Virtual Library
Start Your Search
D.B. Costa
Author of
-
+
MO07 - NSCLC - Targeted Therapies II (ID 114)
- Event: WCLC 2013
- Type: Mini Oral Abstract Session
- Track: Medical Oncology
- Presentations: 1
- Moderators:T. John, J.W. Riess
- Coordinates: 10/28/2013, 16:15 - 17:45, Bayside Auditorium B, Level 1
-
+
MO07.02 - Clinical experience with crizotinib in patients with advanced <em>ALK</em>-rearranged non-small cell lung cancer and brain metastases in PROFILE 1005 and PROFILE 1007 (ID 2932)
16:20 - 16:25 | Author(s): D.B. Costa
- Abstract
- Presentation
Background
Crizotinib is an oral tyrosine kinase inhibitor targeting ALK and is approved multinationally for the treatment of advanced ALK-rearranged non-small cell lung cancer (NSCLC) due to its efficacy in controlling systemic tumor burden. The clinical effects of crizotinib in patients with brain metastases have not been previously studied in detail. To evaluate the clinical outcomes of patients with brain metastases on crizotinib, we conducted a retrospective analysis of pooled data from PROFILE 1005 (NCT00932451; a large ongoing global open-label, single-arm phase II study of crizotinib in patients with ALK-rearranged NSCLC who have received one or more treatment regimen for advanced/metastatic disease) and PROFILE 1007 (NCT00932893; an ongoing global randomized phase III study that compared crizotinib with standard second-line chemotherapy [docetaxel or pemetrexed] for advanced ALK-rearranged NSCLC; Shaw et al, N Engl J Med 2013). Subgroup analysis in PROFILE1007 showed that progression-free survival was longer with crizotinib than with chemotherapy for both patients with brain metastases (HR 0.67) and patients without brain metastases (HR 0.43) at baseline.Methods
Patients with previously treated (but ALK-inhibitor-naïve) advanced ALK-rearranged NSCLC enrolled in either PROFILE 1005 or PROFILE 1007 (and randomized to crizotinib) were included in this analysis. Patients with asymptomatic brain metastases were eligible for both studies. The starting dose of crizotinib was 250 mg twice daily. Tumor assessments were evaluated by investigators based on RECIST. Baseline brain imaging (with either computed tomography or magnetic resonance imaging) was required in both studies, and if brain metastases were detected, subsequent brain imaging was required at 6-week intervals. Otherwise, imaging to assess brain metastases on treatment was performed as clinically indicated. Brain metastases were monitored as non-target or target lesions.Results
A total of 275 patients, 31% of 888 patients included in this retrospective analysis, had asymptomatic brain metastases at baseline. Of the 888 patients included, 109 patients (12%) had no prior radiotherapy and 166 patients (19%) had prior radiotherapy for their brain metastases. Among the 109 patients with previously untreated asymptomatic brain metastases, the systemic disease control rate (DCR; % complete responses + partial responses + stable disease) at 12 weeks was 63%, with a systemic objective response rate (ORR) of 53%, and the intracranial DCR at 12 weeks was 56%, with an intracranial ORR of 7%. Among the 166 patients with previously treated brain metastases, the systemic DCR at 12 weeks was 65%, with a systemic ORR of 46%, and the intracranial DCR at 12 weeks was 62% weeks, with an intracranial ORR of 7%. Additional data, including outcomes for patients without brain metastases at baseline, will be presented.Conclusion
In this large retrospective analysis, crizotinib was associated with an initial intracranial DCR of approximately 60% at 12 weeks in patients who were ALK-inhibitor-naïve and had untreated or previously treated brain metastases identified prior to initiation of therapy. Prospective studies may help to determine if crizotinib can delay the natural occurrence or progression of brain metastases in advanced ALK-positive NSCLC.Only Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login, select "Add to Cart" and proceed to checkout. If you would like to become a member of IASLC, please click here.
-
+
MO16 - Prognostic and Predictive Biomarkers IV (ID 97)
- Event: WCLC 2013
- Type: Mini Oral Abstract Session
- Track: Medical Oncology
- Presentations: 1
- Moderators:S. Toyooka, J.C. Yang
- Coordinates: 10/29/2013, 16:15 - 17:45, Parkside Auditorium, Level 1
-
+
MO16.06 - Clinical, structural and biochemical characterization of EGFR exon 20 insertion mutations in lung cancer (ID 745)
16:50 - 16:55 | Author(s): D.B. Costa
- Abstract
- Presentation
Background
Epidermal growth factor receptor (EGFR) exon 20 insertion mutations account for ~10% of EGFR-mutated non-small-cell lung cancer (NSCLC), for the most part occur at the N-lobe of EGFR after its C-helix (after amino-acid M766) and have unsolved patterns of response to ATP-mimetic EGFR tyrosine kinase inhibitors (TKIs).Methods
To understand the patterns of resistance or response to EGFR TKIs of EGFR exon 20 insertion mutations, we decided to study representative mutations using in vitro systems, structural models and also NSCLCs with these specific EGFR mutations.Results
We selected three mutations located within the C-helix (A763_Y764insFQEA [identical to D761_E762insEAFQ], Y764_V765insHH and M766_A767insAI) and four mutations following the C-helix (A767_V769dupASV [identical to V769_D770insASV], D770_N771insNPG, D770_N771insSVD [identical to S768_D770dupSVD] and H773_V774insH [identical to P772_H773insH]) mutations. Our data indicates almost all EGFR exon 20 insertions are resistant to submicromolar concentrations of gefitinib or erlotinib; data that mirrors the lack of clinical response of NSCLCs with these mutations. The crystal structural and enzyme kinetic studies of a prototypical post C-helix EGFR TKI-resistant insertion, between residues D770_N771 (D770_N771insNPG), highlight that these mutations favor the active conformation (i.e., are activating), don’t alter EGFR’s ATP-binding pocket and are less sensitive than TKI-sensitive mutations. D770_N771insNPG is predicted to be 7.66 fold less sensitive than the TKI-sensitive EGFR-L858R. Unexpectedly, we identified the atypical EGFR-A763_Y764insFQEA as the only EGFR exon 20 insertion hypersensitive to EGFR TKIs using enzyme kinetic and cell line models. In patients with EGFR exon 20 mutated NSCLCs, the response rates to gefitinib or erlotinib were significantly higher for A763_Y764insFQEA (2/3; 66.6%) when compared to all other mutations within or following the C-helix (0/17, 0%; p=0.0158). The unorthodox homology model of A763_Y764insFQEA suggests a mechanism of activation (by shifting the register of the C-helix N-terminal) related to TKI-sensitive mutations (such as L858R or L861Q).Conclusion
Our findings not only explain the intricate interplay between different EGFR mutations and their response to EGFR TKIs, but also have clinical implications for the treatment of EGFR exon 20 insertion mutated NSCLCs. Therefore, based on our data and previously published reports the aforementioned mutations affecting amino acids V765 to V774 should be classified as non-sensitizing to the reversible EGFR TKIs gefitinib and erlotinib. Our models may usher the development of EGFR TKIs specific for EGFR exon 20 insertion mutations.Only Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login, select "Add to Cart" and proceed to checkout. If you would like to become a member of IASLC, please click here.
