A Phase 1 Study to Evaluate Absolute Bioavailability and Absorption, Distribution, Metabolism, and Excretion of Savolitinib in Healthy Male Volunteers.

Savolitinib is an oral MET (hepatocyte growth factor receptor) tyrosine kinase inhibitor, with demonstrated preliminary efficacy in several cancer types. Previous pharmacokinetics assessments showed that savolitinib is rapidly absorbed but there are limited data on the absolute bioavailability and absorption, distribution, metabolism, and excretion (ADME) of savolitinib. This open-label, two-part, phase 1 clinical study (NCT04675021) used a radiolabeled micro-tracer approach to evaluate absolute bioavailability and a traditional approach to determine the ADME of savolitinib in healthy male adult volunteers (N = 8). Pharmacokinetics, safety, and metabolic profiling and structural identification from plasma, urine, and fecal samples were also assessed. Volunteers received a single oral savolitinib 600 mg dose followed by intravenous 100 µg of [14 C]savolitinib in Part 1 and a single oral 300 mg [14 C]savolitinib dose (≤4.1 MBq [megabecquerel] [14 C]) in Part 2. Following Part 1, absolute oral bioavailability was 69%, the median time of maximum observed concentration was 3.5 hours, and the mean terminal half-life was 6.1 hours. Following Part 2, 94% of the radioactivity administered was recovered, with 56% and 38% in urine and feces, respectively. Exposure to savolitinib and metabolites M8, M44, M2, and M3 accounted for 22%, 36%, 13%, 7%, and 2%, respectively, of plasma total radioactivity. Approximately 3% of the dose was excreted as unchanged savolitinib in urine. Most savolitinib elimination occurred via metabolism by several different pathways. No new safety signals were observed. Our data show that the oral bioavailability of savolitinib is high and the majority of savolitinib elimination occurs via metabolism and is excreted in the urine.

Osimertinib + Savolitinib to Overcome Acquired MET-Mediated Resistance in Epidermal Growth Factor Receptor-Mutated, MET-Amplified Non-Small Cell Lung Cancer: TATTON.

MET-inhibitor and EGFR tyrosine kinase inhibitor (EGFR-TKI) combination therapy could overcome acquired MET-mediated osimertinib resistance. We present the final phase Ib TATTON (NCT02143466) analysis (Part B, n = 138/Part D, n = 42) assessing oral savolitinib 600 mg/300 mg once daily (q.d.) + osimertinib 80 mg q.d. in patients with MET-amplified, EGFR-mutated (EGFRm) advanced non-small cell lung cancer (NSCLC) and progression on prior EGFR-TKI. An acceptable safety profile was observed. In Parts B and D, respectively, objective response rates were 33% to 67% and 62%, and median progression-free survival (PFS) was 5.5 to 11.1 months and 9.0 months. Increased antitumor activity may occur with MET copy number ≥10. EGFRm circulating tumor DNA clearance on treatment predicted longer PFS in patients with detectable baseline ctDNA, while acquired resistance mechanisms to osimertinib + savolitinib were mediated by MET, EGFR, or KRAS alterations. SIGNIFICANCE: The savolitinib + osimertinib combination represents a promising therapy in patients with MET-amplified/overexpressed, EGFRm advanced NSCLC with disease progression on a prior EGFR-TKI. Acquired resistance mechanisms to this combination include those via MET, EGFR, and KRAS. On-treatment ctDNA dynamics can predict clinical outcomes and may provide an opportunity to inform earlier decision-making. This article is highlighted in the In This Issue feature, p. 1.

Osimertinib plus Selumetinib in EGFR-Mutated Non-Small Cell Lung Cancer After Progression on EGFR-TKIs: A Phase Ib, Open-Label, Multicenter Trial (TATTON Part B).

BACKGROUND: MEK/ERK inhibition can overcome acquired resistance to osimertinib in preclinical models. Osimertinib [EGFR-tyrosine kinase inhibitor (TKI)] plus selumetinib (MEK1/2 inhibitor) was assessed in the global TATTON study. METHODS: This multicenter, open-label, phase Ib study expansion cohort enrolled patients (aged ≥18 years) with MET-negative, EGFRm advanced NSCLC who had progressed on EGFR-TKIs. Patients were assigned to one of two cohorts by prior first- or second-generation or T790M-directed EGFR-TKI and received osimertinib 80 mg every day and intermittent selumetinib 75 mg twice a day orally. Safety and tolerability (primary objective) and antitumor activity determined by objective response rate (ORR), and progression-free survival (PFS) using RECIST v1.1 were assessed. Data cutoff: March 4, 2020. RESULTS: Forty-seven patients received treatment (prior first- or second-generation EGFR-TKI, n = 12; prior T790M-directed EGFR-TKI, n = 35). Forty-four (94%) patients were Asian; 30 (64%) had baseline exon 19 deletion. Most common AEs were diarrhea (89%), decreased appetite (40%), and stomatitis (32%); 11/47 patients (23%) had an AE Grade ≥3 possibly causally selumetinib-related. ORR was 66.7% [95% confidence interval (CI), 34.9-90.1] in the prior first- or second-generation EGFR-TKI group, 22.9% (95% CI, 10.4-40.1) in the prior T790M-directed EGFR-TKI group, and 34.0% (95% CI, 20.9-49.3) overall; median PFS was 15.0 (95% CI, 2.7-33.0), 2.8 (95% CI, 1.6-5.5), and 4.2 months (95% CI, 2.7-7.2), respectively. CONCLUSIONS: In this small study, AEs and tolerability of osimertinib plus selumetinib were as expected, on the basis of previous studies. The combination demonstrated antitumor activity supportive of further investigation in patients with MET-negative, EGFRm advanced NSCLC who had progressed on a previous EGFR-TKI.

Osimertinib Plus Durvalumab in Patients With EGFR-Mutated, Advanced NSCLC: A Phase 1b, Open-Label, Multicenter Trial.

INTRODUCTION: EGFR tyrosine kinase inhibitors (TKIs) are recommended for EGFR-mutated NSCLC treatment. EGFR activation up-regulates programmed death-ligand 1 expression and other immunosuppressive factors in NSCLC, causing immune microenvironment remodeling. Osimertinib (an EGFR TKI) plus durvalumab (programmed death-ligand 1 blockade) was evaluated in the TATTON study (NCT02143466). METHODS: This open-label, phase 1b study enrolled patients with advanced EGFR-mutated NSCLC. In part A, patients who had progressed on a previous EGFR TKI received osimertinib (80 mg once daily) plus durvalumab 3 or 10 mg/kg every 2 weeks. In part B, patients received first-line osimertinib plus durvalumab 10 mg/kg every 2 weeks. However, part B enrollment was terminated early owing to an increased incidence of interstitial lung disease (ILD)-related adverse events (AEs). Safety (primary objective) and preliminary anti-tumor activity determined by objective response rate (ORR), best overall response, duration of response (DOR), and progression-free survival were evaluated. RESULTS: Before enrollment termination, 23 and 11 patients received treatment across parts A and B, respectively. The most common AEs across parts A and B were as follows: diarrhea (50%), nausea (41%), and decreased appetite (35%). A total of 12 patients (35%) reported ILD-related AEs (lung disorder, ILD or pneumonitis). In part A, ORR was 43% (95% confidence interval [CI]: 23-66); median DOR was 20.4 months. In part B, ORR was 82% (95% CI: 48-98), median DOR was 7.1 months, and median progression-free survival was 9.0 months (95% CI: 3.5-12.3). CONCLUSIONS: This study highlighted a potential risk of ILD-related AEs when combining osimertinib with durvalumab. Further research looking to combine EGFR TKIs with immune checkpoint inhibitors should be approached with caution.

Osimertinib plus savolitinib in patients with EGFR mutation-positive, MET-amplified, non-small-cell lung cancer after progression on EGFR tyrosine kinase inhibitors: interim results from a multicentre, open-label, phase 1b study.

BACKGROUND: Preclinical data suggest that EGFR tyrosine kinase inhibitors (TKIs) plus MET TKIs are a possible treatment for EGFR mutation-positive lung cancers with MET-driven acquired resistance. Phase 1 safety data of savolitinib (also known as AZD6094, HMPL-504, volitinib), a potent, selective MET TKI, plus osimertinib, a third-generation EGFR TKI, have provided recommended doses for study. Here, we report the assessment of osimertinib plus savolitinib in two global expansion cohorts of the TATTON study. METHODS: In this multi-arm, multicentre, open-label, phase 1b study, we enrolled adult patients (aged ≥18 years) with locally advanced or metastatic, MET-amplified, EGFR mutation-positive non-small-cell lung cancer, who had progressed on EGFR TKIs. We considered two expansion cohorts: parts B and D. Part B consisted of three cohorts of patients: those who had been previously treated with a third-generation EGFR TKI (B1) and those who had not been previously treated with a third-generation EGFR TKI who were either Thr790Met negative (B2) or Thr790Met positive (B3). In part B, patients received oral osimertinib 80 mg and savolitinib 600 mg daily; after a protocol amendment (March 12, 2018), patients who weighed no more than 55 kg received a 300 mg dose of savolitinib. Part D enrolled patients who had not previously received a third-generation EGFR TKI and were Thr790Met negative; these patients received osimertinib 80 mg plus savolitinib 300 mg. Primary endpoints were safety and tolerability, which were assessed in all dosed patients. Secondary endpoints included the proportion of patients who had an objective response per RECIST 1.1 and was assessed in all dosed patients and all patients with centrally confirmed MET amplification. Here, we present an interim analysis with data cutoff on March 29, 2019. This study is registered with ClinicalTrials.gov, NCT02143466. FINDINGS: Between May 26, 2015, and Feb 14, 2019, we enrolled 144 patients into part B and 42 patients into part D. In part B, 138 patients received osimertinib plus savolitinib 600 mg (n=130) or 300 mg (n=8). In part D, 42 patients received osimertinib plus savolitinib 300 mg. 79 (57%) of 138 patients in part B and 16 (38%) of 42 patients in part D had adverse events of grade 3 or worse. 115 (83%) patients in part B and 25 (60%) patients in part D had adverse events possibly related to savolitinib and serious adverse events were reported in 62 (45%) patients in part B and 11 (26%) patients in part D; two adverse events leading to death (acute renal failure and death, cause unknown) were possibly related to treatment in part B. Objective partial responses were observed in 66 (48%; 95% CI 39-56) patients in part B and 23 (64%; 46-79) in part D. INTERPRETATION: The combination of osimertinib and savolitinib has acceptable risk-benefit profile and encouraging antitumour activity in patients with MET-amplified, EGFR mutation-positive, advanced NSCLC, who had disease progression on a previous EGFR TKI. This combination might be a potential treatment option for patients with MET-driven resistance to EGFR TKIs. FUNDING: AstraZeneca.

Impact of Disease and Treatment Response in Drug-Drug Interaction Studies: Osimertinib and Simvastatin in Advanced Non-Small Cell Lung Cancer.

A phase I, open-label study (NCT02197234) assessed the effects of osimertinib on simvastatin exposure in patients with advanced epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer and disease progression post-EGFR tyrosine kinase inhibitor treatment. Here, we report on a retrospective analysis of two patients (patients 1 and 2) who had liver metastases and high simvastatin exposure prior to osimertinib treatment, which changed following treatment. Patients received single oral doses of simvastatin 40 mg on day (D) 1 and D31, and osimertinib 80 mg once daily on D3-32. At baseline, both patients had abnormal liver function tests (LFTs; Child-Pugh scores of 6 and 8, respectively), significant liver metastasis, and, after a single simvastatin dose, had higher (~ 10-fold) exposure compared with all other patients. Following 31 days of continuous osimertinib treatment, simvastatin exposures (area under the plasma concentration-time curve from zero to infinity (AUC) and maximum plasma concentration (Cmax )) and LFTs, such as alanine transaminase, aspartate aminotransferase, and bilirubin normalized to population mean values. Additionally, ~ 50% and ~ 80% reductions in liver metastases were observed on computed tomography scans in patients 1 and 2, respectively. High simvastatin exposure on D1 likely resulted from impairment of hepatic first pass metabolism due to liver metastases. Reduction in hepatic disease burden due to osimertinib treatment likely resulted in liver function returning to normal levels.

Osimertinib in patients with T790M mutation-positive, advanced non-small cell lung cancer: Long-term follow-up from a pooled analysis of 2 phase 2 studies.

BACKGROUND: Osimertinib is a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) that is selective for both EGFR-TKI-sensitizing and T790M (threonine-to-methionine substitution at codon 790)-resistance mutations. The authors present long-term follow-up data from a preplanned, pooled analysis of phase 2 studies, the AZD9291 First Time in Patients Ascending Dose Study (AURA) extension trial (clincialtrials.gov identifier NCT01802632) and the AURA2 trial (NCT02094261). METHODS: Patients with centrally confirmed, T790M mutation-positive, advanced non-small cell lung cancer received osimertinib 80 mg once daily until disease progression or study discontinuation. Response was assessed by a blinded, independent, central review using Response Evaluation Criteria in Solid Tumors, version 1.1. The primary endpoint was the objective response rate. RESULTS: In total, 411 patients received osimertinib (second line, 129 patients; third line or later, 282 patients). At the data cutoff date of November 1, 2016, the median treatment exposure was 16.4 months (range, 0-29.7 months), the objective response rate was 66% (95% confidence interval [CI], 61%-70%), the median response duration was 12.3 months (95% CI, 11.1-13.8 months), and the median progression-free survival was 9.9 months (95% CI, 9.5-12.3 months). At the data cutoff date of May 1, 2018, 271 patients (66%) had died, and 140 patients (34%) had discontinued before death. The median overall survival was 26.8 months (95% CI, 24.0-29.1 months); and the 12-month, 24-month, and 36-month survival rates were 80%, 55%, and 37%, respectively. Grade ≥3 possibly causally related (investigator assessed) adverse events were reported in 65 patients (16%), and the most common were rash (grouped terms; 42%; grade ≥3, 1%) and diarrhea (39%; <1%). CONCLUSIONS: This pooled analysis represents the most mature clinical trial data for osimertinib in patients with pretreated, T790M-positive, advanced non-small cell lung cancer, further establishing osimertinib as a standard of care for this patient population.

Osimertinib in patients with epidermal growth factor receptor T790M advanced non-small cell lung cancer selected using cytology samples.

Osimertinib is a potent, irreversible epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) selective for EGFR-TKI sensitizing (EGFRm) and T790M resistance mutations. The primary objective of the cytology cohort in the AURA study was to investigate safety and efficacy of osimertinib in pretreated Japanese patients with EGFR T790M mutation-positive non-small cell lung cancer (NSCLC), with screening EGFR T790M mutation status determined from cytology samples. The cytology cohort was included in the Phase I dose expansion component of the AURA study. Patients were enrolled based on a positive result of T790M by using cytology samples, and received osimertinib 80 mg in tablet form once daily until disease progression or until clinical benefit was no longer observed at the discretion of the investigator. Primary endpoint for efficacy was objective response rate (ORR) by investigator assessment. Twenty-eight Japanese patients were enrolled into the cytology cohort. At data cut-off (February 1, 2016), 12 (43%) were on treatment. Investigator-assessed ORR was 75% (95% confidence interval [CI] 55, 89) and median duration of response was 9.7 months (95% CI 3.8, not calculable [NC]). Median progression-free survival was 8.3 months (95% CI 4.2, NC) and disease control rate was 96% (95% CI 82, 100). The most common all-causality adverse events were paronychia (46%), dry skin (46%), diarrhea (36%) and rash (36%). Osimertinib provided clinical benefit with a manageable safety profile in patients with pretreated EGFR T790M mutation-positive NSCLC whose screening EGFR T790M mutation-positive status was determined from cytology samples. (ClinicalTrials.gov number NCT01802632).

Pharmacokinetics of Osimertinib in Chinese Patients With Advanced NSCLC: A Phase 1 Study.

Osimertinib is an oral, irreversible, central nervous system active epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) selective for both EGFR-TKI sensitizing and T790M resistance mutations. The study's (NCT02529995) primary objective was to characterize the pharmacokinetics (PK) of osimertinib and its metabolites in Chinese patients enrolled in China. PK was assessed following single and multiple doses of 40 or 80 mg osimertinib once daily. Patients were aged ≥ 18 years with locally advanced or metastatic EGFR-TKI-sensitizing (EGFRm) non-small cell lung cancer and World Health Organization performance status of 0/1, who had progressed following prior EGFR-TKI. Thirty-one patients were assigned to treatment (40 mg, n = 15; 80 mg, n = 16), and 25 were included in the PK analyses set (40 mg, n = 12; 80 mg, n = 13). Six were excluded from analyses because of prior treatment with an osimertinib-like substance. At steady state a flat PK profile with a low maximum-minimum plasma concentration ratio was observed. Investigator-assessed objective response rate was 47% (7 of 15; 95%CI, 21.3-73.4) in the 40-mg cohort and 75% (12 of 16; 95%CI, 47.6-92.7) in the 80-mg cohort. Adverse events (AEs) leading to dose modification and treatment discontinuation were reported in 2 patients (6%) and 3 patients (10%), respectively. Serious AEs were reported in 8 patients (26%) and AEs leading to death in 1 patient (3%). Interstitial lung disease/pneumonitis-like event was reported in 1 patient (3%). Osimertinib PK in a Chinese patient population is well characterized and consistent with the global population, supporting the use of a once-daily 80-mg dose.

Comparison of the Pharmacokinetics of the Phase II and Phase III Capsule Formulations of Selumetinib and the Effects of Food on Exposure: Results From Two Randomized Crossover Trials in Healthy Male Subjects.

PURPOSE: Selumetinib (AZD6244, ARRY-142886), an oral, potent, and highly selective mitogen-activated protein kinase 1/2 inhibitor with a short half-life, has shown activity across various tumor types. Before initiation of Phase III trials, the site, scale, and color (hypromellose shell from white [Phase II] to blue [Phase III]) of the selumetinib 25mg capsule manufacture was changed. We present 2 crossover trials evaluating Phase III capsules in healthy subjects. METHODS: The relative bioavailability trial was a Phase I, open-label, randomized, 3-treatment, 4-period, 6-sequence crossover trial in healthy male subjects (aged 18-55 years). Subjects received selumetinib 75mg (3 × 25 mg) Phase II or Phase III capsules, or a 35mg oral solution, during 4 dosing periods in 1 of 6 randomized treatment sequences. The food effect trial was a Phase I, open-label, randomized, 2-period crossover trial in healthy male subjects (aged 18-45 years). Subjects were randomized to 1 of 2 sequences to receive selumetinib 75mg (3 × 25 mg) Phase III capsules. In sequence 1, subjects received selumetinib after 10 hours of fasting. Following a washout period, selumetinib was administered after a high-fat meal. In sequence 2, subjects received selumetinib in the fed state, before the fasted state. Pharmacokinetic parameters were determined from serial blood sampling. FINDINGS: Twenty-seven subjects were randomized to the relative bioavailability trial; 26 completed all dosing periods. Mean selumetinib AUC was unchanged (geometric least squares mean ratio [GLSMR], 90.01% [90% CI, 81.74-99.11]). Cmax was 18% lower with the Phase III capsules (GLSMR, 81.97% [90% CI, 69.01-97.36]). A post hoc exploratory statistical analysis excluding outlying observations with later Tmax showed that Phase II and III capsules produced similar exposure in terms of Cmax and AUC. High intrasubject variability for Cmax attributed to the pharmacokinetic sampling schedule was judged to have impacted on the estimated GLSMR. In the food effect trial, 34 subjects completed both study periods. A high-fat meal reduced selumetinib Cmax compared with the fasted state (GLSMR, 49.76% [90% CI, 43.82-56.51]); AUC was minimally changed (GLSMR, 84.08% [90% CI, 80.72-87.59]). Median Tmax was prolonged by 1.49 hours. No deaths or serious adverse events were reported. IMPLICATIONS: Selumetinib 75mg (3 × 25 mg) Phase III capsules are being used in ongoing pivotal Phase III trials and should be administered in the fasted state. Based on findings from the relative bioavailability trial, pharmacokinetic sampling frequency was increased for healthy subject trials, including the food effect trial. ClinicalTrials.gov identifiers: NCT01635023 (relative bioavailability) and NCT01974349 (food effect).

Modulation of Biomarker Expression by Osimertinib: Results of the Paired Tumor Biopsy Cohorts of the AURA Phase I Trial.

INTRODUCTION: Osimertinib is an oral, potent, irreversible EGFR tyrosine kinase inhibitor (TKI) selective for EGFR TKI and T790M resistance mutations. To enhance understanding of osimertinib's mechanism of action, we aimed to evaluate the modulation of key molecular biomarkers after osimertinib treatment in paired clinical samples from the phase I AURA trial. METHODS: Paired tumor biopsy samples were collected before the study and after 15 plus or minus 7 days of osimertinib treatment (80 or 160 mg daily). Clinical efficacy outcomes were assessed according to whether viable paired biopsy samples could be collected; safety was also assessed. Immunohistochemical analyses assessed key pathway and tumor/immune-relevant markers (phospho-EGFR, phospho-S6, phospho-AKT, programmed death ligand 1, and CD8), with samples scored by image analysis or a pathologist blinded to treatment allocation. RESULTS: Predose tumor biopsy samples were collected from 61 patients with EGFR T790M tumors; 29 patients had no viable postdose biopsy sample because of tumor regression or insufficient tumor sample. Evaluable predose and postdose tumor biopsy samples were collected from 24 patients. Objective response rate (ORR) and median progression-free survival (mPFS) were improved in patients from whom a postdose biopsy sample could not be collected (ORR 62% and mPFS 9.7 months [p = 0.027]) compared with those from whom paired samples were collected (ORR 29% and mPFS 6.6 months). Osimertinib modulated key EGFR signaling pathways and led to increased immune cell infiltration. CONCLUSIONS: Collection of paired biopsy samples was challenging because of rapid tumor regression after osimertinib treatment, highlighting the difficulties of performing on-study biopsies in patients treated with highly active drugs.

EGFR T790M mutation testing within the osimertinib AURA Phase I study.

OBJECTIVES: Reliable epidermal growth factor receptor (EGFR) mutation testing techniques are required to identify eligible patients with EGFR mutation/T790M positive advanced non-small cell lung cancer (NSCLC), for treatment with osimertinib (AZD9291), an oral, potent, irreversible EGFR tyrosine kinase inhibitor (TKI) selective for EGFR-TKI-sensitizing and T790M resistance mutations over wild-type EGFR. There is no current consensus regarding the best method to detect EGFR T790M mutations. The aim of this study was to describe the concordance between local testing, which used a variety of methods, and central testing, using the cobas® EGFR Mutation Test, for EGFR-sensitizing mutations and the T790M resistance mutation. MATERIALS AND METHODS: Tumor samples were obtained from all patients screened for inclusion onto the osimertinib Phase I expansion component of the AURA Phase I/II study (NCT01802632). Samples underwent central laboratory testing for EGFR-sensitizing mutations and T790M resistance mutation using the cobas® EGFR Mutation Test. Results were compared with local laboratory test results, based on other testing methodologies including Sanger sequencing, therascreen®, PNAClamp™, and Sequenom MassARRAY®. RESULTS: Central laboratory testing was successful in 99% of samples passing histopathology review and testing success rates were comparable across the three central laboratories. Concordance between central and local testing for common sensitizing mutations was high (>98%) and concordance for the T790M mutation was also high (>90%). Tumor heterogeneity, along with other technical factors may have influenced this result. CONCLUSIONS: Within the osimertinib AURA Phase I study, EGFR mutation testing across three centralized laboratories using the cobas® EGFR Mutation Test was feasible and successful, with strong concordance between local and central laboratory results, including for T790M. The cobas® EGFR Mutation Test has subsequently been approved as the companion diagnostic test for osimertinib in the USA and Japan.

EGFR Mutation Analysis for Prospective Patient Selection in Two Phase II Registration Studies of Osimertinib.

INTRODUCTION: Osimertinib is an oral, central nervous system-active, EGFR tyrosine kinase inhibitor (TKI) for the treatment of EGFR T790M-positive advanced NSCLC. Here we have evaluated EGFR mutation frequencies in two phase II studies of osimertinib (AURA extension and AURA2). METHODS: After progression while receiving their latest line of therapy, patients with EGFR mutation-positive advanced NSCLC provided tumor samples for mandatory central T790M testing for the study selection criteria. Tumor tissue mutation analysis for patient selection was performed with the Roche cobas EGFR Mutation Test (European Conformity-in vitro diagnostic, labeled investigational use only) (Roche Molecular Systems, Pleasanton, CA). Patients should not have been prescreened for T790M mutation status. The cobas test results were compared with those of the MiSeq next-generation sequencing system (Illumina, San Diego, CA), which was used as a reference method. RESULTS: Samples from 324 and 373 patients screened for AURA extension and AURA2, respectively, produced valid cobas test results. The T790M detection rates were similar between AURA extension and AURA2 (64% and 63%, respectively). The pooled T790M rate was 63%, with no difference by ethnicity (63% for Asian and non-Asian patients alike) or immediately prior treatment with an EGFR TKI (afatinib, 69%; erlotinib, 69%; and gefitinib, 63%). A higher proportion of patients had T790M detected against a background of exon 19 deletions versus L858R mutation (73% versus 58% [p = 0.0002]). In both trials the cobas test demonstrated high sensitivity (positive percent agreement) and specificity (negative percent agreement) for T790M detection when compared with the next-generation sequencing reference method: positive percent agreement of 91% versus 89% and negative percent agreement of 97% versus 98%. CONCLUSIONS: In both trials, the rate of detection of T790M mutation in patients with advanced NSCLC was approximately 63% and was unaffected by immediately prior treatment with an EGFR TKI or ethnicity.

Plasma ctDNA Analysis for Detection of the EGFR T790M Mutation in Patients with Advanced Non-Small Cell Lung Cancer.

INTRODUCTION: Tumor biopsies for detecting EGFR mutations in advanced NSCLC are invasive, costly, and not always feasible for patients with late-stage disease. The clinical utility of the cobas EGFR Mutation Test v2 (Roche Molecular Systems, Inc., Pleasanton, CA) with plasma samples from patients with NSCLC at disease progression after previous EGFR tyrosine kinase inhibitor therapy was investigated to determine eligibility for osimertinib treatment. METHODS: Matched tumor tissue and plasma samples from patients screened for the AURA extension and AURA2 phase II studies were tested for EGFR mutations by using tissue- and plasma-based cobas EGFR mutation tests. Plasma test performance was assessed by using the cobas tissue test and a next-generation sequencing method (MiSeq [Illumina Inc., San Diego, CA]) as references. The objective response rate, measured by blinded independent central review, was assessed in patients receiving osimertinib with a plasma T790M mutation-positive status. RESULTS: During screening, 551 patients provided matched tumor tissue and plasma samples. Pooled analysis of the positive and negative percent agreements between the cobas plasma and tissue tests for detection of T790M mutation were 61% and 79%, respectively. Comparing cobas plasma test with next-generation sequencing demonstrated positive and negative percent agreements of 90% or higher. The objective response rate was 64% (95% confidence interval: 57-70) in T790M mutation-positive patients by both cobas tissue and plasma tests (evaluable for response). CONCLUSIONS: The cobas plasma test detected the T790M mutation in 61% of tumor tissue T790M mutation-positive patients. To mitigate the risk of false-negative plasma results, patients with a negative plasma result should undergo a tissue test where feasible.

Osimertinib in Pretreated T790M-Positive Advanced Non-Small-Cell Lung Cancer: AURA Study Phase II Extension Component.

Purpose Osimertinib is an irreversible epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) selective for both EGFR-TKI sensitizing ( EGFRm) and T790M resistance mutations. AURA (NCT01802632) is a phase I/II clinical trial to determine the dose, safety, and efficacy of osimertinib. This article reports the results from the phase II extension component. Patients and Methods Patients with EGFR-TKI-pretreated EGFRm- and T790M-positive advanced non-small-cell lung cancer (NSCLC) received once-daily osimertinib 80 mg. T790M status was confirmed by central testing from a tumor sample taken after the most recent disease progression. Patients with asymptomatic, stable CNS metastases that did not require corticosteroids were allowed to enroll. The primary end point was objective response rate (ORR) by independent radiology assessment. Secondary end points were disease control rate, duration of response, progression-free survival (PFS), and safety. Patient-reported outcomes comprised an exploratory objective. Results In total, 201 patients received treatment, with a median treatment duration of 13.2 months at the time of data cutoff (November 1, 2015). In evaluable patients (n = 198), ORR was 62% (95% CI, 54% to 68%), and the disease control rate was 90% (95% CI, 85 to 94). Median duration of response in 122 responding patients was 15.2 months (95% CI, 11.3 to not calculable). Median PFS was 12.3 months (95% CI, 9.5 to 13.8). The most common possibly causally related adverse events (investigator assessed) were diarrhea (43%; grade ≥ 3, < 1%) and rash (grouped terms; 40%; grade ≥ 3, < 1%). Interstitial lung disease (grouped terms) was reported in eight patients (4%; grade 1, n = 2; grade 3, n = 3; grade 5, n = 3). Conclusion In patients with EGFRm T790M advanced NSCLC who progress after EGFR-TKI treatment, osimertinib provides a high ORR, encouraging PFS, and durable response.

Population pharmacokinetics and exposure-response of osimertinib in patients with non-small cell lung cancer.

AIMS: To develop a population (pop) pharmacokinetic (PK) model for osimertinib (AZD9291) and its metabolite (AZ5104) and investigate the exposure-response relationships for selected efficacy and safety parameters. METHODS: PK, safety and efficacy data were collected from two non-small cell lung cancer (NSCLC) patient studies (n = 748) and one healthy volunteer study (n = 32), after single or multiple once-daily dosing of 20-240 mg osimertinib. Nonlinear mixed effects modelling was used to characterise the popPK. Individual exposure values were used to investigate the relationship with response evaluation criteria in solid tumours (RECIST 1.1) efficacy parameters and key safety parameters (rash, diarrhoea, QTcF). RESULTS: A popPK model that adequately described osimertinib and its metabolite AZ5104 in a joint manner was developed. Body weight, serum albumin and ethnicity were identified as significant covariates on PK in the analysis, but were not found to have a clinically relevant impact on osimertinib exposure. No relationship was identified between exposure and efficacy over the dose range studied. A linear relationship was observed between exposure and the occurrence of rash or diarrhoea, and between concentration and QTcF, with a predicted mean (upper 90% confidence interval) increase of 14.2 (15.8) ms at the maximum concentration for an 80 mg once-daily dose at steady state. CONCLUSIONS: PopPK and exposure-response models were developed for osimertinib and AZ5104. There was no relationship between exposure and efficacy but a linear relationship between exposure and safety endpoints (rash, diarrhoea and QTcF) was observed.

Osimertinib for pretreated EGFR Thr790Met-positive advanced non-small-cell lung cancer (AURA2): a multicentre, open-label, single-arm, phase 2 study.

BACKGROUND: Osimertinib (AZD9291) is an oral, potent, irreversible EGFR tyrosine-kinase inhibitor selective for EGFR tyrosine-kinase inhibitor sensitising mutations, and the EGFR Thr790Met resistance mutation. We assessed the efficacy and safety of osimertinib in patients with EGFR Thr790Met-positive non-small-cell lung cancer (NSCLC), who had progressed after previous therapy with an approved EGFR tyrosine-kinase inhibitor. METHODS: In this phase 2, open-label, single-arm study (AURA2), patients aged at least 18 years with centrally confirmed EGFR Thr790Met-positive mutations, locally advanced or metastatic (stage IIIB/IV) NSCLC who progressed on previous EGFR tyrosine-kinase inhibitor therapy received osimertinib 80 mg orally once daily; treatment could continue beyond progression if the investigator observed a clinical benefit. Patients with asymptomatic, stable CNS metastases not requiring steroids were allowed to enrol. The primary endpoint was the proportion of patients achieving an objective response by blinded independent central review using Response Evaluation Criteria in Solid Tumors, version 1.1. Response endpoints were assessed in the evaluable for response analysis set (ie, all patients who received at least one dose of osimertinib and had measurable disease at baseline according to blinded independent central review). Other endpoints and safety were assessed in all patients receiving at least one osimertinib dose (full analysis set). The study is ongoing and patients are still receiving treatment. This study is registered with ClinicalTrials.gov, number NCT02094261. FINDINGS: Between May 20, 2014, and Sept 12, 2014, 472 patients were screened, of whom 210 started osimertinib treatment between June 13, 2014, and Oct 27, 2014; 11 patients were excluded from the evaluable for response analysis set (n=199) due to absence of measurable disease at baseline by blinded independent central review. At data cutoff (Nov 1, 2015), 122 (58%) patients remained on treatment. The median duration of follow-up was 13·0 months (IQR 7·6-14·2). 140 (70%; 95% CI 64-77) of 199 patients achieved an objective response by blinded independent central review: confirmed complete responses were achieved in six (3%) patients and partial responses were achieved in 134 (67%) patients. The most common all-causality grade 3 and 4 adverse events were pulmonary embolism (seven [3%]), prolonged electrocardiogram QT (five [2%]), decreased neutrophil count (four [2%]), anaemia, dyspnoea, hyponatraemia, increased alanine aminotransferase, and thrombocytopenia (three [1%] each). Serious adverse events were reported in 52 (25%) patients, of which 11 (5%) were investigator assessed as possibly treatment-related to osimertinib. Seven deaths were due to adverse events; these were pneumonia (n=2), pneumonia aspiration (n=1), rectal haemorrhage (n=1), dyspnoea (n=1), failure to thrive (n=1), and interstitial lung disease (n=1). The only fatal event assessed as possibly treatment-related by the investigator was due to interstitial lung disease. INTERPRETATION: Osimertinib showed clinical activity with manageable side-effects in patients with EGFR Thr790Met-positive NSCLC. Therefore, osimertinib could be a suitable treatment for patients with EGFR Thr790Met-positive disease who have progressed on an EGFR tyrosine-kinase inhibitor. FUNDING: AstraZeneca.

Preclinical Comparison of Osimertinib with Other EGFR-TKIs in EGFR-Mutant NSCLC Brain Metastases Models, and Early Evidence of Clinical Brain Metastases Activity.

PURPOSE: Approximately one-third of patients with non-small cell lung cancer (NSCLC) harboring tumors with EGFR-tyrosine kinase inhibitor (TKI)-sensitizing mutations (EGFRm) experience disease progression during treatment due to brain metastases. Despite anecdotal reports of EGFR-TKIs providing benefit in some patients with EGFRm NSCLC brain metastases, there is a clinical need for novel EGFR-TKIs with improved efficacy against brain lesions. EXPERIMENTAL DESIGN: We performed preclinical assessments of brain penetration and activity of osimertinib (AZD9291), an oral, potent, irreversible EGFR-TKI selective for EGFRm and T790M resistance mutations, and other EGFR-TKIs in various animal models of EGFR-mutant NSCLC brain metastases. We also present case reports of previously treated patients with EGFRm-advanced NSCLC and brain metastases who received osimertinib in the phase I/II AURA study (NCT01802632). RESULTS: Osimertinib demonstrated greater penetration of the mouse blood-brain barrier than gefitinib, rociletinib (CO-1686), or afatinib, and at clinically relevant doses induced sustained tumor regression in an EGFRm PC9 mouse brain metastases model; rociletinib did not achieve tumor regression. Under positron emission tomography micro-dosing conditions, [11C]osimertinib showed markedly greater exposure in the cynomolgus monkey brain than [11C]rociletinib and [11C]gefitinib. Early clinical evidence of osimertinib activity in previously treated patients with EGFRm-advanced NSCLC and brain metastases is also reported. CONCLUSIONS: Osimertinib may represent a clinically significant treatment option for patients with EGFRm NSCLC and brain metastases. Further investigation of osimertinib in this patient population is ongoing. Clin Cancer Res; 22(20); 5130-40. ©2016 AACR.

Association Between Plasma Genotyping and Outcomes of Treatment With Osimertinib (AZD9291) in Advanced Non-Small-Cell Lung Cancer.

PURPOSE: Third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have demonstrated potent activity against TKI resistance mediated by EGFR T790M. We studied whether noninvasive genotyping of cell-free plasma DNA (cfDNA) is a useful biomarker for prediction of outcome from a third-generation EGFR-TKI, osimertinib. METHODS: Plasma was collected from all patients in the first-in-man study of osimertinib. Patients who were included had acquired EGFR-TKI resistance and evidence of a common EGFR-sensitizing mutation. Genotyping of cell-free plasma DNA was performed by using BEAMing. Plasma genotyping accuracy was assessed by using tumor genotyping from a central laboratory as reference. Objective response rate (ORR) and progression-free survival (PFS) were analyzed in all T790M-positive or T790M-negative patients. RESULTS: Sensitivity of plasma genotyping for detection of T790M was 70%. Of 58 patients with T790M-negative tumors, T790M was detected in plasma of 18 (31%). ORR and median PFS were similar in patients with T790M-positive plasma (ORR, 63%; PFS, 9.7 months) or T790M-positive tumor (ORR, 62%; PFS, 9.7 months) results. Although patients with T790M-negative plasma had overall favorable outcomes (ORR, 46%; median PFS, 8.2 months), tumor genotyping distinguished a subset of patients positive for T790M who had better outcomes (ORR, 69%; PFS, 16.5 months) as well as a subset of patients negative for T790M with poor outcomes (ORR, 25%; PFS, 2.8 months). CONCLUSION: In this retrospective analysis, patients positive for T790M in plasma have outcomes with osimertinib that are equivalent to patients positive by a tissue-based assay. This study suggests that, upon availability of validated plasma T790M assays, some patients could avoid a tumor biopsy for T790M genotyping. As a result of the 30% false-negative rate of plasma genotyping, those with T790M-negative plasma results still need a tumor biopsy to determine presence or absence of T790M.

Metabolic Disposition of Osimertinib in Rats, Dogs, and Humans: Insights into a Drug Designed to Bind Covalently to a Cysteine Residue of Epidermal Growth Factor Receptor.

Preclinical and clinical studies were conducted to determine the metabolism and pharmacokinetics of osimertinib and key metabolites AZ5104 and AZ7550. Osimertinib was designed to covalently bind to epidermal growth factor receptors, allowing it to achieve nanomolar cellular potency (Finlay et al., 2014). Covalent binding was observed in incubations of radiolabeled osimertinib with human and rat hepatocytes, human and rat plasma, and human serum albumin. Osimertinib, AZ5104, and AZ7550 were predominantly metabolized by CYP3A. Seven metabolites were detected in human hepatocytes, also observed in rat or dog hepatocytes at similar or higher levels. After oral administration of radiolabeled osimertinib to rats, drug-related material was widely distributed, with the highest radioactivity concentrations measured at 6 hours postdose in most tissues; radioactivity was detectable in 42% of tissues 60 days postdose. Concentrations of [(14)C]-radioactivity in blood were lower than in most tissues. After the administration of a single oral dose of 20 mg of radiolabeled osimertinib to healthy male volunteers, ∼19% of the dose was recovered by 3 days postdose. At 84 days postdose, mean total radioactivity recovery was 14.2% and 67.8% of the dose in urine and feces. The most abundant metabolite identified in feces was AZ5104 (∼6% of dose). Osimertinib accounted for ∼1% of total radioactivity in the plasma of non-small cell lung cancer patients after 22 days of 80-mg osimertinib once-daily treatment; the most abundant circulatory metabolites were AZ7550 and AZ5104 (<10% of total osimertinib-related material). Osimertinib is extensively distributed and metabolized in humans and is eliminated primarily via the fecal route.