Virtual Library

Start Your Search

T.S.K. Mok



Author of

  • +

    MO06 - NSCLC - Chemotherapy I (ID 108)

    • Event: WCLC 2013
    • Type: Mini Oral Abstract Session
    • Track: Medical Oncology
    • Presentations: 1
    • +

      MO06.04 - A Randomized Phase 3 Study Comparing First-line Pemetrexed plus Cisplatin Followed by Gefitinib as Maintenance with Gefitinib Monotherapy in East Asian Patients with Locally Advanced or Metastatic Nonsquamous Non-Small Cell Lung Cancer (nSqNSCLC) (ID 1943)

      16:15 - 17:45  |  Author(s): T.S.K. Mok

      • Abstract
      • Presentation
      • Slides

      Background
      The IPASS study reported that in a clinically selected lung cancer patient population (East Asian, light ex-/nonsmokers with adenocarcinoma) gefitinib (G) provided superior progression-free survival (PFS) than chemotherapy with carboplatin/paclitaxel; however, the benefit was restricted to patients with epidermal growth factor receptor gene (EGFR)-mutant tumors whereas patients with wild-type (WT) tumors had inferior outcomes. Pemetrexed, in combination with cisplatin, (PC) has demonstrated improved efficacy in first-line treatment of nSqNSCLC and is a preferred chemotherapy choice. The primary objective was to compare PC induction therapy followed by G as maintenance therapy to G monotherapy, in terms of PFS, as first-line treatment in a similar “IPASS” patient population.

      Methods
      Patients with unknown EGFR mutation status (N=236) were randomized 1:1 to PCG treatment for 6 cycles or G. Patients on Arm A without progressive disease after 6 cycles received G maintenance therapy. Stage IIIB/IV nSQ NSCLC, light ex-smokers or never-smokers, and ECOG PS 0-1 patients with no prior systemic therapy were eligible. Primary endpoint analysis was conducted using a Wilcoxon test after 169 PFS events. This assessment provided 80% power if the true hazard ratio (HR) was 0.65. Tissue samples from consenting patients were analyzed for EGFR mutation status.

      Results
      Baseline characteristics were balanced across treatment arms. One-hundred-forty-one patients provided tissue for EGFR mutation analysis (59.7%). Mutation status was determined for 74 samples (52.5%);50/74 samples (67.6%) had mutations (mutation type: EX19_DEL, n=25; L858R, n=23; other, n=2). The primary analysis of PFS showed no significant difference between treatment arms (Wilcoxon p=0.217). The unadjusted HR was 0.85 (95% CI: 0.63, 1.13). During most of the study period, the KM curve for PC remained above the G curve. In a prespecified subgroup analysis, EGFR-by-treatment interaction was statistically significant (p=0.008), showing treatment effect significantly differed by EGFR mutation status. The HR for PFS favored PC in both EGFR-mutated and EGFR-WT patients, but the magnitude of benefit was greater in EGFR-WT patients [EGFR-mutated patients HR=0.83 ([95% CI: 0.42, 1.62], p=0.585); EGFR-WT HR 0.18 ([95% CI: 0.06, 0.51], p=0.001)]. HRs for ITT and EGFR-mutated patients should be interpreted with caution as they were not constant. Arm A had more patients with ≥1 possibly drug-related CTCAE grade 3/4 TEAEs but similar rates of all-grade TEAEs during induction. Selected grade 3/4 or all-grade TEAEs which occurred significantly more included anemia, neutropenia, emesis, and neuropathy in Arm A and AST/ALT elevations, diarrhea, pruritus, and skin rash in Arm B. The toxicity profile was similar in both arms during the G maintenance period.

      Conclusion
      In the ITT population, the PFS difference was not statistically significant. In the biomarker assessable population, results are consistent with the existing consensus that patients with WT EGFR do not benefit with front-line EGFR TKI treatment. Overall, the results show that identification of the EGFR mutational status is key in the management of advanced NSCLC. Even in the presence of clinically favorable predictors of EGFR mutation positivity (>60% in our population), “empirical” choice of EGFR TKIs as front-line therapy may be detrimental to NSCLC patients without EGFR mutations.

      Only Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login, select "Add to Cart" and proceed to checkout. If you would like to become a member of IASLC, please click here.

      Only Active Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login or select "Add to Cart" and proceed to checkout.

  • +

    O03 - NSCLC - Targeted Therapies I (ID 113)

    • Event: WCLC 2013
    • Type: Oral Abstract Session
    • Track: Medical Oncology
    • Presentations: 1
    • +

      O03.05 - Activity of afatinib in uncommon epidermal growth factor receptor (EGFR) mutations: Findings from three trials of afatinib in EGFR mutation-positive lung cancer (ID 1114)

      10:30 - 12:00  |  Author(s): T.S.K. Mok

      • Abstract
      • Presentation
      • Slides

      Background
      EGFR (ErbB1) mutations define a lung cancer subtype with exquisite sensitivity to EGFR tyrosine kinase inhibitors (TKIs). While in-frame deletion in exon 19 (Del19) and a point mutation (L858R) in exon 21 are the two most common sensitizing EGFR mutations in non-small cell lung cancer (NSCLC), approximately 10% of EGFR mutation-positive tumours harbour uncommon mutations. These mutations represent a heterogeneous group of rare molecular alterations (or combinations) within exons 18–21, whose oncogenicity and sensitivity to EGFR TKIs may vary and has not been prospectively studied. Here we present the first prospective data series on activity of afatinib, the irreversible ErbB Family Blocker, in patients with tumours harbouring uncommon EGFR mutations.

      Methods
      This analysis is based on data from EGFR mutation-positive patients included in the LUX-Lung 2 (Phase II), LUX-Lung 3 and LUX-Lung 6 (both Phase III) studies. EGFR mutations were identified prospectively by direct sequencing in LUX-Lung 2 and by central testing with TheraScreen EGFR RGQ PCR kit (TheraScreen29) in LUX-Lung 3 and 6. Patients were classified as having common (Del19 or L858R) or uncommon (all other single or complex) mutations. Uncommon mutations were categorized into three groups: de novo T790M (alone or in combination with other mutations); exon 20 insertions; and other. Objective response rate (ORR), disease control (DCR), duration of response and progression-free survival (PFS) were assessed by independent review.

      Results
      Seventy-five patients (LUX-Lung 2: n=23; LUX-Lung 3: n=26; and LUX-Lung 6: n=26) had uncommon mutations, accounting for 12.5% of all afatinib patients in these studies. The majority of patients received afatinib first line; 13 patients from LUX-Lung 2 received afatinib after chemotherapy. Breakdown into the three groups was T790M: n=14; Exon 20 insertions: n=23; other: n=38 (most frequent types were L861Q: n=12; G719X: n=8; G719X+S768I: n= 5; G719X+L861Q: n=3). Efficacy results for each group are shown below. Further details by mutation status will be presented.

      Mutation ORR, % (n=) Median duration of response, months (95% confidence interval) DCR (ORR + stable disease), % (n) Median PFS, months (95% confidence interval) Median survival, months (95% confidence interval)
      De novo T790M alone or in combination with other mutations (n=14) 14.3 (2) Individual response durations: 4.1, 12.4 64.2 (9) 2.9 (1.2−8.3) 14.9 (8.1−24.9)
      Exon 20 insertions (n=23) 8.7 (2) Individual response durations: 4.2, 10.1 65.2 (15) 2.7 (1.8−4.2) 9.4 (4.1−21.0)
      Other (n=38) 71.1 (27) 11.1 (4.1, 15.2) 84.2 (32) 10.7 (5.6−14.7) 18.6 (16.4−not estimable)

      Conclusion
      Afatinib was active in lung tumours harbouring uncommon EGFR mutations, such as G719X, L861Q, S768I. Rate and duration of response was comparable with that previously observed in patients with common mutations in these trials. The response rate was low in tumours with de novo T790M mutations and insertions in exon 20 but durable tumour control was achieved in some patients. To date this is the largest analysis of data for prospectively identified patients with uncommon EGFR mutations; treatment options in this heterogeneous group of tumours will be discussed.

      Only Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login, select "Add to Cart" and proceed to checkout. If you would like to become a member of IASLC, please click here.

      Only Active Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login or select "Add to Cart" and proceed to checkout.

  • +

    P3.11 - Poster Session 3 - NSCLC Novel Therapies (ID 211)

    • Event: WCLC 2013
    • Type: Poster Session
    • Track: Medical Oncology
    • Presentations: 1
    • +

      P3.11-011 - Serum albumin as a potential pharmacodynamic biomarker in patients treated with the anti-hepatocyte growth factor monoclonal antibody ficlatuzumab (ID 1067)

      09:30 - 16:30  |  Author(s): T.S.K. Mok

      • Abstract

      Background
      Ficlatuzumab is an anti-hepatocyte growth factor (HGF) monoclonal antibody (mAb) being tested in clinical trials for cancer. Hypoalbuminemia has been observed in these trials, as well as in trials with other HGF/c-Met inhibitory mAbs. The relationship between serum albumin (SA) and ficlatuzumab treatment is examined.

      Methods
      Ficlatuzumab was studied in P05538, a first-in-human dose escalation trial; in P05670, a dose ranging trial investigating the pharmacodynamic (PD) effect of ficlatuzumab; and in P06162, a phase II study in combination with gefitinib (FG arm) versus gefitinib alone (G arm) in NSCLC patients. Patient data from these studies were evaluated longitudinally for peripheral edema, changes in SA, serum Ca[2+] (Ca), liver function tests (LFTs), prothrombin time (PT) and proteinuria.

      Results
      In P05538, all 23 evaluable patients had SA decrease with median change to nadir of -29% (-46 to -11%) and median nadir SA level of 25 g/L (15 to 33 g/L). In P05670, all 19 evaluable patients had decreased SA, with median change to nadir of -20% (-49 to -7%) and median nadir SA level of 31 g/L (14 to 40 g/L). In P06162, 88 of 90 (98%) evaluable patients in FG arm experienced SA decrease, with a median nadir change of -27% (range -62 to 8%). No significant SA changes were observed in the G arm. LFTs and PT were not significantly changed in any of the trials. Peripheral edema was observed in 52%, 32%, 38%, and 4% of the patients in P05538, P05670, FG, and G arms of P06162, respectively. In P06162, low Ca laboratory findings (not corrected for albumin) were reported in 72% of patients, with median change to nadir of -11% (-24% to 5%). Changes in uncorrected Ca were secondary to changes in albumin (% changes Pearson correlation=0.68, P<0.0001). No difference in the rate of proteinuria was observed across FG and G arms of the 6162 trial.

      Conclusion
      Decrease in SA during ficlatuzumab treatment was seen in almost all patients and appears to be unrelated to hepatotoxicity. Decrease in SA resulting from ficlatuzumab treatment may be the cause of peripheral edema. Both hypoalbuminemia and peripheral edema were frequently observed with other HGF/c-Met inhibitors, suggesting they may be class adverse events. Decrease in SA could be explored as a PD marker for HGF/c-Met inhibition.