Repeat Biopsies and the Potential Value of Biologically-Informed Acquired Resistance Therapy Lecia V. Sequist, MD, MPH Associate Professor of Medicine, Harvard Medical School Mary B. Saltonstall Endowed Chair in Oncology, Massachusetts General Hospital

“The magic of EGFR inhibitors”

The promise of genotype-directed therapy Treatment B Treatment C Treatment D Treatment A

The Concept of Oncogene Addiction EGFR PI3K P42/44 MAPK Jak/Stat gefitinib Apoptosis EGFR-Addicted PTEN IGFR K-Ras PI3K MAPK Jak/Stat EGFR Non-addicted case EGFR mutant cancers are “simple”-one RTK controls all downstream signaling.

Dec 2010 TKI max response Acquired Resistance Feb 2010 Diagnosis July 2011 Acq. resist Repeat Biopsy

Clinical Information Biopsy Routine and Molecular Pathology Targeted Therapy

Repeat Biopsies: EGFR mutants with AR to gefitinib, erlotinib 8 Sequist et al Sci Transl Med 2011

Specific TKI Target Alteration RTK mutation or amplification PI3KERKSTAT P P P P P P Two General Classes of TKI Resistance Receptor TK PI3KERKSTAT Sensitive/TKI-naïve RTK2 Receptor TK PI3KERKSTAT RTK1 P RTK2 P Bypass Tracks ? Slide courtesy of Alice Shaw

Sci Transl Med; March consecutive samples with paired pre- and post- AR tissue Comparative analyses for: – Histology with IHC – SNaPshot (most common mutations in 13 genes) – FISH for EGFR and MET amplification

T790M 52% alone 42% with EGFR amp 10% No identified AR mechanism 26% BRAF 2% MET amp 5% SCLC 8% with EGFR amp 1% alone 4% with PI3K 3% Updated MGH cohort: EGFR mutants with AR, n=106 EGFR Amp 15% with T790M 10% alone 4% with SCLC 1% PI3K 5% with SCLC3% alone 2%

Waxing/waning resistance in response to TKI selective pressure Sequist et al, Sci Transl Med 2011

Waxing/waning resistance in response to TKI selective pressure Sequist et al, Sci Transl Med 2011 Adenocarcinoma High-grade neuroendocrine carcinoma

EGFR transformed to SCLC is responsive to SCLC chemo Patient received carboplatin, etoposide and erlotinib

T790M  Most common mechanism of resistance to EGFR TKIs (50-68%)  May have a better prognosis than non- T790M mechanisms (Oxnard, CCR 2010)

gefitinib HKI-272 EKB-569 Drug concentration (  M) Relative cell viability (%) P-AKT P-MAPK Total EGFR P-EGFR Total AKT Total MAPK untreated gefitinib (  M) untreated HKI-272 (  M) NCI-H1975 (L858R and T790M) Overcoming T790M: Irreversible TKIs Kwak, PNAS 102:7665, 2005

Neratinib (HKI-272) – RR 2%, PFS 15 weeks in TKI-resistant patients ( Sequist, JCO 2010 ) Afatinib (BIBW-2992) – RR 7%, PFS ~13 weeks in TKI-resistant pts ( Miller, Lan Onc ‘12 ) Dacomitinib (PF ) – RR 7% in TKI-resistant patients ( Janne, ASCO ’09 ) ….novel T790M-specific TKIs are entering clinical trials – CO-1686 – AP26113 Irreversible TKIs (Pan-HER Inhibitors): Not highly effective for T790M

Afatinib + cetuximab at MTD: Responses by T790M mutation –10 –20 –30 –40 –50 –60 –70 –80 –90 –100 – Patient index sorted by maximum % decrease Maximum percentage decrease from baseline (%) T790M+T790M–EGFR wtUninformative for T790M

PFS at MTD Number at risk Afatinib + cetuximab MTD: Afatinib 40 mg daily + cetuximab 500 mg/m 2 every 2 weeks Estimated PFS4 probability Time from treatment start (months) Median Afatinib + cetuximab MTD = maximum tolerated dose; PSF4 = progression-free survival at 4 months.

AUY922 (Hsp90): best CT response: EGFR-mutant patients (n=25 † /35) EGFR-mutant (n=35) ORR (any PR)7 (20%) ‡ DCR (CR/PR or SD)20 (57%) PFS (18 weeks [95% CI]), % 35.2 (18.7, 52.2) *Confirmed responses; † Patients with at least one post-baseline scan; ‡ Including one PR not confirmed. * * * * * Best % change in target lesions * Felip, et al. ESMO ‘12

EGFR HGF MET TKI Resistance via MET Amplification Engelman et al., Science 2007: 316; 1040.

1/30/08 3/31/08 Pre-Rx ‘08Resistant ‘09 Proof of principle: 63 year old man with an EGFR mutant lung cancer erlotinib Developed Resistance Rx on clinical trial 2/25/09

Met Inhibitors in Clinical Trials ARQ-197, specific MET inhibitor  Randomized phase II of erlotinib +/- ARQ-197 in TKI-naïve patients showed PFS benefit of combo but wasn’t designed to look at EGFR mutants or acquired resistance to EGFR TKIs (Sequist, JCO 2011) Met-mab  Randomized phase II of erlotinib +/- MET-Mab in TKI-naïve paitents showed benefit of combo but again wasn’t designed to look at EGFR mutants or acquired resistance to EGFR TKIs (Spigel, ASCO 2011) XL-184, MET + RET + VEGF  Randomized phase II of erlotinib +/- XL-184 in TKI-resistant patients, completed but not reported yet Crizotinib:  We know it works in MET amp patients, but we don’t know about EGFR mutant,TKI resistant pts with MET amp

Treatment of MET amp pt with Crizotinib Jan 2012March 2012

Clinical Strategies for Patients in the Clinic 1. Repeat biopsies whenever possible 2. Clinical trials whenever possible 3. Treatment beyond progression and local therapy for local progression 4. Continuing TKI beyond with other therapies

Treatment Beyond Progression: appealing if PD is slow Oxnard, et al ASCO’12

Summary and Future Directions Genotype-directed therapy paradigm has revolutionized NSCLC landscape Treatment of resistance has proven complicated Repeat biopsies of patients with AR will continue to greatly supplement lab-based research Prevention may be a potent strategy, especially since pre-disposition toward certain mechanisms may be identifiable. Need more ideal combination regimens Need to develop less-invasive ways of assessing tumor genotype

Acknowledgments MGH Cancer Center Jeff Engelman Alice Shaw Daniel Haber Becca Heist Jerry Azzoli Jennifer Temel Inga Lennes Justin Gainor Panos Fidias Rachel Rosovsky Mike Lanuti Subba Digumarthy Michele Myers Marguerite Parkman Emily Howe MGH Pathology John Iafrate Mari Mino-Kenudson Dora Dias-Santagata Vicente Morales Yale Tom Lynch Scott Gettinger Sarah Goldberg Katie Politi Engelman Lab Tony Faber Matt Niederest Elizabeth Lockerman Vanderbilt William Pao Kadaoki Ohashi Funding Uniting Against Lung Cancer NIH/NCI (R21CA156000) MGH Thoracic Oncology MGH Pathology Stanford Joel Neal UCSF Belinda Waltman Germans Trias i Pujol, Barcelona Teresa Moran Haber/Toner Lab Shyamala Maheswaran Shannon Stott John Walsh James Sullivan Mike Rothenberg