Clinical Pharmacology for Tagrisso
Mechanism Of Action
Osimertinib is a kinase inhibitor of the epidermal growth factor receptor (EGFR), which binds irreversibly to certain mutant forms of EGFR (T790M, L858R, and exon 19 deletions) at approximately 9-fold lower concentrations than wild-type. Two pharmacologically-active metabolites (AZ7550 and AZ5104 circulating at approximately 10% of the parent) with similar inhibitory profiles to osimertinib have been identified in the plasma after oral administration of osimertinib. AZ7550 showed a similar potency to osimertinib, while AZ5104 showed greater potency against exon 19 deletion and T790M mutants (approximately 8-fold) and wild-type (approximately 15-fold) EGFR. In vitro, osimertinib also inhibited the activity of HER2, HER3, HER4, ACK1, and BLK at clinically relevant concentrations.
In cultured cells and animal tumor implantation models, osimertinib exhibited anti-tumor activity against NSCLC lines harboring EGFR-mutations (T790M/L858R, L858R, T790M/exon 19 deletion, and exon 19 deletion) and, to a lesser extent, wild-type EGFR amplifications. Osimertinib distributed to the brain in multiple animal species (monkey, rat, and mouse) with brain to plasma AUC ratios of approximately 2 following oral dosing. These data are consistent with observations of tumor regression and increased survival in osimertinib- versus control-treated animals in a pre-clinical mutant-EGFR intracranial mouse metastasis xenograft model (PC9; exon 19 deletion).
Pharmacodynamics
Based on an analysis of dose-exposure response relationships over the dose range of 20 mg (0.25 times the recommended dose) to 240 mg (3 times the recommended dose), no apparent relationship between osimertinib exposure and overall response rate, duration of response and progression-free survival was identified; however, there were limited data available at the 20 mg dose. Over the same dose range, increased exposure led to increased probability of adverse reactions, specifically rash, diarrhea and ILD.
Cardiac Electrophysiology
The QTc interval prolongation potential of osimertinib was assessed in 210 patients who received TAGRISSO 80 mg daily in AURA2. A central tendency analysis of the QTcF data at steady-state demonstrated that the maximum mean change from baseline was 16.2 msec (upper bound of two-sided 90% confidence interval (CI) 17.6 msec). A pharmacokinetic/pharmacodynamic analysis in AURA2 suggested a concentration-dependent QTc interval prolongation of 14 msec (upper bound of two-sided 90% CI: 16 msec) at a dose of TAGRISSO 80 mg.
Pharmacokinetics
The area under the plasma concentration-time curve (AUC) and maximal plasma concentration (Cmax) of osimertinib increased dose proportionally over 20 to 240 mg dose range (i.e., 0.25 to 3 times the recommended dosage) after oral administration and exhibited linear pharmacokinetics (PK). Administration of TAGRISSO orally once daily resulted in approximately 3-fold accumulation with steady-state exposures achieved after 15 days of dosing. At steady state, the Cmax to Cmin (minimal concentration) ratio was 1.6-fold.
The pharmacokinetics in patients treated with osimertinib in combination with pemetrexed and platinumbased chemotherapy are similar to those in patients treated with osimertinib monotherapy.
Absorption
The median time to Cmax of osimertinib was 6 hours (range 3-24 hours).
Following administration of a 20 mg TAGRISSO tablet with a high-fat, high-calorie meal (containing approximately 58 grams of fat and 1000 calories), the Cmax and AUC of osimertinib were comparable to that under fasting conditions.
Distribution
The mean volume of distribution at steady-state (Vss/F) of osimertinib was 918 L. Plasma protein binding of osimertinib was 95%. PET brain imaging studies in healthy volunteers and in patients with brain metastases show that osimertinib is distributed to the brain following intravenous injection of a micro dose of 11C-labeled osimertinib.
Elimination
Osimertinib plasma concentrations decreased with time and a population estimated mean half-life of osimertinib was 48 hours, and oral clearance (CL/F) was 14.3 (L/h).
Metabolism
The main metabolic pathways of osimertinib were oxidation (predominantly CYP3A) and dealkylation in vitro. Two pharmacologically active metabolites (AZ7550 and AZ5104) have been identified in the plasma after TAGRISSO oral administration. The geometric mean exposure (AUC) of each metabolite (AZ5104 and AZ7550) was approximately 10% of the exposure of osimertinib at steady-state.
Excretion
Osimertinib is primarily eliminated in the feces (68%) and to a lesser extent in the urine (14%). Unchanged osimertinib accounted for approximately 2% of the elimination.
Specific Populations
No clinically significant differences in the pharmacokinetics of osimertinib were observed based on age, sex, ethnicity, body weight, baseline albumin, line of therapy, smoking status, renal function (creatinine clearance (CLcr) ≥15 mL/min by Cockcroft-Gault), or hepatic impairment (Child-Pugh A and B, or total bilirubin ≤ ULN and AST > ULN or total bilirubin between 1 to 3 times ULN and any AST). The pharmacokinetics of osimertinib in patients with end-stage renal disease (CLcr <15 mL/min) or severe hepatic impairment (total bilirubin 3 to 10 times ULN and any AST) are unknown [see Use In Specific Populations].
Drug Interaction Studies
Effect Of Other Drugs On TAGRISSO In Clinical Pharmacokinetic Studies Strong CYP3A Inducers
The steady-state AUC of osimertinib was reduced by 78% in patients when co-administered with rifampin (600 mg daily for 21 days) [see DRUG INTERACTIONS ]. Strong CYP3A Inhibitors: Co-administering TAGRISSO with 200 mg itraconazole twice daily (a strong CYP3A4 inhibitor) had no clinically significant effect on the exposure of osimertinib (AUC increased by 24% and Cmax decreased by 20%).
Gastric Acid Reducing Agents
The exposure of osimertinib was not affected by concurrent administration of a single 80 mg TAGRISSO tablet following 40 mg omeprazole administration for 5 days.
Effect Of Osimertinib On Other Drugs In Clinical Pharmacokinetic Studies
BCRP substrates: Co-administering TAGRISSO with rosuvastatin (a BCRP substrate) increased rosuvastatin AUC by 35% and Cmax by 72% [see DRUG INTERACTIONS].
P-gp Substrates
Co-administering TAGRISSO with fexofenadine (a P-gp substrate) increased fexofenadine AUC and Cmax by 56% and 76% after a single dose and 27% and 25% at steady state, respectively.
CYP3A4 Substrates
Co-administering TAGRISSO with simvastatin (a CYP3A4 substrate) had no clinically significant effect on the exposure of simvastatin.
In Vitro Studies
CYP450 Metabolic Pathways
Osimertinib does not inhibit CYP1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6 and 2E1. Osimertinib induced CYP1A2 enzymes.
Transporter Systems
Osimertinib is a substrate of P-glycoprotein and BCRP and is not a substrate of OATP1B1 and OATP1B3. Osimertinib is an inhibitor of BCRP and does not inhibit OAT1, OAT3, OATP1B1, OATP1B3, MATE1, MATE2K and OCT2.
Animal Toxicology And/Or Pharmacology
Administration of osimertinib resulted in histological findings of lens fiber degeneration in the 2-year rat carcinogenicity study at ≥3 mg/kg/day (exposures 0.2 times the human exposure based on AUC). These findings were consistent with the ophthalmoscopic observation of lens opacities, which were first noted from week 52 and showed a gradual increase in incidence and severity with increased duration of dosing.
Clinical Studies
Adjuvant Treatment Of Early-Stage EGFR Mutation-Positive Non-Small Cell Lung Cancer (NSCLC)
The efficacy of TAGRISSO was demonstrated in a randomized, double-blind, placebo-controlled trial (ADAURA [NCT02511106]) for the adjuvant treatment of patients with EGFR exon 19 deletions or exon 21 L858R mutation-positive NSCLC who had complete tumor resection, with or without prior adjuvant chemotherapy. Eligible patients with resectable tumors (stage IB – IIIA according to American Joint Commission on Cancer [AJCC] 7th edition) were required to have predominantly non-squamous histology and EGFR exon 19 deletions or exon 21 L858R mutations identified prospectively from tumor tissue in a central laboratory by the cobas® EGFR Mutation Test. Patients with clinically significant uncontrolled cardiac disease, prior history of ILD/pneumonitis, or who received treatment with any EGFR kinase inhibitor were not eligible for the study.
Patients were randomized (1:1) to receive TAGRISSO 80 mg orally once daily or placebo following recovery from surgery and standard adjuvant chemotherapy if given. Patients who did not receive adjuvant chemotherapy were randomized within 10 weeks and patients who received adjuvant chemotherapy were randomized within 26 weeks following surgery. Randomization was stratified by mutation type (exon 19 deletions or exon 21 L858R mutations), race (Asian or other races) and pTNM staging (IB or II or IIIA) according to AJCC 7th edition. Treatment was given for 3 years or until disease recurrence, or unacceptable toxicity.
The major efficacy outcome measure was disease-free survival (DFS, defined as reduction in the risk of disease recurrence or death) in patients with stage II – IIIA NSCLC determined by investigator assessment. Additional efficacy outcome measures included DFS in the overall population (patients with stage IB – IIIA NSCLC), and overall survival (OS) in patients with stage II – IIIA NSCLC and in the overall population.
A total of 682 patients were randomized to TAGRISSO (n=339) or placebo (n=343). The median age was 63 years (range 30-86 years); 70% were female; 64% were Asian and 72% were never smokers. Baseline World Health Organization (WHO) performance status was 0 (64%) or 1 (36%); 31% had stage IB, 35% II, and 34% IIIA. With regard to EGFR mutation status, 55% were exon 19 deletions and 45% were exon 21 L858R mutations. The majority (60%) of patients received adjuvant chemotherapy prior to randomization (27% IB; 70% II, 79% IIIA).
ADAURA demonstrated a statistically significant difference in DFS for patients treated with TAGRISSO compared to patients treated with placebo. The final analysis of OS demonstrated a statistically significant improvement in OS for patients treated with TAGRISSO compared to patients treated with placebo. Median OS was not reached in either arm. In the overall population (IB-IIIA), the median follow-up time was 61.5 months in both treatment arms. Efficacy results from ADAURA are summarized in Table 14 and Figures 1 and 2, respectively.
Table 14: Efficacy Results in ADAURA according to Investigator Assessment
| Efficacy Parameter |
STAGE II-IIIA POPULATION |
STAGE IB-IIIA POPULATION |
TAGRISSO
(N=233) |
PLACEBO
(N=237) |
TAGRISSO
(N=339) |
PLACEBO
(N=343) |
| Disease-Free Survival (DFS) |
| DFS events (%) |
26 (11) |
130 (55) |
37 (11) |
159 (46) |
| Recurrent disease (%) |
26 (11) |
129 (54) |
37 (11) |
157 (46) |
| Deaths (%) |
0 |
1 (0.4) |
0 |
2 (0.6) |
| Median DFS, months (95% CI) |
NR (38.8, NE) |
19.6 (16.6, 24.5) |
NR (NE, NE) |
27.5 (22.0, 35.0) |
| Hazard ratio (95% CI)‡,§ |
0.17 (0. |
[2, 0.23) |
0.20 (0. |
[5, 0.27) |
| p-value‡,|| |
<0.0001 |
<0.0001 |
| Overall Survival (OS) |
| Number of deaths (%) |
35 (15) |
65 (27) |
42 (12) |
82 (24) |
| Hazard Ratio (95% CI)‡,§ |
0.49 (0.33, 0.73) |
0.49 (0.34, 0.70) |
| p-value‡,|| |
0.0004 |
<0.0001 |
DFS results based on investigator assessment.
CI=Confidence Interval; NE=Not Estimable; NR=Not Reached
‡Stratified by race (Asian vs other races), mutation status (Ex19del vs L858R), and pTNM staging.
§Pike estimator.
||Stratified log-rank test. |
Figure 1: Kaplan-Meier Curves of Disease-Free Survival (Overall Population) by Investigator Assessment in ADAURA
Figure 2: Kaplan-Meier Curves of Overall Survival (Overall Population) in ADAURA
In an exploratory analysis of site(s) of relapse, the proportion of patients with CNS involvement at the time of disease recurrence was 5 patients (1.5%) on the TAGRISSO arm and 34 patients (10%) on the placebo arm.
Locally Advanced, Unresectable (Stage III) EGFR Mutation Positive NSCLC
The efficacy of TAGRISSO was evaluated in the LAURA trial [NCT03521154], a double blind, randomized, placebo-controlled study in adult patients with locally advanced, unresectable stage III NSCLC with EGFR exon 19 deletions or exon 21 L858R mutations whose disease had not progressed during or following definitive platinum-based chemoradiation therapy. Eligible patients were randomized within 42 days prior to study randomization and had a WHO performance status of 0 or 1. Prior to study enrollment, patients received concurrent chemoradiation therapy (cCRT) or sequential chemoradiation therapy (sCRT) regimens, where at least 2 cycles every 3 weeks or 5 doses of weekly platinum-based chemotherapy and definitive radiation were to be completed ≤6 weeks prior to randomization. The study excluded patients who had progressive disease during or following definitive chemoradiation therapy and patients with Grade ≥2 pneumonitis after chemoradiation therapy or any ILD prior to chemoradiation therapy. Patient tumor tissue samples were required to have an EGFR exon 19 deletion or exon 21 L858R mutation, as identified by the cobas® EGFR Mutation Test v2 in a central laboratory or by an FDAapproved test at a CLIA certified- or accredited laboratory.
Patients were randomized (2:1) to receive either TAGRISSO 80 mg orally once daily or placebo until disease progression or unacceptable toxicity. Randomization was stratified by prior chemoradiation strategy (cCRT vs sCRT), tumor staging prior to chemoradiation (IIIA vs IIIB/IIIC), and by region (China versus rest of the world). Post progression, all patients were offered open label TAGRISSO if, in the opinion of the treating healthcare provider, there was an expected clinical benefit. Tumor assessments were performed every 8 weeks until week 48, and then every 12 weeks.
The major efficacy outcome measure was progression free survival (PFS) as assessed by blinded independent central review (BICR). Additional efficacy outcome measures included OS and CNS PFS.
A total of 216 patients were randomized (2:1) to TAGRISSO (n=143) or placebo (n=73). The study population characteristics were: median age 63 years (range 36-84 years); 13% ≥75 years old; 61% female; 82% Asian, 14% White, 1.4% American Indian or Alaska Native and 2.3% had reported race as other; 6% were Hispanic or Latino; and 70% were never smokers. Baseline WHO performance status was 0 (51%) or 1 (49%); 35% of patients had stage IIIA, 49% of patients had stage IIIB and 16% of patients had stage IIIC NSCLC; 4% had squamous and 96% had non-squamous histology; 54% had exon 19 deletions and 45% had exon 21 L858R mutations. Prior to randomization, 89% of patients received cCRT and 11% of patients received sCRT. All patients received platinum-based chemotherapy (55% carboplatin-based chemotherapy and 44% cisplatin-based chemotherapy). The median total dose of radiation was 60 Gy for patients in both arms.
LAURA demonstrated a statistically significant improvement in PFS for patients randomized to TAGRISSO as compared to placebo. Efficacy results from LAURA are summarized in Table 15, and the Kaplan-Meier curve for PFS is shown in Figure 3. While OS results were immature at the current analysis, with 36% of pre-specified deaths for the final analysis reported, no trend towards a detriment was observed.
Table 15: Efficacy Results in LAURA
| Efficacy Parameter |
TAGRISSO
(N=143) |
Placebo
(N=73) |
| Progression-Free Survival |
| PFS events (%) |
57 (40) |
63 (86) |
| Progressive disease (%) |
53 (37) |
62 (85) |
| Death* (%) |
4 (3) |
1 (1) |
| Median PFS in months (95% CI) |
39.1 (31.5, NE) |
5.6 (3.7, 7.4) |
| Hazard Ratio (95% CI)†,‡ |
0.16 (0.10, 0.24) |
| p-value†,§ |
<0.001 |
| Overall Response Rate¶ |
| ORR, % (95% CI) |
54 (45, 62) |
26 (17, 38) |
CI=Confidence Interval, NE=Not Estimable
PFS and ORR results as assessed by BICR.
*Without documented radiological disease progression.
†Stratified by disease stage prior to chemotherapy (IIIA vs IIIB/IIIC).
‡Pike estimator.
§Stratified log-rank test.
¶Confirmed responses. |
Figure 3: Kaplan-Meier Curves of PFS as assessed by BICR in LAURA
All patients underwent magnetic resonance imaging (MRI) brain scans at baseline and at each follow-up during the study. In an exploratory analysis of site(s) of relapse, the proportion of patients with new CNS lesions at the time of disease progression was 17/143 patients (12%) on the TAGRISSO arm and 26/73 patients (36%) on the placebo arm.
Previously Untreated EGFR Mutation-Positive Metastatic NSCLC
FLAURA – TAGRISSO Monotherapy
The efficacy of TAGRISSO was demonstrated in a randomized, multicenter, double-blind, activecontrolled trial (FLAURA [NCT02296125]) in patients with EGFR exon 19 deletions or exon 21 L858R mutation-positive, metastatic NSCLC, who had not received previous systemic treatment for metastatic disease. Patients were required to have measurable disease per RECIST v1.1, a WHO performance status of 0-1, and EGFR exon 19 deletions or exon 21 L858R mutation in tumor prospectively identified by the cobas® EGFR Mutation Test in a central laboratory or by an investigational assay at a CLIA-certified or accredited laboratory. Patients with CNS metastases not requiring steroids and with stable neurologic status for at least two weeks after completion of definitive surgery or radiotherapy were eligible. Patients were assessed at the investigator’s discretion for CNS metastases if they had a history of, or suspected, CNS metastases at study entry.
Patients were randomized (1:1) to receive TAGRISSO 80 mg orally once daily or to receive gefitinib 250 mg orally once daily or erlotinib 150 mg orally once daily until disease progression or unacceptable toxicity. Randomization was stratified by EGFR mutation type (exon 19 deletions or exon 21 L858R mutation) and ethnicity (Asian or Other races). Patients randomized to the control arm were offered TAGRISSO at the time of disease progression if tumor samples tested positive for the EGFR T790M mutation. The major efficacy outcome measure was progression-free survival (PFS), as assessed by investigator. Additional efficacy outcome measures included OS and overall response rate (ORR).
A total of 556 patients were randomized to TAGRISSO (n=279) or to control (gefitinib n=183; erlotinib n=94). The median age was 64 years (range 26-93 years); 54% were <65 years of age; 63% were female; 62% were Asian and 64% were never smokers. Baseline WHO performance status was 0 (41%) or 1 (59%); 5% had Stage IIIb and 95% had Stage IV; and 7% received prior systemic cytotoxic chemotherapy as neoadjuvant or adjuvant therapy. With regard to EGFR tumor testing, 63% were exon 19 deletions and 37% were exon 21 L858R; 5 patients (<1%) also had a concomitant de novo T790M mutation. EGFR mutation status was confirmed centrally using the cobas® EGFR Mutation Test in 90% of patients. At the time of the final data cut-off, of those randomized to TAGRISSO and to investigator’s choice erlotinib or gefitinib arm, 133 (48%) and 180 (65%) patients had received at least one subsequent treatment, respectively. Out of the 180 patients randomized to erlotinib or gefitinib who received subsequent treatment, 85 (47%) patients received TAGRISSO as first subsequent therapy.
FLAURA demonstrated a statistically significant improvement in PFS for patients randomized to TAGRISSO as compared to erlotinib or gefitinib (see Table 16 and Figure 4). The final analysis of overall survival demonstrated a statistically significant improvement in overall survival in patients randomized to TAGRISSO compared to erlotinib or gefitinib (see Table 17 and Figure 5).
Table 16: Efficacy Results in FLAURA according to Investigator Assessment
| Efficacy Parameter |
TAGRISSO
(N=279) |
EGFR TKI (gefitinib or erlotinib)
(N=277) |
| Progression-Free Survival (PFS) |
| PFS events (%) |
136 (49) |
206 (74) |
| Progressive disease (%) |
125 (45) |
192 (69) |
| Death* (%) |
11 (4) |
14 (5) |
| Median PFS in months (95% CI) |
18.9 (15.2, 21.4) |
10.2 (9.6, 11.1) |
| Hazard Ratio (95% CI)†, ‡ |
0.46 (0.37, 0.57) |
| p-value†, § |
<0.0001 |
| Overall Survival (OS) |
| Number of deaths (%) |
155 (56) |
166 (60) |
| Median OS in months (95% CI) |
38.6 (34.5, 41.8) |
31.8 (26.6, 36.0) |
| Hazard Ratio (95% CI)†, ‡ |
0.80 (0.64, 1.00) |
| p-value†, § |
0.0462 |
| Overall Response Rate (ORR)1 |
| ORR, % (95% CI)† |
77 (71, 82) |
69 (63, 74) |
| Complete response, % |
2 |
1 |
| Partial response, % |
75 |
68 |
| Duration of Response (DoR)¶ |
| Median in months (95% CI) |
17.6 (13.8, 22.0) |
9.6 (8.3, 11.1) |
*Without documented radiological disease progression.
†Stratified by ethnicity (Asian vs Other races) and mutation status (Ex19del vs L858R).
‡Pike estimator.
§Stratified log-rank test.
¶Confirmed responses. |
Figure 4: Kaplan-Meier Curves of PFS by Investigator Assessment in FLAURA
In a supportive analysis of PFS according to blinded independent central review (BICR), median PFS was 17.7 months in the TAGRISSO arm compared to 9.7 months in the EGFR TKI comparator arm (HR=0.45; 95% CI: 0.36, 0.57).
Figure 5: Kaplan-Meier Curves of Overall Survival in FLAURA
Of 556 patients, 200 patients (36%) had baseline brain scans reviewed by BICR; this included 106 patients in the TAGRISSO arm and 94 patients in the investigator choice of EGFR TKI arm. Of these 200 patients, 41 had measurable CNS lesions per RECIST v1.1. Results of pre-specified exploratory analyses of CNS ORR and duration of response (DoR) by BICR in the subset of patients with measurable CNS lesions at baseline are summarized in Table 17.
Table 17: CNS ORR and DOR by BICR in Patients with Measurable CNS Lesions at Baseline in FLAURA
|
TAGRISSO
N=22 |
EGFR TKI (gefitinib or erlotinib)
N=19 |
| CNS Tumor Response Assessment*,† |
| CNS ORR, % (95% CI) |
77 (55, 92) |
63 (38, 84) |
| Complete response, % |
18 |
0 |
| CNS Duration of Response‡ |
| Number of responders |
17 |
12 |
| Response Duration ≥6 months, % |
88 |
50 |
| Response Duration ≥12 months, % |
47 |
33 |
*According to RECIST v1.1.
†Based on confirmed response.
‡Based on patients with response only; DoR defined as the time from the date of first documented response (complete response or partial response) until progression or death event. |
Previously Untreated EGFR Mutation-Positive Locally Advanced Or Metastatic NSCLC
FLAURA2 – TAGRISSO in Combination with Pemetrexed and Platinum-based Chemotherapy
The efficacy of TAGRISSO in combination with pemetrexed and platinum-based chemotherapy was demonstrated in a randomized, multicenter, open-label trial (FLAURA2 [NCT04035486]) in patients with EGFR exon 19 deletion or exon 21 L858R mutation-positive locally advanced or metastatic NSCLC, who had not received previous systemic treatment for advanced disease. Patients were required to have measurable disease per RECIST v1.1, a WHO performance status of 0-1, and EGFR exon 19 deletions or exon 21 L858R mutations as identified by the cobas® EGFR Mutation Test v2 performed prospectively in tissue samples in a central laboratory or by a local test performed in a CLIA-certified or accredited laboratory.
Patients were randomized (1:1) to one of the following treatment arms:
- TAGRISSO (80 mg) orally once daily with pemetrexed (500 mg/m²) and investigator’s choice of cisplatin (75 mg/m²) or carboplatin (AUC5) administered intravenously on Day 1 of 21-day cycles for 4 cycles, followed by TAGRISSO (80 mg) orally once daily and pemetrexed (500 mg/m²) administered intravenously every 3 weeks
- TAGRISSO (80 mg) orally once daily
Randomization was stratified by race (Chinese/Asian, Other races except-Chinese/Asian or other races), WHO performance status (0 or 1), and method for tissue testing (central or local). Patients received study therapy until intolerance to therapy, or the investigator determined that the patient was no longer experiencing clinical benefit.
Progression-free survival, as assessed by investigator per RECIST 1.1 was the primary efficacy outcome measure. Overall survival was a key secondary outcome measure. Additional efficacy outcome measures included ORR and DoR.
A total of 557 patients were randomized to either TAGRISSO in combination with pemetrexed and platinum-based chemotherapy (n=279) or TAGRISSO monotherapy (n=278). The median age was 61 years (range 26-85 years); 39% were ≥65 years and 8% were ≥75 years of age; 61% were female; 64% were Asian and 66% were never smokers. Baseline WHO PS was 0 (37%) or 1 (63%); 4% had locally advanced and 96% had metastatic NSCLC; and 1.8% received prior systemic cytotoxic chemotherapy as neoadjuvant or adjuvant therapy. With regard to EGFR tumor testing, 61% of tumors had exon 19 deletions and 38% had exon 21 L858R mutations; 0.7% of patients had tumors with both exon 19 deletions and exon 21 L858R. EGFR mutation status was centrally confirmed using the cobas® EGFR Mutation Test v2 in 96% of patients.
FLAURA2 demonstrated a statistically significant improvement in PFS for patients randomized to TAGRISSO in combination with pemetrexed and platinum-based chemotherapy as compared to TAGRISSO monotherapy (see Table 18 and Figure 6). While OS results were immature at the current analysis, with 45% of pre-specified deaths for the final analysis reported, no trend towards a detriment was observed.
Table 18: Efficacy Results in FLAURA2 according to Investigator Assessment
| Efficacy Parameter |
TAGRISSO with pemetrexed and platinum-based chemotherapy
(N=279) |
TAGRISSO
(N=278) |
| Progression-Free Survival (PFS)# |
| PFS events (%) |
120 (43) |
166 (60) |
| Progressive disease (%) |
95 (34) |
158 (57) |
| Death* (%) |
25 (9) |
8 (2.9) |
| Median PFS in months (95% CI)t> |
25.5 (24.7, NE) |
16.7 (14.1, 21.3) |
| Hazard Ratio (95% CI)†,‡ |
0.62 (0.49, 0.79) |
| p-value†,§ |
<0.0001 |
| Overall Response Rate (ORR)¶,# |
| ORR, % (95% CI) |
77 (71, 82) |
69 (63, 74) |
| Complete response, % |
0.4 |
0.4 |
| Partial response, % |
76 |
68 |
| Duration of Response (DoR)¶ |
| Median in months (95% CI) |
24.9 (22.1, NE) |
17.9 (15.2, 20.9) |
NE=Not Estimable; NR=Not Reached
#PFS and ORR results by BICR were consistent with those reported via investigator assessment.
*Without documented radiological disease progression.
†Stratified by race (Chinese/Asian, -Other races except Chinese/Asian vs other races), WHO performance status (0 or 1) and method of tissue testing (central or local).
‡Pike estimator.
§Stratified log-rank test.
¶Confirmed responses. |
Figure 6: Kaplan-Meier Curves of PFS by Investigator Assessment in FLAURA2
All patients had available baseline brain scans reviewed by BICR using modified RECIST; 78/557 (14%) patients had CNS measurable lesions. Results of pre-specified exploratory analyses of CNS ORR and DoR by BICR are summarized in Table 19.
Table 19: Exploratory Analysis – CNS Efficacy by BICR in Patients with CNS Metastases on a Baseline Brain Scan in FLAURA2
| Efficacy Parameter |
TAGRISSO with pemetrexed and platinum-based chemotherapy
(N=40) |
TAGRISSO
(N=38) |
| CNS Tumor Response Assessment*,† |
| CNS ORR, % (95% CI) |
80 (64, 91) |
76 (60, 89) |
| Complete response, % |
48 |
16 |
| Partial response, % |
33 |
61 |
| CNS Duration of Response†,‡ |
| Number of responders |
32 |
29 |
| Response Duration ≥6 months, % |
75 |
50 |
| Response Duration ≥12 months, % |
65 |
34 |
*According to RECIST v1.1.
†Based on confirmed response.
‡Based on patients with response only; DoR defined as the time from the date of first documented response (complete response or partial response) until progression or death event. |
Previously Treated EGFR T790M Mutation-Positive Metastatic NSCLC
The efficacy of TAGRISSO was demonstrated in a randomized, multicenter open-label, active-controlled trial in patients with metastatic EGFR T790M mutation-positive NSCLC who had progressed on prior systemic therapy, including an EGFR TKI (AURA3) [NCT02151981]. All patients were required to have EGFR T790M mutation-positive NSCLC identified by the cobas® EGFR Mutation Test performed in a central laboratory prior to randomization.
A total of 419 patients were randomized 2:1 to receive TAGRISSO (n=279) or platinum-based doublet chemotherapy (n=140). Randomization was stratified by ethnicity (Asian vs other races). Patients in the TAGRISSO arm received TAGRISSO 80 mg orally once daily until intolerance to therapy, disease progression, or investigator determination that the patient was no longer benefiting from treatment. Patients in the chemotherapy arm received pemetrexed 500 mg/m² with carboplatin AUC5 or pemetrexed 500 mg/m² with cisplatin 75 mg/m² on Day 1 of every 21-day cycle for up to 6 cycles. Patients whose disease had not progressed after four cycles of platinum-based chemotherapy could have received pemetrexed maintenance therapy (pemetrexed 500 mg/m² on Day 1 of every 21-day cycle).
The major efficacy outcome measure was PFS according to Response Evaluation Criteria in Solid Tumors (RECIST v1.1) by investigator assessment. Additional efficacy outcome measures included ORR, DoR, and OS. Patients randomized to the chemotherapy arm who had radiological progression according to both investigator and BICR were permitted to cross-over to receive treatment with TAGRISSO.
The baseline demographic and disease characteristics of the overall trial population were: median age 62 years (range: 20-90 years), ≥75 years old (15%), female (64%), White (32%), Asian (65%), never smoker (68%), WHO performance status 0 or 1 (100%). Fifty-four percent (54%) of patients had extra-thoracic visceral metastases, including 34% with central nervous system (CNS) metastases (including 11% with measurable CNS metastases) and 23% with liver metastases. Forty-two percent (42%) of patients had metastatic bone disease.
In AURA3, there was a statistically significant improvement in PFS in the patients randomized to TAGRISSO compared to chemotherapy (see Table 20 and Figure 7). No statistically significant difference was observed between the treatment arms at final OS analysis. At the time of the final OS analysis, 99 patients (71%) randomized to chemotherapy had crossed over to TAGRISSO treatment.
Table 20: Efficacy Results According to Investigator Assessment in AURA3
| Efficacy Parameter |
TAGRISSO (N=279) |
Chemotherapy (N=140) |
| Progression-Free Survival |
| Number of events (%) |
140 (50) |
110 (79) |
| Progressive disease (%) |
129 (46) |
104 (74) |
| Death* (%) |
11 (4) |
6 (4) |
| Median PFS in months (95% CI) |
10.1 (8.3, 12.3) |
4.4 (4.2, 5.6) |
| Hazard Ratio (95% CI)†,‡ |
0.30 (0.23,0.41) |
| p-value†,§ |
<0.001 |
| Overall Survival |
| Number of deaths (%) |
188 (67) |
93 (66) |
| Median OS in months (95% CI) |
26.8 (23.5, 31.5) |
22.5 (20.2, 28.8) |
| Hazard Ratio (95% CI)†,‡ |
0.87 (0.67, 1.12) |
| p-value†,§ |
0.277 |
| Overall Response Rate¶ |
| ORR, % (95% CI) |
65 (59, 70) |
29 (21, 37) |
| Complete response, % |
1 |
1 |
| Partial response, % |
63 |
27 |
| p-value†,# |
<0.001 |
| Duration of Response (DoR) |
| Median in months (95% CI) |
11.0 (8.6, 12.6) |
4.2 (3.0, 5.9) |
*Without documented radiological disease progression.
†Stratified by ethnicity (Asian vs other races).
‡Pike estimator.
§Stratified log-rank test.
¶Confirmed responses.
#Logistic regression analysis. |
Figure 7: Kaplan-Meier Curves of PFS by Investigator Assessment in AURA3
In a supportive analysis of PFS according to BICR, median PFS was 11 months in the TAGRISSO arm compared to 4.2 months in the chemotherapy arm (HR 0.28; 95% CI: 0.20, 0.38).
Of 419 patients, 205 (49%) had baseline brain scans reviewed by BICR; this included 134 (48%) patients in the TAGRISSO arm and 71 (51%) patients in the chemotherapy arm. Assessment of CNS efficacy by RECIST v1.1 was performed in the subgroup of 46/419 (11%) patients identified by BICR to have measurable CNS lesions on a baseline brain scan. Results are summarized in Table 21.
Table 21: CNS ORR and DoR by BICR in Patients with Measurable CNS Lesions at Baseline in AURA3
|
TAGRISSO
N=30 |
Chemotherapy
N=16 |
| CNS Tumor Response Assessment*,† |
| CNS ORR, % (95% CI) |
57 (37, 75) |
25 (7, 52) |
| Complete response, % |
7 |
0 |
| Duration of CNS Response†,‡ |
| Number of responders |
17 |
4 |
| Response Duration ≥6 months, % |
47 |
0 |
| Response Duration ≥9 months, % |
12 |
0 |
*According to RECIST v1.1.
†Based on confirmed response.
‡Based on patients with response only; DoR defined as the time from the date of first documented response (complete response or partial response) until progression or death event. |