Phase II Clinical Trial of First or Second-Line Treatment with Bortezomib in Patients with Malignant Pleural Mesothelioma
Authors: Dean A. Fennell, Cliona McDowell, Sara Busacca, Glen Webb, Brian Moulton, Andrew Cakana, Kenneth J. O’Byrne, Jan V. Meerbeeck, Paul Donnellan, John McCaffrey, Paul Baas
Journal: Journal of Thoracic Oncology (2012)

Based on promising preclinical efficacy of bortezomib in mesothelioma, a single-arm phase II trial (Ireland Cooperative Oncology Research Group 05-10 study), with Simon's two-stage design, was undertaken to assess efficacy of bortezomib monotherapy in the first-line (poor performance status) and second-line settings. The Bcl-2 homology domain 3-only protein Noxa has been implicated as a key inducer of apoptosis by bortezomib. Thus, in a biomarker research substudy, we hypothesized that deficiency in Noxa expression might correlate with resistance. In the second-line setting, 23 patients were enrolled. Partial response was confirmed in one patient (4.8%) who received four cycles of bortezomib. One patient had stable disease; however, progression occurred in the majority of patients within the first two cycles. Median progression-free survival and overall survival were 2.1 and 5.8 months, respectively. In the first-line setting, ten patients were accrued, and there was no evidence of objective response. In the tumor analysis, expression of Noxa was seen in all biopsies. Bortezomib monotherapy exhibits insufficient activity to warrant further investigation in unselected patients with mesothelioma. Based on promising preclinical efficacy of bortezomib in mesothelioma, a single-arm phase II trial (Ireland Cooperative Oncology Research Group 05-10 study), with Simon's two-stage design, was undertaken to assess efficacy of bortezomib monotherapy in the first-line (poor performance status) and second-line settings. The Bcl-2 homology domain 3-only protein Noxa has been implicated as a key inducer of apoptosis by bortezomib. Thus, in a biomarker research substudy, we hypothesized that deficiency in Noxa expression might correlate with resistance. In the second-line setting, 23 patients were enrolled. Partial response was confirmed in one patient (4.8%) who received four cycles of bortezomib. One patient had stable disease; however, progression occurred in the majority of patients within the first two cycles. Median progression-free survival and overall survival were 2.1 and 5.8 months, respectively. In the first-line setting, ten patients were accrued, and there was no evidence of objective response. In the tumor analysis, expression of Noxa was seen in all biopsies. Bortezomib monotherapy exhibits insufficient activity to warrant further investigation in unselected patients with mesothelioma. The incidence of malignant pleural mesothelioma (MPM) is increasing in Europe and this trend is set to continue over the next decade.1Robinson BW Lake RA Advances in malignant mesothelioma.N Engl J Med. 2005; 353: 1591-1603Crossref PubMed Scopus (909) Google Scholar The majority of patients present with advanced disease for which systemic therapy is the standard of care.2Fennell DA Gaudino G O'Byrne KJ Mutti L van Meerbeeck J Advances in the systemic therapy of malignant pleural mesothelioma.Nat Clin Pract Oncol. 2008; 5: 136-147Crossref PubMed Google Scholar Pemetrexed-cisplatin is the standard treatment for patients in the first-line setting.3Vogelzang NJ Rusthoven JJ Symanowski J et al.Phase III study of pemetrexed in combination with cisplatin versus cisplatin alone in patients with malignant pleural mesothelioma.J Clin Oncol. 2003; 21: 2636-2644Crossref PubMed Scopus (2497) Google Scholar However, there is currently no approved standard of care for patients who have relapsed. Several trials have failed to show useful activities in the second-line setting.4Ramalingam SS Belani CP Ruel C et al.Phase II study of belinostat (PXD101), a histone deacetylase inhibitor, for second line therapy of advanced malignant pleural mesothelioma.J Thorac Oncol. 2009; 4: 97-101Abstract Full Text Full Text PDF PubMed Scopus (144) Google Scholar Bortezomib is an inhibitor of the 20s proteasome and is licenced for the treatment of myeloma. Bortezomib activates the intrinsic apoptotic pathway by transcriptionally up-regulating the proapoptotic B-cell lymphoma 2 family proteins Noxa, p53 upregulated modulator of apoptosis, and bcl-2 interacting mediator of cell death (BIM).6Fennell DA Chacko A Mutti L BCL-2 family regulation by the 20S proteasome inhibitor bortezomib.Oncogene. 2008; 27: 1189-1197Crossref PubMed Scopus (130) Google Scholar In preclinical models of mesothelioma, bortezomib has demonstrated promising activity, warranting its therapeutic evaluation.7Sartore-Bianchi A Gasparri F Galvani A et al.Bortezomib inhibits nuclear factor-kappaB dependent survival and has potent in vivo activity in mesothelioma.Clin Cancer Res. 2007; 13: 5942-5951Crossref PubMed Scopus (82) Google Scholar Accordingly, the Ireland Cooperative Oncology Research Group 05-10 clinical trial was designed to evaluate the efficacy of bortezomib monotherapy in the second-line patients and in patients who were unfit to or were unwilling to receive first-line platinum-based chemotherapy. Patients were considered eligible if they had histological evidence of MPM, performance status of 0 to 2 by Eastern Cooperative Group (ECOG) criteria, adequate hematological status (hemoglobin ≥10 g/dL; neutrophil count ≥1.5 × 109/liter; and platelets ≥ 100 × 109/liter), adequate hepatic function (aspartate transaminase and alanine transaminase <3 × upper limit of normal), adequate renal function (creatinine clearance ≥50 ml/min determined by Cockcroft–Gault method). There was a requirement where possible for pleural effusions to be drained before treatment and for uncontrolled pleural effusions to be managed as per standard practice by talc or tetracycline pleurodesis. For patients in the chemo-naive treatment setting, they had to be either unsuitable for or not willing to receive combination chemotherapy. All patients provided consent to participate in this study, which was conducted according to the International Conference on Harmonisation—Good Clinical Practice standards. Baseline evaluation included routine hematology and biochemistry, which were required on the first day of each treatment cycle. Computed tomography (CT) scan of the involved areas (chest, plus abdomen, or pelvis) was conducted a maximum of 28 days before commencing bortezomib. Repeat CT scans were conducted after every two treatment cycles. Responding patients had a further confirmatory CT scan at 1 month. Patients received bortezomib at 1.6 mg/m2 administered weekly on days 1, 8, 15, and 22 of a 35-day (5-week) cycle. This schedule was determined as the maximum tolerated dose reported for patients with androgen-resistant prostate cancer, treated in a phase 1 trial.9Papandreou CN Daliani DD Nix D et al.Phase I trial of the proteasome inhibitor bortezomib in patients with advanced solid tumors with observations in androgen-independent prostate cancer.J Clin Oncol. 2004; 22: 2108-2121Crossref PubMed Scopus (428) Google Scholar Treatment was continued until disease progression in those patients exhibiting objective responses or stable disease by 20 weeks. Dose adjustments were made for common toxicity criteria grade 3 or 4 toxicities. Only two dose reductions were permitted, after which treatment was discontinued. Immunohistochemistry was performed on 18 paraffin-embedded primary mesothelioma tissues. The staining was carried out, as previously described,10Jansson AK Emterling AM Arbman G Sun XF Noxa in colorectal cancer: a study on DNA, mRNA and protein expression.Oncogene. 2003; 22: 4675-4678Crossref PubMed Scopus (29) Google Scholar with a 1:200 dilution of a monoclonal antibody against Noxa (OP180; Oncogene Science, San Diego, CA) for 2 hours. Isotype immunoglobin G1 was used as negative control. The Noxa immunohistochemistry scoring of tissue microarray slides was carried out using the PathXLTMA Toolbox (i-Path Diagnostics Ltd, Belfast, United Kingdom). Through this application, the lung pathologist could remotely access high resolution slide scans and perform scoring. Noxa-positive tumors were defined as those demonstrating 10% or more cells with staining. The primary end point was response rate measured by modified Response Evaluation Criteria In Solid Tumors criteria.11Byrne MJ Nowak AK Modified RECIST criteria for assessment of response in malignant pleural mesothelioma.Ann Oncol. 2004; 15: 257-260Crossref PubMed Scopus (528) Google Scholar Secondary end points were time to progression and overall survival. A two-stage optimal Simon's design based on the observed tumor response was employed. Second-line hypothesis tested: p0 ⩽ 0.05 and p1 ≥ 0.17 (α = 0.05, β = 0.1) requiring n = 23 patients and 2 responders to continue to N=70 in total. First-line: p0 ⩽ 0.1, p1 ≥ 0.25 (α = 0.05, β = 0.1), stage one sample N = 21, requiring 3 responders to continue to N = 66. In the first-line setting, 10 patients were enrolled between July 19, 2006 and October 29, 2009, of whom nine were eligible for response and toxicity assessment. Because of slow accrual, enrollment was discontinued prematurely. The patient characteristics are summarized in Table 1. The majority of patients were men, with a median age of 67.9 (range, 59–81), epithelioid histology, and ECOG performance status of 0 to 1 in 80%. Patients received a median of three treatment cycles (range, 1–4) with a total of 28 cycles administered to 10 patients; 10 patients (100%) completed cycle 1, 8 patients (89%) completed cycle 2, 5 patients (50%) completed cycle 3, and 3 patients (30%) completed cycle 4.TABLE 1Summary of Patient Characteristics (First-Line and Second-Line Bortezomib)CharacteristicFirst-LineSecond-LineN=10N=23Sex Men8 (80%)20 (87%) Women2 (20%)3 (13%)Age Median6765 >704 (40%)6 (26%)Histology Epithelioid3 (30%)16 (70%) Sarcamatoid1 (10%)2 (9%) Mixed (biphasic)1 (10%)1 (4%)1 (4%) Subtype, unknown5 (50%)3 (13%)ECOG performance status 03 (30%)5(2 15 (50%)17 (74%) 22 (20%)0 (0%)1 (4%)White cell count at baseline Mean (SD)9.6 (2.47)9.0 (3.55)ECOG, Eastern Cooperative Oncology Group. Open table in a new tab ECOG, Eastern Cooperative Oncology Group. No patient received more than 4 cycles of bortezomib. Grade 3 or 4 toxicities associated with bortezomib are shown in Table 2. Dose reductions occurred in no patient. Discontinuation because of adverse reactions occurred in one patient attributable to grade 2 toxicity (atrial fibrillation and congestive heart failure), after study withdrawal but within 30 days of last treatment.TABLE 2Patient Counts of Adverse Events By Maximum Toxicity by Treatment Line n (%)CTC GradeTotal1234First line1 (10%)5 (50%)4 (40%)0 (0%)10 (100%)Second line2 (8.7%)11 (47.8%)6 (26.1%)4 (17.4%)23 (100%)CTC, common toxicity criteria. Open table in a new tab CTC, common toxicity criteria. In the efficacy population, no patient had a partial response, and one patient (11 %) had stable disease during four cycles of treatment. Progressive disease in the first two cycles occurred in 5 patients (56%), and 5 patients (56%) progressed before cycle 4. There were 2 deaths (22%) before completion of four cycles of therapy, both of which occurred after study withdrawal and within 30 days of last treatment. Median time to progression was 2.23 months, Figure 1A, and median overall survival was 10.55 months, Figure 1B. In the second-line setting, 23 patients were enrolled between May 23, 2006 and October 18, 2007 and 21 were eligible for response and toxicity. The patient characteristics are summarized in Table 1. The majority of patients were men, with a median age of 64.7 (range, 49–78), 65% of patients had epithelioid histology and ECOG performance status of 0 to 1 (96%). Patients received a median of two treatment cycles (range, 1–4), and a total of 49 cycles were administered to 23 patients. No patient received more than four cycles of bortezomib; 21 patients (91%) completed cycle 1, 17 patients (74%) completed cycle 2, 3 patients (13%) completed cycle 3, and 2 patients (9%) completed cycle 4. Grade 3 or 4 toxicities associated with bortezomib are shown in Table 2. Dose reductions occurred for 3 patients because of grade 3 anemia, fatigue, and peripheral sensory neuropathy, respectively. Discontinuation because of adverse toxicities occurred in 1 patient attributable to a grade 4 event (fecal impaction). One patient (4.8% of efficacy population) had a partial response, which was confirmed and associated with reduction in the size of an invasive chest-wall mass. The responder was a man with epithelioid histology, who had received carboplatin and pemetrexed in the first-line setting with stable disease as best overall response. This patient went on to receive a total of four cycles of bortezomib (cycles 2–4 at a reduced dose of 1.3 mg/m2). This patient relapsed in the sixth month of follow-up, and died in the 22nd month of follow-up. In the efficacy population, 1 patient (4.8%) had stable disease for one to four cycles. Progressive disease occurred in the first two cycles in 86% of the patients, and 19 patients (90%) had progressed before cycle four. There were 7 deaths (33%) before completion of four cycles of therapy, five of which (23.8%) occurred after study withdrawal and within 30 days of last treatment. Median time to progression was 2.1 months, Figure 1C, and median overall survival was 5.78 months, Figure 1D. On the basis of the observed response rate in the first stage of the study, the null hypothesis was accepted, and it was decided to discontinue accrual. Preclinical data has demonstrated that lack of Noxa expression leads to a significant attenuation of bortezomib toxicity.12Zhang L Littlejohn JE Cui Y Cao X Peddaboina C Smythe WR Characterization of bortezomib-adapted I-45 mesothelioma cells.Mol Cancer. 2010; 9: 110Crossref PubMed Scopus (23) Google Scholar We therefore hypothesised that constitutive deficiency in Noxa expression might correlate with resistance to bortezomib. By using a predefined threshold of less than 10% of Noxa expression for defining immunonegativity, we conducted pathological review of 18 archival mesothelioma specimens. No immunonegative samples were found as Noxa was expressed in all samples from patients receiving bortezomib, Figure 2. Based on promising in vivo preclinical data, we undertook a multicenter phase II trial in the first- and second-line setting. Single agent efficacy was insufficient in the first stage to justify enrollment into the second stage. Enrolment was also confounded by difficulty in identifying sufficient patients with an ECOG Performance Status of 2 who were suitable for enrollment, most patients being sufficiently fit to receive standard treatment. There have been few reported clinical trials in the second-line treatment setting in MPM, mainly single-arm, nonrandomized studies. To date there has been only one large randomized phase III trial, in which patients received pemetrexed or best supportive care. Although activity (progression-free survival increase) was evident in the experimental arm, there was no significant impact on overall survival.13Jassem J Ramlau R Santoro A et al.Phase III trial of pemetrexed plus best supportive care compared with best supportive care in previously treated patients with advanced malignant pleural mesothelioma.J Clin Oncol. 2008; 26: 1698-1704Crossref PubMed Scopus (202) Google Scholar At present there is no standard of care for patients with MPM who have progressed after pemetrexed-cisplatin. We considered bortezomib to be a promising drug because of its effects in preclinical mesothelioma models.7Sartore-Bianchi A Gasparri F Galvani A et al.Bortezomib inhibits nuclear factor-kappaB dependent survival and has potent in vivo activity in mesothelioma.Clin Cancer Res. 2007; 13: 5942-5951Crossref PubMed Scopus (82) Google Scholar The protein Noxa has been implicated in mediating the proapoptotic effects of bortezomib in several cancers6Fennell DA Chacko A Mutti L BCL-2 family regulation by the 20S proteasome inhibitor bortezomib.Oncogene. 2008; 27: 1189-1197Crossref PubMed Scopus (130) Google Scholar, 14Chen S Blank JL Peters T et al.Genome-wide siRNA screen for modulators of cell death induced by proteasome inhibitor bortezomib.Cancer Res. 2010; 70: 4318-4326Crossref PubMed Scopus (79) Google Scholar and was suggested as a preclinical biomarker for responsiveness to bortezomib treatment in vitro and in vivo. However, it was demonstrated that the induction of Noxa is necessary but not sufficient for bortezomib-induced apoptosis in neuroblastoma cells; indeed Noxa can act as sensitzser but does not induce death per se.15Combaret V Boyault S Iacono I Brejon S Rousseau R Puisieux A Effect of bortezomib on human neuroblastoma: analysis of molecular mechanisms involved in cytotoxicity.Mol Cancer. 2008; 7: 50Crossref PubMed Scopus (33) Google Scholar Here, we show that Noxa is equally expressed in all the analyzed samples irrespective of the response to bortezomib treatment, disproving its role as a biomarker in mesothelioma. In summary, bortezomib as a monotherapy exhibits insufficient activity to warrant its further investigation in unselected patients with MPM. This study was funded by an investigator-led clinical trial grant from Johnson & Johnson.