Michael Emig

A substantial minority of patients with chronic myelogenous leukemia (CML) achieve a complete response (CR) to treatment with interferon-alpha (IFN), defined as the disappearance of Philadelphia chromosome-positive metaphases. Currently it is unclear how long IFN treatment should be continued for such patients. We used a competitive reverse transcriptase-polymerase chain reaction (RT-PCR) to quantify levels of BCR-ABL transcripts in 297 peripheral blood specimens collected from 54 patients who had achieved CR with IFN. The median duration of observation was 1.9 years (range, 0.3-11.0 years). Total ABL transcripts were quantified as internal control and results were expressed as the ratio BCR-ABL/ABL. All 54 patients had molecular evidence of residual disease, although 3 patients were intermittently PCR negative. The median BCR-ABL/ABL ratio at the time of maximal response for each patient was 0.045% (range, 0%-3. 6%). During the period of observation 14 patients relapsed, 11 cytogenetically to chronic phase disease and 3 directly to blastic phase. The median ratio of BCR-ABL/ABL at maximal response was significantly higher in patients who relapsed than in those who remained in CR (0.49% versus 0.021%, P < 0.0001). Our findings show that the level of residual disease falls with time in complete responders to IFN, but molecular evidence of disease is rarely if ever eliminated. The actual level of minimal residual disease correlates with the probability of relapse. We suggest that for patients who reach CR, IFN should be continued at least until relatively low levels of residual leukemia are achieved. (Blood. 2000;95:62-66)

3 Background: Epidermal growth factor receptor (EGFR) dysregulation is common in NSCLC and is associated with poorer prognosis. This phase III study assessed the efficacy and safety of the EGFR-targeted monoclonal antibody cetuximab in combination with cisplatin/vinorelbine (CV) compared with CV alone in advanced NSCLC. Methods: Patients with EGFR- detectable advanced NSCLC were randomized 1:1 to cetuximab (400 mg/m2 initial dose, then 250 mg/m2/wk) plus C (80 mg/m2 d1) and V (25 mg/m2 d1, d8) q3w (arm A) or CV alone (arm B). The primary endpoint was overall survival (OS); secondary endpoints were progression-free survival, tumor response, disease control, and safety. Randomization was stratified by ECOG performance status (0/1 vs 2) and tumor stage (wet IIIb vs IV). Results: 1,125 patients were randomized: 557 to arm A, 568 to arm B, 70% male, median age 59 (18–83) years, 94% stage IV, 47% adenocarcinoma (AC), 34% squamous cell carcinoma (SCC), 83% ECOG 0/1. Survival analysis was performed after 868 events had occurred. OS was significantly improved in arm A (stratified log-rank test). Preliminary results of prespecified subgroup analyses suggest a greater benefit in Caucasians independent of histology and a general better prognosis in Asians. Analyses of secondary endpoints are ongoing. Conclusions: Cetuximab plus CV demonstrated superior survival over CV alone in patients with advanced EGFR-detectable NSCLC. There was a remarkable difference between the outcome of Asian and Caucasian patients. This is the first study to demonstrate a survival benefit of an EGFR- targeted agent in combination with platinum-based chemotherapy in advanced first-line NSCLC irrespective of histology and confirms the clinical relevance of cetuximab in NSCLC. MedianOS (mo) Arm A Median OS (mo) Arm B HR[95% CI] p-value All (n=1125) 11.3 10.1 0.871 [0.762–0.996] 0.0441 Caucasians (n=945) 10.5 9.1 0.800 [0.692–0.924] 0.0025 with AC (n=412) 12.0 10.2 0.809 [0.644–1.016] 0.0673 with SCC (n=347) 10.2 8.9 0.794 [0.626–1.007] 0.0567 Asians (n=121) 17.6 20.4 1.179 [0.730–1.905] Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Expert Testimony Other Remuneration Merck Serono Merck