Combinations for Treating EGFR Acquired Resistance Melissa L. Johnson, MD Acquired Resistance Patient Forum In ALK, ROS1 & EGFR Lung Cancers September 6, 2014 | Boston

Combination Treatments for EGFR Acquired Resistance Dx: EGFR+ lung cancer Acquired Resistance Tarceva Tarceva + NEW DRUG Gilotrif Key issue for combination therapies is: do you add the 2nd drug after patients begin to acquire resistance? Or do you start patients on 2 drugs from the beginning and hope the duration of therapy is longer than single agent alone? Gilotrif + NEW DRUG

Can we make 1st Gen TKI Better? Combination Treatments for EGFR Acquired Resistance Can we make 1st Gen TKI Better? We have tried!! Selected approaches to enhancing EGFR TKI in order to overcome or prevent resistance Erlotinib + Chloroquine Erlotinib + Sirolimus Erlotinib + Onartuzumab (anti-Met) Erlotiinb + Entinostat Erlotinib + R1507 (anti IGF-1) Erlotinib + Tivantinib Erlotinib + Sorafanib Erlotinib + Dasatinib Erlotinib + MK2206 (AKT) Erlotinib + MM-121 (anti-ErbB3) Erlotinib + XL184 Erlotinib + Rilotumumab (anti-HGF) Erlotinib + Patritumumab (anti-ErbB3) Erlotinib + AUY-922 (HSP 90 inhibitor) We have tried. Here’s just a representative list, including a trial I led that I’ll mention today. In each case, the drugs added to erlotinib were chosen because there was a rationale, at least in vitro, and usually preclinical data supporting the combinatino after the development of AR. Ill tell you about a couple of these trials—beccause they highlihgt some of the inherent problems of doing combination studies. Slide adapted, courtesy of Thomas J. Lynch, Jr., MD

(erlotinib/afatinib) (erlotinib/afatinib) Combination Treatments for EGFR Acquired Resistance Dx: EGFR+ lung cancer Acquired Resistance Tarceva/Gilotrif (erlotinib/afatinib) + NEW DRUG Tarceva/Gilotrif (erlotinib/afatinib) The second hypothesis is that you combine the two drugs from the beginning and hope the two prolong the existance of AR …we also saw an example of that at this year’s annual meeting…and we’ll talk about that as well.

Flare associated with shorter TTP Combination Treatments for EGFR Acquired Resistance Flare associated with shorter TTP flare 14 of 61 patients (23%, 95% CI 14-35%) had a disease flare (hospitalization or death) Median time from last TKI to flare was 8 days (range 3-21 days) 3 patients went on to trial treatment Chaft, Clin Cancer Res 2011

An “Onco-Chaperone” Inhibitor Combination Treatments for EGFR Acquired Resistance AUY922: An “Onco-Chaperone” Inhibitor This was the strategy we employed for this trial combining erlotinib with HSP90 inhibitor AUY922 Here you see AUY922 in yellow binding deep within the ATP binding pocket of HSP90 shown in blue. HSP90 is a chaperone protein responsible for late-stage maturation, activation and stability in a variety of client proteins. It is important for proper folding and function of both benign but especially malignant proteins. Increased HSP90 expression is associated with a worse prognosis for patients with non-small cell lung cancer (NSCLC) Mutated EGFR is a well established client of HSP90 and there is a large body of pre-clinical data to suggest that HSP90 inhibition might therefore be a reasonable means of targeting AR . AUY922 (in yellow) is a synthetic isoxazole resorcinol HSP90 inhibitor, shown here bound to the deep ATP pocket of HSP90 (in blue) Neckers and Workman Clin Cancer Res 2012 AUY922+ Erlotinib Melissa L. Johnson

Dose of Erlotinib PO daily Combination Treatments for EGFR Acquired Resistance AUY922 + Erlotinib Phase I Dose-Escalation Cohort Dose of AUY922 IV weekly Dose of Erlotinib PO daily # pts enrolled 1 25 mg/m2 75 mg 3 2 150 mg 37.5 mg/m2 4 55 mg/m2 5 70 mg/m2 6 AUY922+ Erlotinib Melissa L. Johnson

HSP90 Inhibitors in Lung Adenocarcinoma Preliminary Activity Patient 01-102 AUY922 25 mg/m + Erlotinib 75 mg Duration of therapy: 6 months C1D1 C1D28 AUY922+ Erlotinib Melissa L. Johnson

AUY922 + Erlotinib Phase II Study Design Stage IV Adenocarcinoma +EGFR mutation Acquired Resistance Biopsy at resistance 30 day erlotinib lead-in Erlotinib 150mg PO qday AUY922 70mg/m2 Key Inclusion Criteria Advanced lung adenocarcinoma EGFR mutation OR previous response to EGFR TKI EGFR TKI for ≥6 months and 1 full month prior to study start Biopsy at time of acquired resistance to EGFR TKI Key Exclusion Criteria Brain metastasis that are symptomatic and/or requiring escalating doses of steroids Systemic treatment within 4 weeks, RT within 2 weeks Primary endpoint: Overall response rate ORR (CR + PR) Secondary endpoints: Progression-free survival, Overall survival, ORR in T790M+, Toxicity Definition of Acquired Resistance19 Previously treated with single-agent EGFR-TKI Tumor harbors TKI-sensitive EGFR mutation (G719X, ex 19 del, L858R, L861Q) EITHER RECIST-defined PR/CR OR ≥ 6 months clinical benefit (SD) with single-agent EGFR-TKI followed by systemic POD Statistical Considerations: stage I: 16 pts (if ≥2 responses, proceed to stage II) stage II: 9 pts (if ≥ 5 responses overall, AUY922 and erlotinib are worthy of further study) α=10%; β=10%; p0=10%; p1=30% Melissa L. Johnson 19 Jackman JCO 2009

Molecular Characteristics N=37 AUY922 25-55 mg/m2 N=12 AUY922 70 mg/m 2 N=25 Primary EGFR mutations EGFR exon 19 deletion 25 10 15 EGFR exon 21 L858R 11 2 9 EGFR exon 21 L861Q: 1 EGFR mutation unknown EGFR T790M found on repeat Tumor Biopsy, n (%) 16 (43%) 6 (50%) 10 (40%) Median duration of EGFR-TKI therapy prior to developing acquired resistance, months (range) 12 (2-42) 13 (8-32) 11(2-42) AUY922+ Erlotinib Melissa L. Johnson

Best Response to AUY922 and Erlotinib Best % change in target lesions Progressive disease Stable disease Partial response EGFR T790M Partial Response (PR): 4/25 (16%)(95% CI 6-35%) Disease Control Rate (DCR): 14/25 (56%)(95% CI 37-73%) AUY922+ Erlotinib Melissa L. Johnson

Individual Responses According to EGFR Mutations and Time on Primary EGFR-TKI Pt ID EGFR 19/21 T790M Best Response AUY922 + Erlotinib Cycles Completed Duration primary EGFR-TKI (prior to AR) 96-501 21 SD 2 7.43 DLT-prolonged QTc; junctional rhythm 96-502 T790M* 1 11.00 Ophthalmologic tox ( gr 2 night blindness) 96-503 19 PR 11.57 Ophthalmologic tox (gr 2 night blindness/blurred) 96-504 — POD 9.57 01-505 L861Q 10.00 96-506 20.80 96-02 25.63 96-03 4.40 96-04 10.10 96-05 3 2.30 96-06 17.87 Patient withdrew consent 96-07 11.93 96-08 12.80 96-09 Unk 8.83 96-10 15.47 96-11 42.00 96-12_ 13 19.80   96-13 25.00 Hepatic tox (gr 3 LFT elevation) 96-14 14.77 Opthalmologic tox (gr 2 night blindness) 96-15 NEΩ 7.50 96-16 6.60 Diarrhea (gr 3 colitis) 96-17 6 10.73 96-18 3.03 96-19 NE∆ 16.63 01-20_ 6.00  POD Reason withdrawn from study Median number of cycles rec’d was 1. Even among pts who had a PR to therapy, med number of cycles was 3. * Small cell transformation patient remains on study

Combination Treatments for EGFR Acquired Resistance Afatinib + Cetuximab Since its discovery, multiple clinical trials have studied therapies for acquired resistance to EGFR TKIs. Single agent second generation EGFR TKIs such as HKI 272 (inh EGFR and HER2), XL 647 (inh EGFR, HER2 and VEGF) an dBIBW an irreversible EGFR inhibitor which also inhibits EGFR, HER2 and HER4 also shown to have activity in transgenic mice with the T790M acquired resistance mutation. None of these agents, tested as single agents in patients with acquired resistance, demonstrating promising results. Targeted agents have also been tested in combination, shown here. Perhaps best shown on this schematic, Once again, every trial produced disappointing results

Combination Treatments for EGFR Acquired Resistance Dual Inhibition of EGFR with Afatinib and Cetuximab in Kinase Inhibitor-Resistant EGFR Mutant Lung Cancer with and without T790M Stop erlotinib/ gefitinib for ≥72 hours3 Disease progression2 Pathology confirmed NSCLC with EGFR mutation1 OR SD 6 months on erlotinib/gefitinib Partial or complete response to erlotinib/gefitinib MTD cohort expanded up to 80 EGFR mutation-positive patients4: 40 T790M+ and 40 T790M– Dose escalation schema 3–6 patients per cohort Afatinib p.o. daily + escalating doses of i.v. cetuximab q 2 weeks Dose levels starting at: afatinib 40 mg + cetuximab 250 mg/m2 Predefined maximum dose: afatinib 40 mg + cetuximab 500 mg/m2 ECOG PS 0-2 Age ≥ 18 years Janjigian, et al. Cancer Discovery 4(9): 1-10, 2014

Tumor Regression by T790M Mutation Status at Recommended Dose Combination Treatments for EGFR Acquired Resistance Tumor Regression by T790M Mutation Status at Recommended Dose Horn at al. IASLC 2011

Janjigian, et al. Cancer Discovery 4(9): 1-10, 2014

Cetux/Afatanib Toxicity Combination Treatments for EGFR Acquired Resistance Cetux/Afatanib Toxicity N=126 All grades Gr 3-4 Rash 114 (90%) 25 (20%) Diarrhea 89 (71%) 8 (6%) Nail Effect 72 (57%) 0 (0%) Stomatitis 71 (56%) 1 (1%) Fatigue 59 (47%) 3 (2%) Nausea 53 (42%) Xerosis Janjigian, et al. Cancer Discovery 4(9): 1-10, 2014

Preliminary Efficacy Comparison Combination Treatments for EGFR Acquired Resistance Preliminary Efficacy Comparison RR T790M + T790M - PFS (months) Tarceva/AUY922 30% 10% 1.7 Afatanib/Cetux 32% 28% 4.66 CO-1686 58% Inc.  AZD 9291 65% 22%

Toxicity Comparison Tarceva/AUY922 Any Grade Diarrhea Rash Unique Toxicities Tarceva/AUY922 95% 81% Night blindness, elevated LFTs, prolongation of QTc Afatanib/Cetux 71% 97% Nail effects, stomatitis Tarceva/Bevacizumab 99% Hypertension, Proteinuria

Combination Treatments for EGFR Acquired Resistance T+A vs T (#8005) Unselected Patient Population BeTa in second line setting ATLAS as maintenance Both with compelling results in enriched populations of never smokers, East Asians Possible EGFR regulation of VEGF in EGFR mutant cell lines (Heymach) phase III Bevacizumab plus Tarceva (BeTa) trial of erlotinib with or without bevacizumab in the second-line treatment of NSCLC patients. The BeTa trial did not reach its primary endpoint of a longer OS time (9.3 months, versus 9.2 months for erlotinib plus placebo; HR, 0.97; 95% CI, 0.80–1.18; p = .75), although the combination resulted in a doubled PFS time (3.4 months, versus 1.7 months for erlotinib plus placebo; HR, 0.62; 95% CI, 0.52–0.75; p < .0001) and response rate (12.6%, versus 6.2% for erlotinib plus placebo; p = .006) with no evidence of greater toxicity beyond that expected with the individual agents alone (Table 2) [77]. The outcomes from the BeTa trial were disappointing because this initial test of the strategy of combining agents with maximal potency against each target turned out to be negative. Perhaps the heterogeneous nature of NSCLC [78] limits our ability to detect benefit from the inhibition of specific targeted pathways in an unselected patient sample. Molecular factors, such as somatic mutations to the EGFR and/or VEGFR signaling pathways may limit the benefits of targeted agents to subsets of patients that have yet to be properly identified [79]. In any case, several additional ongoing phase II and III trials are further exploring the combination of VEGFR and EGFR inhibition in NSCLC

Combination Treatments for EGFR Acquired Resistance JO25567 Study Design Chemotherapy-naïve Stage IIIB/IV NSCLC or postoperative recurrence Non-squamous Activating EGFR mutations* Exon 19 deletion Exon 21 L858R Age ≥20 years PS 0–1 No brain metastasis EB combination Erlotinib 150mg qd + bevacizumab 15mg/kg q3w (n = 75) PD R E monotherapy Erlotinib 150mg qd (n = 75) 1:1 PD All were Asian, median age 67, pts more likely to be female and asian, ex 19 slightly more common than ex 21 mtns Primary endpoint: PFS (RECIST v1.1, independent review) Secondary endpoints: OS, tumor response, QoL, safety Exploratory endpoint: biomarker assessment Stratification factors: sex, smoking status, clinical stage, EGFR mutation type *T790M excluded Abstract 8005: Presented by Terufumi Kato

Primary endpoint: PFS by independent review Combination Treatments for EGFR Acquired Resistance Primary endpoint: PFS by independent review EB E Median (months) 16.0 9.7 HR 0.54 (95% CI: 0.36–0.79) P value* 0.0015 1.0 0.8 *log-rank test, two-sided 0.6 EB E PFS probability 0.4 0.2 9.7 16.0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 Time (months) Number at risk EB 75 72 69 64 60 53 49 38 30 20 13 8 4 4 E 77 66 57 44 39 29 24 21 18 12 10 5 2 1 Abstract 8005: Presented by Terufumi Kato

PFS by EGFR Mutation Type Combination Treatments for EGFR Acquired Resistance PFS by EGFR Mutation Type Exon 19 deletion Exon 21 L858R EB group E group Median (months) 18.0 10.3 HR 0.41 (95% CI: 0.24–0.72) EB group E group Median (months) 13.9 7.1 HR 0.67 (95% CI: 0.38–1.18) 1.0 1.0 0.8 0.8 0.6 0.6 PFS probability PFS probability 0.4 0.4 EB E EB E 0.2 0.2 2 4 6 8 10 12 14 16 18 20 22 24 26 28 2 4 6 8 10 12 14 16 18 20 22 24 26 28 Time (months) Time (months) Number at risk Number at risk EB 40 39 38 36 33 29 27 24 19 12 8 5 2 2 EB 35 33 31 28 27 24 22 14 11 8 5 3 2 2 E 40 35 29 26 22 16 12 9 9 5 3 1 E 37 31 28 18 17 13 12 12 9 7 7 4 2 1 Abstract 8005: Presented by Terufumi Kato

Toxicity with Tarceva + Avastin JO25587 Combination Treatments for EGFR Acquired Resistance Toxicity with Tarceva + Avastin JO25587 No unforeseen toxicities or Rx-related deaths Grade >3 toxicity 91% vs. 53% (esp. HTN, proteinuria) 41% discontinued bevacizumab for adverse effects Primarily proteinuria (15%) or hemorrhagic (12%) Bevacizumab discontinuation rate 10-15% in BeTa, ATLAS trials More toxicity in Japanese patients, longer duration of treatment

EGFR + NSCLC Trials- PFS (months) Combination Treatments for EGFR Acquired Resistance EGFR + NSCLC Trials- PFS (months) Med PFS (mo) LUX- Lung-33 LUX- Lung-64 JO25587- Tarceva5 JO25587- T/A5 EURTAC1 OPTIMAL2 1. Rosell et al. Lancet Oncol. 2012;13:239; 11. Zhou et al. Lancet Oncol. 2011;12:735; 3. Sequist et al. J Clin Oncol. 2013;31:3327; 4. Wu et al. Lancet Oncol. 2014;15:213; 5. Kato, Proc ASCO 2014, A#8005

Combination Treatments for EGFR Acquired Resistance What’s next? Akbay et al. Cancer Discovery 3:1355-1363, 2013

Combination Treatments for EGFR Acquired Resistance Summary TWICE the opportunity for success, but TWICE the side effects Upfront or after the development of Acquired Resistance? Future Directions: Tarceva + PDL-1 inhibitor?