Yuri Rukazenkov

Biomarker Analyses and Final Overall Survival Results From a Phase III, Randomized, Open-Label, First-Line Study of Gefitinib Versus Carboplatin/Paclitaxel in Clinically Selected Patients With Advanced Non–Small-Cell Lung Cancer in Asia (IPASS)

PURPOSE The results of the Iressa Pan-Asia Study (IPASS), which compared gefitinib and carboplatin/paclitaxel in previously untreated never-smokers and light ex-smokers with advanced pulmonary adenocarcinoma were published previously. This report presents overall survival (OS) and efficacy according to epidermal growth factor receptor (EGFR) biomarker status. PATIENTS AND METHODS In all, 1,217 patients were randomly assigned. Biomarkers analyzed were EGFR mutation (amplification mutation refractory system; 437 patients evaluable), EGFR gene copy number (fluorescent in situ hybridization; 406 patients evaluable), and EGFR protein expression (immunohistochemistry; 365 patients evaluable). OS analysis was performed at 78% maturity. A Cox proportional hazards model was used to assess biomarker status by randomly assigned treatment interactions for progression-free survival (PFS) and OS. RESULTS OS (954 deaths) was similar for gefitinib and carboplatin/paclitaxel with no significant difference between treatments overall (hazard ratio [HR], 0.90; 95% CI, 0.79 to 1.02; P = .109) or in EGFR mutation-positive (HR, 1.00; 95% CI, 0.76 to 1.33; P = .990) or EGFR mutation-negative (HR, 1.18; 95% CI, 0.86 to 1.63; P = .309; treatment by EGFR mutation interaction P = .480) subgroups. A high proportion (64.3%) of EGFR mutation-positive patients randomly assigned to carboplatin/paclitaxel received subsequent EGFR tyrosine kinase inhibitors. PFS was significantly longer with gefitinib for patients whose tumors had both high EGFR gene copy number and EGFR mutation (HR, 0.48; 95% CI, 0.34 to 0.67) but significantly shorter when high EGFR gene copy number was not accompanied by EGFR mutation (HR, 3.85; 95% CI, 2.09 to 7.09). CONCLUSION EGFR mutations are the strongest predictive biomarker for PFS and tumor response to first-line gefitinib versus carboplatin/paclitaxel. The predictive value of EGFR gene copy number was driven by coexisting EGFR mutation (post hoc analysis). Treatment-related differences observed for PFS in the EGFR mutation-positive subgroup were not apparent for OS. OS results were likely confounded by the high proportion of patients crossing over to the alternative treatment.

Osimertinib in Untreated EGFR-Mutated Advanced Non–Small-Cell Lung Cancer

Background Osimertinib is an oral, third‐generation, irreversible epidermal growth factor receptor tyrosine kinase inhibitor (EGFR‐TKI) that selectively inhibits both EGFR‐TKI–sensitizing and EGFR T790M resistance mutations. We compared osimertinib with standard EGFR‐TKIs in patients with previously untreated, EGFR mutation–positive advanced non–small‐cell lung cancer (NSCLC). Methods In this double‐blind, phase 3 trial, we randomly assigned 556 patients with previously untreated, EGFR mutation–positive (exon 19 deletion or L858R) advanced NSCLC in a 1:1 ratio to receive either osimertinib (at a dose of 80 mg once daily) or a standard EGFR‐TKI (gefitinib at a dose of 250 mg once daily or erlotinib at a dose of 150 mg once daily). The primary end point was investigator‐assessed progression‐free survival. Results The median progression‐free survival was significantly longer with osimertinib than with standard EGFR‐TKIs (18.9 months vs. 10.2 months; hazard ratio for disease progression or death, 0.46; 95% confidence interval [CI], 0.37 to 0.57; P<0.001). The objective response rate was similar in the two groups: 80% with osimertinib and 76% with standard EGFR‐TKIs (odds ratio, 1.27; 95% CI, 0.85 to 1.90; P=0.24). The median duration of response was 17.2 months (95% CI, 13.8 to 22.0) with osimertinib versus 8.5 months (95% CI, 7.3 to 9.8) with standard EGFR‐TKIs. Data on overall survival were immature at the interim analysis (25% maturity). The survival rate at 18 months was 83% (95% CI, 78 to 87) with osimertinib and 71% (95% CI, 65 to 76) with standard EGFR‐TKIs (hazard ratio for death, 0.63; 95% CI, 0.45 to 0.88; P=0.007 [nonsignificant in the interim analysis]). Adverse events of grade 3 or higher were less frequent with osimertinib than with standard EGFR‐TKIs (34% vs. 45%). Conclusions Osimertinib showed efficacy superior to that of standard EGFR‐TKIs in the first‐line treatment of EGFR mutation–positive advanced NSCLC, with a similar safety profile and lower rates of serious adverse events. (Funded by AstraZeneca; FLAURA ClinicalTrials.gov number, NCT02296125.)

Final Overall Survival: Fulvestrant 500 mg vs 250 mg in the Randomized CONFIRM Trial.

Background At the time of the initial analysis of overall survival (OS) for the Comparison of Faslodex in Recurrent or Metastatic Breast Cancer (CONFIRM) randomized, double-blind, phase III trial, approximately 50% of patients had died. A final analysis of OS was subsequently planned for when 75% of patients had died. Methods Patients were randomly assigned 1:1 to fulvestrant 500 mg administered as two 5-mL intramuscular injections on days 0, 14, and 28 and every 28 (±3) days thereafter or fulvestrant 250 mg administered as two 5-mL intramuscular injections (one fulvestrant and one placebo [identical in appearance to study drug]) on days 0, 14 (two placebo injections only), and 28 and every 28 (±3) days thereafter. OS was analyzed using an unadjusted log-rank test. No adjustments were made for multiplicity. Serious adverse events (SAEs) and best response to subsequent therapy were also reported. All statistical tests were two-sided. Results In total, 736 women (median age = 61.0 years) were randomly assigned to fulvestrant 500mg (n = 362) or 250mg (n = 374). At the final survival analysis, 554 of 736 (75.3%) patients had died. Median OS was 26.4 months for fulvestrant 500mg and 22.3 months for 250mg (hazard ratio = 0.81; 95% confidence interval = 0.69–0.96; nominal P = .02). There were no clinically important differences in SAE profiles between the treatment groups; no clustering of SAEs could be detected in either treatment group. Type of first subsequent therapy and objective responses to first subsequent therapy were well balanced between the two treatment groups. Conclusions In patients with locally advanced or metastatic estrogen receptor–positive breast cancer, fulvestrant 500mg is associated with a 19% reduction in risk of death and a 4.1-month difference in median OS compared with fulvestrant 250mg. Fulvestrant 500mg was well tolerated, and no new safety concerns were identified.

Fulvestrant 500 mg Versus Anastrozole 1 mg for the First-Line Treatment of Advanced Breast Cancer: Overall Survival Analysis From the Phase II FIRST Study

Purpose To compare overall survival (OS) for fulvestrant 500 mg versus anastrozole as first-line endocrine therapy for advanced breast cancer. Patients and Methods The Fulvestrant First-Line Study Comparing Endocrine Treatments (FIRST) was a phase II, randomized, open-label, multicenter trial. Postmenopausal women with estrogen receptor–positive, locally advanced/metastatic breast cancer who had no previous therapy for advanced disease received either fulvestrant 500 mg (days 0, 14, 28, and every 28 days thereafter) or anastrozole 1 mg (daily). The primary end point (clinical benefit rate [72.5% and 67.0%]) and a follow-up analysis (median time to progression [23.4 months and 13.1 months]) have been reported previously for fulvestrant 500 mg and anastrozole, respectively. Subsequently, the protocol was amended to assess OS by unadjusted log-rank test after approximately 65% of patients had died. Treatment effect on OS across several subgroups was examined. Tolerability was evaluated by adverse event monitoring. Results In total, 205 patients were randomly assigned (fulvestrant 500 mg, n = 102; anastrozole, n = 103). At data cutoff, 61.8% (fulvestrant 500 mg, n = 63) and 71.8% (anastrozole, n = 74) had died. The hazard ratio (95% CI) for OS with fulvestrant 500 mg versus anastrozole was 0.70 (0.50 to 0.98; P = .04; median OS, 54.1 months v 48.4 months). Treatment effects seemed generally consistent across the subgroups analyzed. No new safety issues were observed. Conclusion There are several limitations of this OS analysis, including that it was not planned in the original protocol but instead was added after time-to-progression results were analyzed, and that not all patients participated in additional OS follow-up. However, the present results suggest fulvestrant 500 mg extends OS versus anastrozole. This finding now awaits prospective confirmation in the larger phase III FALCON (Fulvestrant and Anastrozole Compared in Hormonal Therapy Naïve Advanced Breast Cancer) trial (ClinicalTrials.gov identifier: NCT01602380).

Osimertinib As First-Line Treatment of EGFR Mutation–Positive Advanced Non–Small-Cell Lung Cancer

Purpose The AURA study ( ClinicalTrials.gov identifier: NCT01802632) included two cohorts of treatment-naïve patients to examine clinical activity and safety of osimertinib (an epidermal growth factor receptor [EGFR] -tyrosine kinase inhibitor selective for EGFR-tyrosine kinase inhibitor sensitizing [ EGFRm] and EGFR T790M resistance mutations) as first-line treatment of EGFR-mutated advanced non-small-cell lung cancer (NSCLC). Patients and Methods Sixty treatment-naïve patients with locally advanced or metastatic EGFRm NSCLC received osimertinib 80 or 160 mg once daily (30 patients per cohort). End points included investigator-assessed objective response rate (ORR), progression-free survival (PFS), and safety evaluation. Plasma samples were collected at or after patients experienced disease progression, as defined by Response Evaluation Criteria in Solid Tumors (RECIST), to investigate osimertinib resistance mechanisms. Results At data cutoff (November 1, 2016), median follow-up was 19.1 months. Overall ORR was 67% (95% CI, 47% to 83%) in the 80-mg group, 87% (95% CI, 69% to 96%) in the 160-mg group, and 77% (95% CI, 64% to 87%) across doses. Median PFS time was 22.1 months (95% CI, 13.7 to 30.2 months) in the 80-mg group, 19.3 months (95% CI, 13.7 to 26.0 months) in the 160-mg group, and 20.5 months (95% CI, 15.0 to 26.1 months) across doses. Of 38 patients with postprogression plasma samples, 50% had no detectable circulating tumor DNA. Nine of 19 patients had putative resistance mechanisms, including amplification of MET (n = 1); amplification of EGFR and KRAS (n = 1); MEK1, KRAS, or PIK3CA mutation (n = 1 each); EGFR C797S mutation (n = 2); JAK2 mutation (n = 1); and HER2 exon 20 insertion (n = 1). Acquired EGFR T790M was not detected. Conclusion Osimertinib demonstrated a robust ORR and prolonged PFS in treatment-naïve patients with EGFRm advanced NSCLC. There was no evidence of acquired EGFR T790M mutation in postprogression plasma samples.

Epidermal growth factor receptor tyrosine kinase inhibitors: similar but different?

Two small-molecule epidermal growth factor receptor tyrosine kinase inhibitors, gefitinib and erlotinib, have been approved for the treatment of non-small-cell lung cancer. Here, we compare the pharmacology and pharmacokinetics of these agents, and reflect on how these properties may affect important clinical questions including the clinical efficacy, optimum dose, and whether there is a relationship between skin rash and clinical outcome for each of these agents. Gefitinib and erlotinib have similar mechanisms of action and pharmacological profiles; however, different molecular structures confer pharmacokinetic differences that may have important clinical implications. Although gefitinib 250 mg/day produces lower mean plasma concentrations and area under the plasma concentration versus time curve compared with erlotinib 150 mg/day, published data suggest that gefitinib significantly accumulates in tumour tissue. This difference may partly explain why it seems possible to achieve maximum clinical efficacy with gefitinib at doses significantly lower than its maximum tolerated dose and, hence, use of an optimal biological dose approach with this agent. We hypothesize that gefitinib is used and is effective at a dose below the maximum tolerated dose as it accumulates in tumour tissue, thus providing the concentration needed at its target to achieve effective epidermal growth factor receptor inhibition in the tumour while causing less skin toxicity than erlotinib; therefore, skin rash is not a useful predictive factor for efficacy with gefitinib.

Tumor response and health-related quality of life in clinically selected patients from Asia with advanced non-small-cell lung cancer treated with first-line gefitinib: Post hoc analyses from the IPASS study

BACKGROUND In IPASS (NCT00322452), progression-free survival (PFS, primary endpoint) was significantly longer with first-line gefitinib versus carboplatin/paclitaxel in never/light ex-smokers with advanced pulmonary adenocarcinoma in Asia, both in the overall intent-to-treat (ITT) population and in the EGFR mutation-positive subgroup. To further characterize the clinical relevance of these data, we investigated objective response rate (ORR) and health-related quality of life (HRQoL) in patients treated with gefitinib. METHODS Objective response was assessed (RECIST) 6-weekly (previously reported). Post hoc assessments included median time to response, median duration of response and change in tumor size. The analysis of response population included those patients treated with gefitinib who responded (n = 262 from ITT; n = 94 from EGFR mutation-positive subgroup). The percentage of patients with deterioration in HRQoL (Functional Assessment of Cancer Therapy-Lung [FACT-L], Trial Outcome Index [TOI]) and symptoms (Lung Cancer Subscale [LCS]) at 4 months post-randomization was analyzed according to progression status (EFQ population grouped by progressors/non-progressors in both treatment arms). The ORR (ITT) and incidence of skin rash/acne (evaluable-for-safety) were summarized. RESULTS In patients whose tumors responded to gefitinib, median time to response was 6.1 weeks in the ITT population (n = 262) and 6.0 weeks in the EGFR mutation-positive subgroup (n = 94); median duration of response was 9.7 and 8.7 months in these groups, respectively. There was significant tumor shrinkage with gefitinib. A greater percentage of patients in the EFQ population whose tumors progressed experienced deterioration in HRQoL and symptoms at 4 months versus patients whose tumors did not progress (FACT-L 33.7% vs 16.3%; TOI 33.7% vs 13.2%; LCS 31.7% vs 15.5%). In the gefitinib arm of the EFS population, incidence of rash was 75.8% and 68.1% in EGFR mutation-positive and -negative subgroups, respectively (with ORR for the gefitinib arm of the ITT 71.2% vs 1.1%, respectively). CONCLUSIONS Patients whose tumors responded to first-line gefitinib experienced significant tumor shrinkage and a rapid, durable response. Deterioration in HRQoL and lung cancer symptoms at 4 months post-randomization was found to be associated with tumor progression, highlighting the role of patient-reported outcomes in the evaluation of advanced NSCLC disease. Rash was not supported as a predictive marker of response to gefitinib.

Final analysis of overall survival for the Phase III CONFIRM trial: fulvestrant 500 mg versus 250 mg

Background: The COmparisoN of Faslodex In Recurrent or Metastatic breast cancer (CONFIRM) trial (NCT00099437) compared fulvestrant 500 mg with fulvestrant 250 mg in postmenopausal women with locally advanced or metastatic estrogen receptor (ER)-positive breast cancer who had recurred or progressed following prior endocrine therapy. Fulvestrant 500 mg was associated with a statistically significant increase in progression-free survival compared with fulvestrant 250 mg (Di Leo A et al. J Clin Oncol 2010; 28: 4594–4600). At the time of the primary analysis approximately 50% of patients had died. Median overall survival was 25.1 months and 22.8 months for fulvestrant 500 mg and 250 mg, respectively (hazard ratio [HR] 0.84; 95% confidence interval [CI] 0.69, 1.03; p = 0.091). A follow-up analysis of overall survival was subsequently planned for when 75% of patients had died and the results are presented here. Methods: CONFIRM was a randomized, double-blind, parallel-group, multicenter, Phase III study. Patients were randomized 1:1 to either fulvestrant 500 mg (500 mg i.m. on Days 0, 14 and 28 and every 28 days thereafter) or fulvestrant 250 mg (250 mg i.m. every 28 days). After the primary analysis, patients on fulvestrant 250 mg were permitted to switch to 500 mg and all patients were followed up for overall survival, regardless of treatment discontinuation, unless consent was withdrawn. Overall survival was analyzed using an unadjusted log-rank test. No adjustments were made for multiplicity. Serious adverse events (SAEs) were also reported. Results: In total, 736 women (median age 61.0 years) were randomized between February 2005 and August 2007 from 128 centers in 17 countries (fulvestrant 500 mg: n=362; fulvestrant 250 mg: n=374). At time of follow-up analysis, 63 (9.0%) patients were lost to follow-up, 16 (2.2%) patients had withdrawn consent, 103 (14.0%) patients were still ongoing (21 [2.9%] on treatment and 82 [11.1%] not on treatment), and 554 (75.3%) patients had died. Eight (2.1%) patients crossed over from fulvestrant 250 mg to 500 mg. Median overall survival was 26.4 months for fulvestrant 500 mg and 22.3 months for fulvestrant 250 mg (HR 0.81; 95% CI, 0.69, 0.96; nominal p = 0.016). During the treatment period, a total of 32 (8.9%) patients had at least one SAE in the fulvestrant 500 mg and 25 (6.7%) patients in the fulvestrant 250 mg groups, and SAEs that were causally related to study treatment were reported for 6 (1.7%) and 3 (0.8%) patients, respectively. SAEs with an outcome of death were reported for 5 (1.4%) and 6 (1.6%) patients, respectively, during the treatment period. Overall, there were no clinically important differences in the profiles of SAEs between the treatment groups and no clustering of SAEs could be detected in either treatment group. Conclusions: Overall survival data from CONFIRM demonstrate that, in patients with locally advanced or metastatic ER positive breast cancer, fulvestrant 500 mg is associated with a clinically relevant 4.1 month difference in median overall survival and 19% reduction in risk of death compared with fulvestrant 250 mg. There were no new safety concerns associated with the use of fulvestrant 500 mg. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr S1-4.

Gefitinib Plus Chemotherapy Versus Chemotherapy in Epidermal Growth Factor Receptor Mutation–Positive Non–Small-Cell Lung Cancer Resistant to First-Line Gefitinib (IMPRESS): Overall Survival and Biomarker Analyses

Purpose The Iressa Mutation-Positive Multicentre Treatment Beyond ProgRESsion Study (IMPRESS) compared the continuation of gefitinib plus chemotherapy with placebo plus chemotherapy in patients with epidermal growth factor receptor ( EGFR) mutation-positive advanced non-small-cell lung cancer with progression (Response Evaluation Criteria in Solid Tumors 1.1) after first-line gefitinib. Primary results indicated no difference between treatments in terms of progression-free survival (PFS). The current analysis presents final, mature, overall survival (OS) data, together with exploratory analyses that examined whether specific biomarkers, including T790M mutation status, were able to differentiate a relative treatment effect. Patients and Methods Patients were randomly assigned to gefitinib 250 mg or placebo, in addition to cisplatin 75 mg/m2 plus pemetrexed 500 mg/m2 (maximum of six cycles of chemotherapy). EGFR mutation status was determined from plasma-derived circulating free tumor-derived DNA samples (beads, emulsification, amplification, and magnetics digital polymerase chain reaction assay, allelic fraction analysis). Results A total of 265 patients with non-small-cell lung cancer were randomly assigned, and overall data maturity was 66%. Continuation of gefitinib plus cisplatin and pemetrexed was detrimental to OS when compared with placebo plus cisplatin and pemetrexed (hazard ratio [HR], 1.44; 95% CI, 1.07 to 1.94; P = .016; median OS, 13.4 v 19.5 months). The detriment was statistically significant in patients with T790M mutation-positive plasma samples (HR, 1.49; 95% CI, 1.02 to 2.21), whereas statistical significance was not reached in T790M mutation-negative patients (HR, 1.15; 95% CI, 0.68 to 1.94). PFS in T790M mutation-positive patients was similar between treatments, and the difference observed in T790M mutation-negative patients did not reach statistical significance (HR, 0.67; 95% CI, 0.43 to 1.03; P = .0745). Conclusion Final OS data from IMPRESS are supportive of earlier PFS results and are sufficient to warn physicians against the continuation of treatment with first-generation EGFR tyrosine kinase inhibitors beyond radiologic disease progression when chemotherapy is initiated. Plasma biomarker analyses suggest that this effect may be driven by T790M-positive status.

Abstract S6-04: Fulvestrant 500 mg versus anastrozole as first-line treatment for advanced breast cancer: Overall survival from the Phase II ‘FIRST’ study

Background: A clinically significant improvement in median overall survival (OS) has been reported for fulvestrant 500 mg vs fulvestrant 250 mg (26.4 months vs 22.3 months, respectively; hazard ratio [HR] 0.81; 95% confidence interval (CI) 0.69, 0.96; nominal p=0.02) in the Phase III COmparisoN of Faslodex In Recurrent or Metastatic breast cancer (CONFIRM) study, following failure on prior endocrine therapy. Therefore, further evidence for OS effects of fulvestrant 500 mg was sought. The Fulvestrant fIRst-line Study comparing endocrine Treatments (FIRST) compares fulvestrant 500 mg with anastrozole in the earlier first-line treatment setting for postmenopausal women with hormone receptor-positive (HR+) advanced breast cancer. In the primary analysis (6 months after last patient was randomized) fulvestrant 500 mg was at least as effective as anastrozole for clinical benefit rate (primary endpoint) and showed a significantly longer time to progression (TTP; median TTP not reached for fulvestrant 500 mg vs 12.5 months for anastrozole; HR 0.63; 95% CI 0.39, 1.00; p=0.05). In a follow-up analysis when 79.5% of patients (pts) had discontinued study treatment, median TTP was 23.4 months for fulvestrant 500 mg vs 13.1 months for anastrozole (HR 0.66; 95% CI 0.47, 0.92; p=0.01). Here we report OS from FIRST. Methods: FIRST is a Phase II, randomized, open-label, multicenter study (NCT00274469) comparing fulvestrant 500 mg (500 mg im on Days 0, 14 and 28, and every 28 days thereafter) with anastrozole (1 mg/day po). Pts were postmenopausal women with locally advanced or metastatic HR+ breast cancer who had not received prior endocrine therapy for locally advanced or metastatic disease. Kaplan-Meier curves of OS (time from randomization to death from any cause) will be compared by unadjusted log-rank test. Pts not known to have died including those lost to follow-up or with no survival information will be right-censored at last known date alive. Serious adverse events will also be reported. Results: In total, 205 pts (median age 67.0 years) were randomized from 62 centers in 9 countries (fulvestrant 500 mg: n=102; anastrozole: n=103). The first pt enrolled on Feb 6, 2006. As of May 14, 2014, 40/205 pts (19.5%) were alive across both treatment groups. 4 pts (2.0%) were lost to follow-up, 130 pts (63.4%) had died, and 31 pts [15.1%] did not participate in the OS follow-up (20 pts due to non-participation of center in the OS follow-up; other reasons included withdrawal of consent). A total of 130 events had occurred; preliminary data indicate a median OS of 50 months in the total study population. Data cut-off is planned for when approximately 65% pts have died, expected in Aug 2014. Comparative data between fulvestrant 500 mg and anastrozole for OS will be presented. Conclusions: We understand FIRST to be the only study that has demonstrated improved efficacy (ie TTP) for an alternative hormone therapy over a third-generation aromatase inhibitor for treatment of HR+ advanced breast cancer. Improved OS results would provide additional support for superior efficacy of fulvestrant 500 mg over anastrozole as first-line endocrine therapy for postmenopausal women with HR+ locally advanced or metastatic breast cancer. Citation Format: John FR Robertson, Antonio Llombart-Cussac, David Feltl, John Dewar, Marek Jasiowka, Nicola Hewson, Yuri Rukazenkov, Matthew J Ellis. Fulvestrant 500 mg versus anastrozole as first-line treatment for advanced breast cancer: Overall survival from the Phase II ‘FIRST’ study [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr S6-04.