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Sai-Hong Ignatius Ou
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MA 07 - ALK, ROS and HER2 (ID 673)
- Event: WCLC 2017
- Type: Mini Oral
- Track: Advanced NSCLC
- Presentations: 1
- Moderators:Robert C. Doebele, J.C. Ho
- Coordinates: 10/17/2017, 15:45 - 17:30, Room 316
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MA 07.07 - Clinical Outcomes and ALK Resistance Mutations in ALK+ Non-Small Cell Lung Cancer According to EML4-ALK Variant (ID 8255)
16:25 - 16:30 | Author(s): Sai-Hong Ignatius Ou
- Abstract
- Presentation
Background:
Advanced ALK+ non-small cell lung cancers (NSCLCs) are effectively treated with ALK tyrosine kinase inhibitors (TKIs). However, clinical outcomes among patients treated with ALK TKIs vary, and the clinical benefit of TKI therapy is limited due to acquired resistance. To date, emerging data suggest that the specific EML4-ALK variant may impact clinical outcome, but whether variant is associated with mechanisms of TKI resistance is unknown.
Method:
We identified 108 advanced ALK+ NSCLC cases with known ALK fusion variants. Progression-free survival (PFS) on ALK TKIs and resistance mechanisms were retrospectively evaluated according to ALK variant.
Result:
The 108 ALK+ cases consisted of: 42 (39%) EML4-ALK v1 (E13;A20), 8 (7.4%) v2 (E20;A20), 45 (41.7%) v3 (E6;A20), 3 (2.8%) v5 (E2;A20), 4 (3.7%) v5’ (E18;A20), 1 (0.9%) v7 (E14;A20), and 5 (4.6%) non-EML4-ALK variants. Given the small numbers of non-v1/v3 cases, v1 and v3 cases were selected for further analysis. Among the 21 v1 and 25 v3 cases treated with first-line crizotinib, there was no significant difference in PFS (HR = 0.81 [95% CI, 0.42-1.57], p = 0.526). Similarly, there was no difference in PFS on second-generation ALK TKIs among 35 v1 and 35 v3 patients who received ceritinib, alectinib, or brigatinib following first- or later-line crizotinib (HR = 1.32 [95% CI, 0.77-2.26], p = 0.308). Interestingly, among 12 v1 and 17 v3 patients who received the third-generation TKI lorlatinib after failure of a second-generation TKI, v3 was associated with significantly longer PFS than v1 (HR = 0.250 [95% CI, 0.09-0.72], p = 0.006). From our cohort, we identified 11 v3 and 14 v1 post-crizotinib biopsies. No difference was noted in the presence of ALK resistance mutations (27% and 21%, respectively; p = 1.000). In contrast, among 30 v3 and 18 v1 post-second generation TKI biopsies, ALK resistance mutations were more common among v3 vs v1 cases (66% vs 44%, respectively; p = 0.147). Furthermore, the ALK G1202R solvent front mutation occurred more frequently in v3 vs v1 (47% vs 0%, respectively; p = 0.001).
Conclusion:
Our findings suggest that EML4-ALK variants 1 and 3 may not be associated with significantly different PFS outcomes on crizotinib or second-generation ALK TKIs. However, ALK resistance mutations, particularly G1202R, occur more frequently in v3 vs v1 post–second generation TKI. Patients with this variant may therefore derive particular benefit from third-generation, pan-inhibitory ALK TKIs. Larger, prospective studies will be needed to confirm these findings.
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MA 12 - Circumventing EGFR Resistance (ID 665)
- Event: WCLC 2017
- Type: Mini Oral
- Track: Advanced NSCLC
- Presentations: 1
- Moderators:Wan Ling Tan, Nobuyuki Yamamoto
- Coordinates: 10/17/2017, 11:00 - 12:30, F205 + F206 (Annex Hall)
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MA 12.03 - Kinase Fusions as Recurrent Mechanisms of Acquired Resistance in EGFR-Mutated Non-Small Cell Lung Cancer (NSCLC) (ID 10309)
11:10 - 11:15 | Presenting Author(s): Sai-Hong Ignatius Ou
- Abstract
- Presentation
Background:
Resistance invariably develops in EGFR-mutated NSCLC treated with EGFR tyrosine kinase inhibitors (TKI). In approximately 50% of cases, resistance is mediated by the EGFR T790M mutation; however, multiple other mechanisms of resistance have also been described, including case reports of acquired kinase fusions (PMIDs: 26187428, 28089157).
Method:
Hybrid-capture based genomic profiling (FoundationOne® or FoundationACT™) was performed prospectively on DNA isolated from tissue-based FFPE samples or blood-based circulating tumor (ctDNA) samples from NSCLC patients.
Result:
From a dataset of 3,014 unique EGFR-mutated (exon 19 deletion, L858R, G719X, L861Q, or S768I) TKI naïve or relapsed NSCLCs we identified 28 (0.9%) cases with co-occurring likely activating kinase rearrangements (BRAF [12], FGFR3 [5], RET [5], ALK [4], NTRK1 [1], EGFR [1]), including 24 confirmed fusions. Treatment histories were available for 21/28 cases, and prior evidence of EGFR mutation and treatment with an EGFR TKI was evident in 21/21 (100%) cases. In 25/28 cases no other known mechanisms of acquired resistance co-occurred with the primary EGFR mutation and the kinase fusion. The 3 cases with co-occurring known resistance mechanisms (T790M or MET amplification) were those with BRAF rearrangements for which no fusion partner was identified. Additionally, our dataset included 10 paired pre- and post-EGFR TKI treatment samples where the latter sample showed an acquired kinase fusion (4 FGFR3-TACC3, 2 EML4-ALK, 2 CCDC6-RET, 1 AGK-BRAF, 1 TPM3-NTRK1) in addition to the primary EGFR alteration. Notably, in 3/10 paired cases (2 FGFR3 and 1 BRAF) the fusion was acquired in the setting of dropout of an existing T790M mutation.
Conclusion:
Acquired kinase fusions are rare yet recurrent mechanisms of acquired resistance in EGFR-driven NSCLCs, and may be enriched in the setting of resistance to T790M-specific inhibitors. Genomic profiling capable of detecting all classes of genomic alterations, including base substitutions, indels, copy number alterations, and fusions, is warranted at the time of progression on EGFR TKIs, and often provides rationale for treatment in such cases.
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OA 05 - Next Generation TKI (ID 657)
- Event: WCLC 2017
- Type: Oral
- Track: Advanced NSCLC
- Presentations: 1
- Moderators:James Chih-Hsin Yang, Fiona Blackhall
- Coordinates: 10/16/2017, 15:45 - 17:30, Room 301 + 302
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OA 05.06 - Phase 2 Study of Lorlatinib in Patients with Advanced ALK<sup>+</sup>/ROS1<sup>+</sup> Non-Small-Cell Lung Cancer (ID 8573)
16:40 - 16:50 | Author(s): Sai-Hong Ignatius Ou
- Abstract
- Presentation
Background:
Lorlatinib, a selective, potent, brain-penetrant ALK/ROS1 TKI, is active against most known ALK kinase domain mutations. In phase 1 of this ongoing study (NCT01970865), lorlatinib displayed robust clinical activity among patients with ALK[+]/ROS1[+] non-small-cell lung cancer (NSCLC), most of whom were heavily pretreated and had CNS metastases. Phase 2 evaluated efficacy (overall and intracranial), according to prior treatment, and safety at the recommended phase 2 dose (100 mg QD).
Method:
Patients with NSCLC ± asymptomatic CNS metastases enrolled in 6 cohorts (EXP1–5, ALK[+]; EXP6, ROS1[+]). The primary endpoint was objective response rate (ORR) and intracranial ORR by independent central review. Safety, patient-reported outcomes and molecular profiling were also assessed.
Result:
As of 15-March-2017, 227 ALK[+] patients were evaluated for ORR (Table), including 140 with CNS involvement who were evaluated for intracranial ORR.
Of 219 ALK+ patients analyzed for ALK kinase domain mutations at baseline, 46/219 (21%) had ≥1 mutation detected in circulating free DNA; most derived treatment benefit with an ORR of (27/46) 59%. Across all cohorts (N=275), the most common treatment-related adverse events (AEs) and grade 3/4 treatment-related AEs were hypercholesterolemia (81%/16%) and hypertriglyceridemia (60%/16%); 30% and 22% of patients had treatment-related AEs associated with dose interruptions and reductions, respectively. No treatment-related deaths occurred; 7 patients (3%) had treatment-related AEs leading to treatment discontinuation. 157/275 (57%) patients remained on treatment at data cutoff. Most patients reported stable/improved global quality of life (40%/43%).Confirmed ORR Confirmed IC-ORR N n (%) N n (%) ALK[+] cohorts EXP1 (treatment-naïve, no prior ALK-TKIs or CT) 30 27 (90) 8 6 (75) EXP2 (prior crizotinib only) 27 20 (74) 17 10 (59) EXP3 (1 prior ALK TKI ± CT) 59 30 (51) 32 20 (63) EXP3A (prior crizotinib + CT) 32 21 (66) 20 15 (75) EXP3B (any 1 other ALK TKI ± CT) 27 9 (33) 12 5 (42) EXP4 (2 prior ALK TKIs ± CT) 65 27 (42) 45 25 (56) EXP5 (3 prior ALK TKIs ± CT) 46 16 (35) 38 (15 (39) CT, chemotherapy; IC, intracranial.
Conclusion:
Lorlatinib showed clinically meaningful activity, including substantial intracranial efficacy, among ALK[+]/ROS1[+] patients who were either treatment-naïve or failed ≥1 prior ALK TKI. Overall lorlatinib was well tolerated and when needed, AEs were managed by dose delay/reduction or standard medical therapy.
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OA 12 - Emerging Genomic Targets (ID 679)
- Event: WCLC 2017
- Type: Oral
- Track: Advanced NSCLC
- Presentations: 2
- Moderators:H. Akita, Maurice Pérol
- Coordinates: 10/18/2017, 11:00 - 12:30, F203 + F204 (Annex Hall)
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OA 12.06 - Plasma Genomic Profiling and Outcomes of Patients with MET Exon 14-Altered NSCLCs Treated with Crizotinib on PROFILE 1001 (ID 9385)
11:50 - 12:00 | Author(s): Sai-Hong Ignatius Ou
- Abstract
- Presentation
Background:
MET exon 14 alterations occur in ~4% of non-squamous non-small cell lung cancers (NSCLCs). Treatment with the MET inhibitor, crizotinib, achieves confirmed and durable responses in patients with MET exon 14-altered NSCLCs, underscoring the need to test for these drivers (as of August 1, 2016, objective response rate was 39% and median duration of response was 9.1 months). Comprehensive molecular tumor profiling is required to detect MET exon 14 alterations that are highly heterogeneous. The utility of plasma profiling to detect these drivers has not previously been explored in a prospective trial.
Method:
Patients with advanced NSCLCs harboring MET exon 14 alterations by local tumor profiling performed in a CLIA-certified or equivalent environment were treated with crizotinib at 250 mg twice daily on an expansion cohort of the ongoing phase I PROFILE 1001 study (NCT00585195). Objective response was assessed by RECIST v1.0. Prospective plasma profiling of circulating tumor DNA (ctDNA) for MET exon 14 alterations was performed using the PlasmaSELECT64 targeted gene panel (sequencing and analysis output by Personal Genome Diagnostics, Boston MA).
Result:
Plasma samples were obtained for MET exon 14 alteration analysis after study amendment approval in 20 of 52 crizotinib-treated patients, of which 18 samples were deemed sufficient for analysis. MET exon 14 alterations were detected in ctDNA in 11 of 18 patients (61% agreement of plasma ctDNA testing with tumor testing) mapping to the same exon 14 splice site region in 10 of the 11 cases. Of the 11 patients with ctDNA-positive tumors, all were evaluable for response. Of these evaluable patients, a confirmed partial response and stable disease were observed in 2 and 4 patients, respectively.
Conclusion:
MET exon 14 alterations can be detected in plasma ctDNA in a subset of patients with advanced NSCLCs that harbor MET exon 14 alterations by tumor testing. Responses to crizotinib were observed in patients with ctDNA-positive testing for a MET exon 14 alteration. Plasma profiling should be considered as an adjunct to tumor profiling in screening patients for MET exon 14 alterations, pending further confirmation.
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OA 12.08 - Genomic Analysis of Non-Small Cell Lung Cancer (NSCLC) Cases with Focal and Non-Focal MET Amplification (ID 9520)
12:10 - 12:20 | Presenting Author(s): Sai-Hong Ignatius Ou
- Abstract
- Presentation
Background:
MET amplification (METamp) is a known driver and a mechanism of resistance in EGFR-mutated lung cancers treated with targeted therapy. However, development of therapies targeting METamp has been hampered in part due to poor genomic stratification of patients. We investigated the natural distribution of the size of the MET amplicon and associated genomic characteristics.
Method:
Hybrid-capture based comprehensive genomic profiling (CGP) was performed prospectively on DNA isolated from FFPE samples from NSCLC. Tumor mutational burden (TMB) was calculated from 1.1 Mbp of sequenced DNA and reported as mutations/Mb, as previously described (PMID: 28420421).
Result:
We identified 545 NSCLC cases with focal, defined as <20 Mbp (n = 457, 84%), or non-focal (n = 88, 16%) amplification of the MET gene using CGP. Within this set, the size of the MET amplicon ranged from 0.095 – 158 Mbp; 25[th], 50[th] and 75[th] quartiles were 1.63 Mbp, 3.46 Mbp, and 11.66 Mbp, respectively. In cases with focal METamp the median MET copy number was 11, compared to a median of 7 copies for cases with non-focal METamp (P <0.001). Median TMB in cases with focal vs. non-focal METamp was 10.8 and 9.0, respectively (P=0.47). MET exon 14 splice site alterations co-occurred with METamp in 45 cases (8%), of which 80% had focal METamp (median amplicon size of 2.02 Mbp). EGFR mutations co-occurred with METamp in 93 cases (17%) in this dataset, of which 78% had focal METamp (median amplicon size: 3.77 Mbp). In contrast, cases with other co-occurring alterations described in the NSCLC NCCN guidelines (ALK, ROS1 or RET rearrangements, BRAF V600E, or ERBB2 mutations) METamp was more commonly non-focal (3 focal and 6 non-focal cases), with a median amplicon size of 25.5 Mbp. Clinical outcomes will be presented, including a subset of cases in the setting of resistance to EGFR inhibitors.
Conclusion:
The size of the MET amplicon in MET-amplified NSCLCs is largely variable. Focal amplification is associated with a higher estimate of MET copy number. Neither TMB or co-occurring MET or EGFR mutations significantly correlated with size of the MET amplicon; however, other co-occurring known drivers were associated with non-focal METamp. Additional investigation is warranted to determine the clinical significance of the size of the MET amplicon in NSCLC.
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OA 18 - Lung Cancer Pathology and Genetics (ID 687)
- Event: WCLC 2017
- Type: Oral
- Track: Biology/Pathology
- Presentations: 1
- Moderators:George R. Simon, Yoon-La Choi
- Coordinates: 10/18/2017, 14:30 - 16:15, Room 316
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OA 18.03 - Genomic Profiling Reveals Hedgehog Pathway Alterations in Vismodegib Sensitive Lung Squamous Cell Carcinoma (ID 10599)
14:50 - 15:00 | Presenting Author(s): Sai-Hong Ignatius Ou
- Abstract
- Presentation
Background:
The objective response rate of squamous cell carcinoma of the lung (SCCL) to checkpoint inhibitors, as well as the frequency of known NSCLC oncogenic drivers, is low. We performed comprehensive genomic profiling (CGP) on a large set of SCCL cases to identify new opportunities for potential benefit from targeted or immunotherapies.
Method:
Hybrid-capture based CGP of up to 315 genes was performed prospectively on DNA isolated from tissue-based FFPE samples of SCCL, and tumor mutational burden (TMB) was assessed as described previously (PMID: 28420421).
Result:
From a dataset of 958 unique SCCL cases, we identify 2.6% of cases harboring alterations in PTCH1, 0.3% in SMO1, and 01.2% in SUFU, which were primarily mutually exclusive Genes known to be oncogenic drivers in NSCLC were altered at the following frequencies in SCCL 8.0% KRAS, 6.8% EGFR, 3.4% MET, 1.9% BRAF, and less than 1% each for ALK, ROS, and RET. In PTCH1-mutated cases 96% did not harbor alterations in these driver genes (1/23 positive for co-occurrence).. The overall SCCL population has a median TMB of 9.0, with 11.3%) cases higher than 20 mutations/Mb (m/Mb). Two index cases with PTCH1 mutations and no alterations in established NSCLC driver genes were identified. A year 77-year-old male with a 40 pack-year smoking history was diagnosed with metastatic SCCL, basaloid variant, harboring PTCH1 s799fs*29 with TMB of 3.7 m/Mb, and he had a year-long complete response to vismodegib. A 69-year-old male with poorly differentiated SCCL harboring PTCH1 W197* and W460* had a 7 month response to vismodegib. On progression, biopsy of recurrent disease after vismodegib failure demonstrated the same PTCH1 alterations as well as acquisition of the 11q13 (CCND1/FGF3/FGF4/FGF19) amplicon. Both biopsies had TMB > 45 m/mb. Nine additional cases not in this series identified as the basaloid variant of SCCL by expert thoracic pathology review were assayed by CGP and 11% (1/9) harbored PTCH1 mutation, but no other alterations of the hedgehog pathway were identified.
Conclusion:
The index cases presented here suggest a subset of PTCH1-mutated SCCL may see clinical benefit from hedgehog inhibitors, regardless of TMB. In a small series of expert diagnosed basaloid histology in SCCL cases, this histology may enrich for hedgehog pathway alterations. Further investigation of underlying PTCH1 LOH and TMB will be undertaken to assess which SCCL cases can respond to respond to hedgehog pathway inhibitors.
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PC 03 - 3-1 What is the Optimal Sequence of ALK-TKI for ALK-Positive Lung Cancer? (Alectinib First or Crizotinib First) (ID 583)
- Event: WCLC 2017
- Type: Pros & Cons
- Track: Chemotherapy/Targeted Therapy
- Presentations: 1
- Moderators:Rafal Dziadziuszko, Y.O. Tan
- Coordinates: 10/18/2017, 11:00 - 11:40, Room 303 + 304
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PC 03.01 - Crizotinib First (ID 7831)
11:00 - 11:20 | Presenting Author(s): Sai-Hong Ignatius Ou
- Abstract
- Presentation
Abstract:
Crizotinib is the first ALK TKI that has demonstrated statistically superior progression-free survival over standard of platinum-based chemotherapy in treatment-naïve ALK+ NSCLC patients (PROFILE1014, PROFILE 1029). Since then next generation ALK TKI such as ceritinib (ASCEND-4) has also demonstrated statistically improved PFS over platinum-base chemotherapy (ASCEND-4) and alectinib has demonstrated statistically improved PFS over crizotinib (J-ALEX, ALEX). In ALEX, a global randomized phase 3 study comparing alectinib to crizotnib demonstrated that alectinib achieved an median PFS of 25.7 months compared to median PFS of 10.4 months for crizotinib. Additionally, the cumulative incidence of CNS metastasis was significantly lower over for patients treated with alectinib than patients treated with crizotinib the duration of study period. Crizotinib did achieve higher than expected confirmed overall response rate in patients with CNS metastasis in the ALEX trial than has previously published. In fact the median PFS achieved by patients without CNS metastasis at study enrollment and treated by crizotinib was 14.8 months. There is a retrospective study that demonstrated two-third of the patients treated with crizotinib would continue to benefit from continuation of crizotinib beyond disease progression with local ablative therapy with a median overall survival of additional 16 months from the time of disease progression. Next generation ALK inhibitor such as brigatinib has achieved a median PFS of > 15 months in patients who are crizotinib-refractory or intolerant. Furthermore, “third-generation” ALK inhibitor, lorlatinib, achieved clinically meaningful overall response rate presented at this conference. Thus sequencing crizotinib to brigatinib could potentially achieve the additional 15.3 months of additional PFS achieved by using alectinib first. Finally, one of the major resistance mechanism of alectinib is the generation of ALK G1202R solvent front mutation while the incidence of ALK G1202R resistance mutation in crizotinib-refractory cases are much lower. Currently only lorlatinib and TPX-0005 (next generation ALK inhibitors presented at this WCLC) have shown reliably in vitro inhibitory against solvent front mutation. Thus the up-front use of alectinib could potential generate resistance mechanisms that allow limited further treatment options.
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