjuvant Therapy for Melanoma What is the role of PegIFN in relation to HDIFN? John M. Kirkwood, MD Professor of Medicine, Dermatology and Translational Science University of Pittsburgh School of Medicine &Cancer Institute Melanoma Committee, Eastern Cooperative Oncology Group International Melanoma Working Group kirkwood@pitt.edu

Relapse and Mortality Risk of Operable Melanoma Guides Adjuvant Therapy Local stage I disease: IA-B/IIA Lower risk Primary risk guided by Breslow thickness & ulceration Primary >2mm thick, ulcerated (T3b) or >4 mm (T4) IIB Intermediate risk Regional Stage III Lymph Node Disease: IIIA High risk Sentinel lymph node status: key prognostic assessment for >1 mm thick primaries Risk varies by numbers of nodes involved 1, 2-3, >3 (N1, 2, 3) Microscopic: Stage IIIA 35% relapse risk Macroscopic: Stage IIIB >60% relapse risk IIIB Higher risk Distant Resectable Stage IV Disease: IV Highest risk

Treatment agent/dosage/duration Impact on DFS OS Cooperative group/PI Eligibility   n Treatment agent/dosage/duration Impact on DFS OS NCCTG 837052 Creagan T3-4, N1 262 IFNα2a 20 MU/m2/D IM TIW x3 mos + - ECOG 1684 Kirkwood T4, N1 287 IFNα2b 20 MU/m2/D IVx1 mo 10 MU/m2 SC TIW for 11 mos at 6.9 –12.6 yrs E1690 Intergroup 642 IFNα2b 20 MU/m2/D IVx1 mo 10 MU/m2 SC TIWx11 mos vs 3 MU/D SC TIWx2 yrs at 4.3 – 6.6 yrs WHO #16 Cascinelli N1-2 444 IFNα2a 3 MU/D SC TIWx3 yrs +/- EORTC 18871 Kleeberg 830 IFNα2b 1 MU/D SC QODx1 yr vs IFNg 0.2 mg/D SC QODx1yr E1694 Intergroup Kirkwood 880 IFNα2b 20 MU/m2/D IVx1 mo 10 MU/m2 SC TIWx11 mos vs GMK vaccine x 96 wks at 1.3 –2.1 yrs ECOG 2696 T4, N1, M1 107 GMK + IFN or -->IFN vs GMK at 1.4 – 2.6 yrs UKCCR Aim-High Hancock 674 IFNα2a 3 MU/D SC QODx2 yrs EORTC 18952  Eggermont T4, N1-2 1488 IFNα2b 10MU/d then10 MU TIW x1 or 5 MU TIW x 2 years EORTC 18991  TxN1-2  1256  Peg-IFN alfa-2b SC 6 µg/kg/week (8 weeks) then 3 µg/kg/week (5 years) vs Observation +, +/- at 3.8-7.6 yrs French Grob T2-T4 (≥1.5mm), N0 489 IFNα2a 3 MU SC TIW x 18 mo vs Obs Austrian Pehamberger 311 IFNα2a 3 MU SC QD x 3 wks then TIW x 1 yr vs

Questions Regarding IFN Adjuvant Therapy Relapse free survival benefit (RFS) correlation with overall survival (OS) benefit? Difference by disease/stage burden? Durability of benefit in advanced disease that assures RFS, OS adjuvant impact? Optimal duration of therapy? Dose-response relationship? Role of intravenous IFN induction?

E1684, E1690, and E1694: Durable and Significant Impact upon Relapse-free * and Overall Survival** E1684: IFN vs Observation** E1690: IFN vs Observation* 1.0 HR=1.38 P2=0.02 1.0 HR=1.24 P2=0.09 0.8 0.8 Proportion Alive and Relapse Free 0.6 0.6 Proportion Alive and Relapse Free 0.4 0.4 0.2 0.2 0.0 0.0 2 4 6 8 10 12 14 16 1 2 3 4 5 6 7 8 9 10 Time (Years) Time (Years) Time Interval (Years) Time Interval (Years) 0-2 2-4 4-6 6-8 8-10 0-2 2-4 4-6 6-8 8-10 10-12 12-14 14-16 Observ. 105/212 16/94 5/72 2/44 0/13 Observ. 89/140 12/51 3/39 0/35 1/32 1/29 0/15 0/3 IFN 73/146 14/68 3/53 1/50 2/48 2/44 0/31 0/10 IFN 98/215 15/108 5/85 2/53 0/20 (No. events/No. at risk) (No. events/No. at risk) E1694: IFN vs GMK** 1.0 HR=1.33 P2=0.006 0.8 Proportion Alive and Relapse Free 0.6 0.4 0.2 0.0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 Time (Years) Time Interval (Years) 0-1 1-2 2-3 3-4 4-5 IFN 118/436 28/257 8/123 3/47 0/3 GMK 153/439 40/240 6/113 3/40 0/0 (No. events/No. at risk) Kirkwood et al., J Clin Onc. 1996, 2000, 2001; Clin Cancer Res. 2004;10:1670; Tarhini and Kirkwood J Clin Onc. 2012 5

Rationale for Adjuvant Therapy: Improved Responsiveness of Micro-metastatic Disease IFNα therapy of advanced melanoma: 16% response rate, survival benefit unknown Response inversely correlated with disease burden, durable in one-third Mechanisms unclear; agent pleiotropic IFNα adjuvant therapy: greater impact, relapse/mortality reduced up to 33%

Do Benefits of IFNα Differ by Stage? Trial Benefit Greatest E1684 high tumor burden (N1-2b) E1690 intermediate tumor (N1-2a) E1694 lower tumor burden (T4, N-) benefit across stages with high-dose IFNα 18952 lower burden N1 18991 lower burden N1 18071 lower burden N1 benefit confined to microscopic disease with PegIFN

Meta-analyses of IFN trials demonstrate an impact of IFN on RFS and OS Meta-analysis #RCT RFS OS Comment Ives, JCO. 2007 12 + -/+ ↑ benefit with ↑IFN dose Wheatley, ASCO. 2007 13 OR=0.87, 95% CI=0.81-0.93, p=0.00006 OR=0.9, 95% CI=0.84-0.97, p=0.008 OS benefit of 3% (CI 1%-5%) at 5 yrs Mocellin, JNCI. 2010 14 HR = 0.82, 95% CI = 0.77-0.87; P < .001 HR = 0.89, 95% CI=0.83-0.96; P = .002 18% DFS benefit 11% OS benefit

IFNα as Paradigm for Adjuvant Therapy Relapse-free benefit in all regimens intermediate dose impact is transient HDI impact is durable to >10+ years Survival improved in 2 of 14 trials HDI only demonstrates OS benefit Mechanisms evaluated for HDI, IDI: anti-angiogenic(-/?), pro-apototic(-/?), immunological (+/?)

E1697 Intergroup Trial of 1 month IFNα2b Recent Trials Address Duration of Therapy Required and Role of Induction E1697 Intergroup Trial of 1 month IFNα2b No benefit of 1 month IFN compared to Observation in 1150 patients with Stage II-III melanoma (Agarwala et al., Proc ASCO 2011) EORTC 18991 Trial of 5 years PegIFNα2b Relapse reduction without improved survival at 7.6 years follow-up (Eggermont JCO 2012) Benefit among N1 (microscopic~IIIA), not N2 (IIIB) Treatment tolerated a median of ~14 months

Is there evidence for benefit of prolonged therapy EORTC 18991: Pegylated IFN-a2b x 5 years vs. Observation in Resected Stage III (TxN1-2M0) Melanoma Patients (n=1,256): Resected TxN1-2M0 melanoma, within 7 weeks of lymphadenectomy Observation Randomization Stratified by: Microscopic (N1) vs. palpable (N2) 1 vs. 2-4 vs. 5+ nodes Breslow Ulceration Gender and site Peg-IFN alfa-2b for up to 5 years Induction (8 weeks) 6 µg/kg/week Maintenance (5 years or distant metastasis) 3 µg/kg/week Dose reduction to 3, 2, 1 to maintain performance status Primary Endpoints: Relapse-free survival (RFS) Distant metastasis-free survival (DMFS) Eggermont AM, et al. Lancet 2008; 372: 117–26 J Clinical Oncology 2012

RFS benefit of adjuvant peginterferon maintenance sustained at 7 RFS benefit of adjuvant peginterferon maintenance sustained at 7.6 years follow-up No change in DMFS or OS observed from 2007 to 2011 EORTC 18991: Outcome at 7.6 yrs. Is diminished compared with 3.8 yrs. maturity RFS benefit diminished at 7.6 years No significant impact upon DMFS or OS early or at maturity Outcome (ITT) 2007 2012 HR (95% CI) P Value HR (95% CI)* RFS 0.82 (0.71-0.96) .01 0.87 (0.76-1.00) .05 DMFS 0.88 (0.75-1.03) .11 0.93 (0.81-1.07) .33 OS 0.98 (0.82-1.16) .78 0.96 (0.82-1.11) .57

EORTC 18991: Outcome in N1 population in 2007, 2012 Stage III N1 disease showed significant RFS and DMFS in 2007 Improvements at 7.6 years are no longer statistically significant Outcome in N1 Population 2007 2012 HR P Value HR (99% CI)* RFS 0.73 .016 0.82 (0.61-1.10) .08 DMFS 0.75 .034 0.86 (0.63-1.17) .22 OS 0.88 .43 0.86 (0.62-1.21) .26

EORTC 18991: N2 population lacks benefit at either 3. 8 or 7. 6 yrs EORTC 18991: N2 population lacks benefit at either 3.8 or 7.6 yrs. evaluation Patients with stage III N2 show no significant benefit in any endpoint Outcome in N2 2007 Evaluation 2012 Evaluation HR P Value HR (99% CI)* RFS 0.86 .12 0.89 (0.71-1.13) .21 DMFS 0.94 .53 0.96 (0.76-1.22) .66 OS 1.01 .91 1.00 (0.78-1.29) .97

EORTC 18991: Stage III N1, Ulcerated Disease Greatest benefit of Peg IFN in Stage III N1 subset, ulcerated primary Median OS peg IFN vs. observation: > 9 vs. 3.7 years EORTC 18081 trial compares Peg IFN x 2 yrs vs. observation in patients with ulcerated primary tumors Outcome in 2007 in Patients With Stage III N1, Ulcerated Primary HR (99% CI) P Value RFS 0.72 (0.46-1.13) .06 DMFS 0.65 (0.41-1.04) .02 OS 0.59 (0.35-0.97) .006

EORTC 18991: Primary Tumor Ulceration** Primary tumor ulceration is associated with trend to IFN benefit:* OS Outcome in 2011 Based on Primary Tumor Ulceration HR (99% CI) P Value Ulcerated 0.81 (0.58-1.14) .11* Not ulcerated 1.05 (0.79-1.41) .64 *not significant at maturity in 2012; **US Intergroup trials have never shown this correlation

Summary of IFNα trials leading to regulatory approval Study/PI Stage N Treatment agent/ dosage/duration Median Follow up (year) Impact on (%) Toxicity Attrition Rate Comment PFS   OS E1684 Kirkwood T4, N+ 287 IFNα2b 20 MU/m2/D IV for 1 month. Then, 10 MU/m2 SC TIW for 11 months vs. Observation 6.9 0.61; p=.001 0.67; p=.01 26 At 12.6 yr, the impact of competing causes of death on OS cannot be ignored 12.6 0.72; p=.02 0.82; p=.18 E1690 642 IFNα2b 20 MU/m2/D IV for 1 month. Then, 10 MU/m2 SC TIW for 11 months vs.  3 MU/D given SC TIW for 2 years vs. Observation 4.3 0.78; p=.05 1.0 13 Cross over of observation pts to HDI at nodal relapse (n=38 pts) is expected to affect OS analysis  6.6  0.81; p=0.09 E1694 Kirkwood 880 IFNα2b 20 MU/m2/D IV for 1 month. Then 10 MU/m2 SC TIW for 11 months vs. GMK vaccine for 96 wks 1.3 p=.0004 p=.023 10 Symmetrical impact upon RFS, OS for IFN over GMK led to early closure for vaccine futility at 2 yr  2.1 0.75; p=.006 0.76; p=.04 EORTC 18991  Eggermont N1-2 1256 PegIFNα2b given SC at 6 µg/kg/week (8 weeks) then 3 µg/kg/week (5 years) vs. Observation 3.8 P=.011 0.98 37 No impact upon OS, or DMFS at initial reporting or mature publication  7.6 0.87; P=0.055 .96 Tarhini and Kirkwood J Clin Oncol 2012

Biomarkers of Risk & Benefit are Needed to Tailor and Improve Adjuvant Therapy Risk/Prognosis S100B may add to risk assessment (Tarhini et al., J. Clin Onc 2008) Benefit: Predictors of IFN clinical benefits Autoimmunity (Gogas, et al., NEJM 2006) Cytokine profile in serum (Yurkovetsky, 2007) Ulceration of primary tumor (Ives, 2007) Inflammatory profile in tumor (Gajewski, 2011)

Conclusions: IFNα Adjuvant Therapy Relapse-free survival benefit HR ~.70 correlates with overall survival benefit Disease/stage burden predicts PegIFN benefit, but not HDI benefit Duration of therapy feasible with HDI & PegIFN are both ~1 year Dose-response relationship still unclear Adjuvant recommendation should be HDI If HDI not tolerated, and disease is of stage <IIIA, PegIFN is a fallback option