Presentation on theme: "The Therapeutic Implications of EML4/ALK, ROS-1 and Other New Biomarkers Lyudmila Bazhenova, MD Associate Clinical Professor Lung Cancer Unit Leader UC."— Presentation transcript:
The Therapeutic Implications of EML4/ALK, ROS-1 and Other New Biomarkers Lyudmila Bazhenova, MD Associate Clinical Professor Lung Cancer Unit Leader UC San Diego Moores Cancer Center
Objectives Review current state of targetable lung cancer biomarkers Review and contrast clinical characteristics of patients with EML4-ALK, ROS 1, and KIFB5-RET fusion protein, testing strategies and agents with clinical activity.
Mechanism of Action of ALK, ROS1 and RET Fusion Oncogenes All three are receptor tyrosine kinases (RTK) ALK and RET are capable of homodimerization and self (ligant independend) activation Mechanism of self activation of ROS1 is being debated Downstream signaling via RAS/ERK (proliferation), and PI3K/AKT and JAK/STAT( resistance to apoptosis)
Testing for Fusion Oncogenes Amount of protein on the surface of the cell IHC expression F F Break apart FISH RT-PCR
Echinoderm microtubule associated protein-like 4 anaplastic lymphoma kinase ? Adapted from Soda et al. Nature; 2007. NC
ALK Fusion Variants Sasaki, European Journal of Cancer; 2010.
Methods of ALK Detection FISH break apart –Pros: independent of FPE –Cons: if inversion involves a small locus of 2p it could be false negative; can not distinguish variants; cut of is 15% of nuclei with split signal; low throughput RT-PCR –Pros: Rapid detection and identification of each unique variant –Cons: False negatives; Loss of RNA during de parafinization; has to be multiplexed, i.e probes to all known variants. Unknown variants will not be detected. IHC –Pros: easy –Cons: several antibodies have been developed which look promising as a screening tool. No commercially available IHC in the US. VENTANA just received an approval in China with 93% concordance with FISH, sensitivity 100%, specificity 98%
EML4-ALK Fusion Patients: younger, non smokers, with adenocarcinoma, adenosquamous carcinoma and rarely SCC Frequency: 4% in all, 33% in EGFR negative never smokers Biology: 16 EML4-ALK variants have been identified in NSCLC. Clinical significance of each variant is unknown. Testing: Visys break apart FISH (> 15% cells with split signal in 50 nuclei scored). –ALK PCR, IHC Therapy: crizotinib 1 Shaw AT, ASCO; 2010; 2 Kris MG. ASCO 2011; abstract CRA7506. 3 Rodig SJ, Clin Cancer Res; 2009;15 Soda M, et al. Nature; 2007;448
Some degree of tumor shrinkage 90% ORR - 60.8% DCR - 82.5% at week 8 Median time to response 7.9 weeks (2.1 - 39.6 weeks) Median response duration 49.1 weeks Median PFS 9.7 months (95% CI 7∙7–12∙8) N=149 Clinical Efficacy of Crizotinib Unknown… How crizotinib compares to chemotherapy 1 st line QOL OS TTP Camidge, Lancet oncology 13, 2012
1 st Line or Second Line No studies examining the best placement of the drug. FDA approved the drug without mentioning the line of therapy. One can make a leap of faith from EGFR inhibitors and use it in the first line. Profile 1007 compared crizotinib to 2 nd line chemotherapy –PFS 7.7 m vs. 3 m in favor of crizotinib (HR 0.49; 95% CI, 0.37 to 0.64; P<0.001) –RR 65% vs. 20 % in favor of crizotinib ( p<0.001) –OS not different, 64% of patients in chemotherapy arm received crizotinib –QOL: greater reduction of symptoms and delay in new symptoms on crizotinib arm. Profile 1014 will compare crizotinib to 1 st line chemotherapy. Shaw NEJM ;June 2013
Characteristics of Progression Patients were allowed to stay on the study post progression if they continued to derive clinical benefi Median duration of treatment 43.1 m (Range 0.1-136.8) 69/149 patients had disease progression at the data cut off. –39 continued to receive crizotinib for at least 2 weeks post progression 12 of them did that for 6 months Range of post progression treatment is 21 to 591 days. –Most common new sites of progression were brain ( N=10), lung (n=5), liver ( N=3) Camidge, Lancet oncology 13, 2012.
Duration of Initial Response and Post Progression Therapy
Management of Crizotinib Resistance Local treatment with radiation for locally progressing disease –Clonal evolution Platinum based doublet or triplet Second generation ALK inhibitors –AP26114 –LDK378 –CH5424802 (RG7853) HSP 90 inhibitors
Oncogenic ROS1 First described fusion gene FIG-ROS1 was found in glioblastoma –240kb deletion on 6p21q resulting in a fusion gene coding for oncogenic fusion protein. –Short and long isoforms –Induce tumorigenesis in xenograft mouse models Also expressed in cholangiocarcinoma in 8.7% and ovarian cancer in 0.5%, gastric and colon, myofibroblastic tumors and angiosarcoma EZR–ROS1 fusion gene has been shown to promote lung adenocarcinoma when ectopically expressed in lung epithelium Gu TL, PLoS One; 2011. Birch AH, PLoS One; 2011; Lee, Cancer; May 2013 Bergethon et al. JCO; 2012 (30)8.
ROS 1 Fusion Gene Arai, PLOS ONE; February 2013.
ROS1 Fusion Patients: Younger, never smokers, adenocarcinoma, high grade histology Frequency: 1.2 -1.7% in all Biology: 9 variants have been identified in NSCLC so far –Clinical significance is unknown. Mechanism of activation is different. –FIG-, CD74-, SCL34A2-, TPM3-, SDC4-, EZR-, LRIG3, KDELR2–, and CCDC6– Testing: Visys break apart FISH (> 15% cells with split signal in 50 nuclei scored) –ROS PCR, IHC Therapy: crizotinib Shaw AT, JCO 2012;30:(suppl; abstr 7508) Ou, Exp revi. of anticancer therapy 2012,;12 Gu TL, PLoS One. 2011; 6:e15640. Birch AH, PLoS One. 2011; 6:e28250 Lee, Cancer May 2013 Davis Clin Cancer Res. Sep 2012 Bergeron, JCO, 30, 2012
Methods of ROS1 Detection RT-PCR –Cons: False negatives; 9 variants have been described in a matter of 12 months. Has to be multiplexed, i.e., probes to all known variants. Unknown variants will not be detected. FISH break apart –Cons: if inversion involves a small locus it could be false negative; can not distinguish variants; cut of is 15% of nuclei with split signal; low throughput IHC –Cons: not commercially available, several antibodies appear promising
Response of a ROS1 Positive Patient to Crizotinib 49% homology in the TK domain and ATP binding site Crizotinib is active in ROS1 fused cell cultures Bergeron, JCO, 30, 2012. Baseline 12 weeks
Clinical Validation of ROS1 as a Therapeutic Target 14 patients enrolled in phase I study Safety/efficacy of crizotinib 250mg bid ROS1 rearrangement by FISH Negative for ALK rearrangement Average 54 yo, 13/14 never smokers 80% received prior therapy 8/14 responded (57%) Shaw et al. JCO. 2012, 30 (suppl; abstr 7508.)
Methods of RET Detection RT-PCR –Cons: False negatives; 3 variants have been described in a matter of 12 months. Has to be multiplexed, i.e probes to all known variants. Unknown variants will not be detected. FISH break apart –Cons: if inversion involves a small locus it could be false negative; can not distinguish variants; cut of is 15% of nuclei with split signal; not widely available; low throughput IHC –Current IHC antibodies do not correlate with RET fusion
RET Fusion Patients: AdenoCA and adenoSCC carcinoma, never or former smokers, poor differentiation ?, earlier LN metastases Frequency: –1.4% in all, –5.6 % in “triple negative”( EGFR, ALK, KRAS) –6.3% in non smokers negative for EGFR, KRAS, ALK, HER2, BRAF, and ROS1 –16% in non smokers negative for EGFR, KRAS, ALK, ROS1, NRAS, BRAF, HER2, PIK3CA, MEK1, and AKT Biology: 4 variants have been identified in NSCLC so far –Clinical significance is unknown. –KIF5B-, CCDC6-, NCOA4-. TRIM33 Ju YS, Genome Res, 2012 Drilon, Cancer Discover March 2013 Wang R, J Clin Oncol 30: 2012 Kohno, Cancer Science Aug 2013
RET Fusion Gene Testing: Visys break apart FISH (> 15% cells with split signal in 50 nuclei scored) –RET PCR Therapy: Unknown –Sunitinib, Sorafenib, Vandetanib, Carbozatinib, Ponatinib, and Lenvatinib all have potential for activity –All active in KIF5B-RET–transformed cell lines –Last 4 are in formal clinical trials
Clinical Activity of Carbozatinib in RET Fused Patients 4 weeks Drilon, Cancer Discover March 2013.
Summary ALKROSRET Discovery2007 2012 Type of the product Receptor tyrosine kinase Frequency4%1.7%1.4% HistologyAdenoCA, AdenoSCC, SCC AdenoCA Poorly differentiated AdenoCA AdenoSCC Poorly differentiated? Other characteristics Never smokers, younger Approved agentCrizotinibNone Agent in consideration CrizotinibSunitinib Sorafenib Carbozatinib Vandetanib Ponatinib Lenvatinib
HER 2 Insertions Patients: Adenocarcinomas, never smokers Frequency: Incidence 2.8-4.2% Biology: –In-frame insertions into exon 20. Transgenic mouse models confirm oncogenicity Therapy: –Drugs of interest: neratinib, afatinib, dacomitinib Preclinical models show synergy with mTOR inhibitors. Clinical trial of neratinib + temsirolimus ongoing, several PR are reported Both afatinib and dacomitinib have case reports of responses
BRAF Mutations Patients: smokers and non smokers Frequency: 1.6-3% Biology: majority of the mutations are non V600E (more likely in smokers), V600E ( more likely in never smokers) Therapy: –One case report or a NSCLC patient with V600E patient responding to vemurafenib –Dabrafenib is being tested in patients with V600E NSCLC –MEK inhibitors are being considered for non V600E patients