Robert N. Taub

Phase II Trial of a Single Weekly Intravenous Dose of Ranpirnase in Patients With Unresectable Malignant Mesothelioma

PURPOSE A multicenter phase II trial of ranpirnase (Onconase; Alfacell Corp, Bloomfield, NJ) as a single agent was conducted to further assess the safety and clinical efficacy of this novel antitumor ribonuclease. Patients with unresectable and histologically confirmed malignant mesothelioma (MM) were eligible. PATIENTS AND METHODS One hundred five patients with Eastern Cooperative Oncology Group performance status 0 to 2 were enrolled onto the study. Thirty-seven percent of patients had not responded to prior chemotherapy. The primary end point of the study was survival. Tumor responses and time to progression were also assessed. The Cancer and Leukemia Group B (CALGB) prognostic group criteria were used to define a treatment target group (TTG). Both the intent-to-treat (ITT) and the TTG populations were analyzed for survival. RESULTS Median survival times of 6 months for the ITT and 8.3 months for the TTG populations were observed. The 1- and 2-year survival rates were 34.3% and 21.6% for ITT, respectively, and 42% and 26.8% for TTG, respectively. Among the 81 patients assessable for tumor response, four had partial responses, two had minor regressions, and thirty-five experienced stabilization of previously progressive disease. Patients with responses and stable disease demonstrated markedly prolonged survival. Ranpirnase was well tolerated in the majority of patients, and there were no drug-related deaths. CONCLUSION Ranpirnase demonstrated activity and a tolerable toxicity profile in patients with unresectable MM. The prognostic value of the CALGB groups was confirmed.

Augmented HER-2–Specific Immunity during Treatment with Trastuzumab and Chemotherapy

Purpose: Passive immunotherapy with antitumor antibodies has the potential to induce active tumor immunity via the opsonic enhancement of immunogenicity of tumor antigen. We have assessed whether immune sensitization to the HER-2/neu tumor antigen occurs during treatment with the anti-HER-2/neu monoclonal antibody trastuzumab. Experimental Design: Twenty-seven patients treated with trastuzumab and chemotherapy were assessed for the induction of HER-2/neu–specific immunity. Sera and peripheral blood mononuclear cells obtained before and after trastuzumab therapy were compared for the presence of anti-HER-2/neu endogenous Igλ antibodies and HER-2/neu–specific CD4 responses by ELISA and enzyme-linked immunospot, respectively. Results: Anti-HER-2/neu antibodies were detectable in 8 of 27 (29%) patients before trastuzumab treatment and in 15 of 27 (56%) patients during trastuzumab treatment. In the overall study population, anti-HER-2/neu humoral responses significantly increased during therapy (P < 0.001) and were not associated with development of an anti-idiotypic response. In 10 evaluable individuals, 6 showed augmented HER-2/neu–specific CD4 T-cell responses during therapy. Of the 22 individuals treated for metastatic disease, those patients showing objective clinical responses exhibited more frequent (P = 0.004) and larger (P = 0.006) treatment-associated anti-HER-2/neu humoral responses. Conclusion: Humoral immune sensitization occurs during treatment with chemotherapy and trastuzumab. Further studies are warranted to investigate whether augmented anti-HER-2/neu humoral and cellular immunity contributes mechanistically to clinical outcome.

Multiepitope CD8+ T cell response to a NY-ESO-1 peptide vaccine results in imprecise tumor targeting

The cancer-testis antigen NY-ESO-1 is one of the most promising candidates for generic vaccination of cancer patients. Here we analyzed the CD8(+) T cell response to a NY-ESO-1 peptide vaccine composed of the two previously defined peptides 157-165 and 157-167, administered with GM-CSF as a systemic adjuvant. The NY-ESO-1 peptide vaccine elicited a CD8(+) T cell response directed against multiple distinct epitopes in the 157-167 region, as revealed by using A2/peptide multimers incorporating overlapping A2 binding peptides in this region. However, only a minor fraction of the elicited CD8(+) T cells, namely those recognizing the peptide 157-165 with sufficiently high functional avidity, recognized the naturally processed target on NY-ESO-1(+) tumor cells. In contrast, the majority of peptide 157-165-specific CD8(+) T cells exhibited lower functional avidity and no tumor reactivity. In addition, vaccine-elicited CD8(+) T cells specific for other overlapping epitopes in the 157-167 region failed to significantly recognize NY-ESO-1-expressing tumor targets. Thus, because of the complexity of the CD8(+) T cell repertoire that can be elicited by vaccination with synthetic peptides, a precise definition of the targeted epitope, and hence, of the corresponding peptide to be used as immunogen, is required to ensure a precise tumor targeting.

A multicenter phase II study of cisplatin, pemetrexed, and bevacizumab in patients with advanced malignant mesothelioma.

INTRODUCTION Malignant mesothelioma (MM) cells express the vascular endothelial growth factor (VEGF) receptor, and VEGF protein expression is detected in a majority of human mesothelioma biopsy specimens. Bevacizumab is a recombinant humanized monoclonal antibody that blocks the binding of VEGF to its receptor. We evaluated the addition of bevacizumab to cisplatin and pemetrexed as first-line treatment in patients with advanced, unresectable MM. METHODS Previously untreated MM patients with advanced, unresectable disease received cisplatin (75 mg/m(2)), pemetrexed (500 mg/m(2)), and bevacizumab (15 mg/kg) intravenously every 21 days for a maximum of 6 cycles. Patients with responsive or stable disease received bevacizumab (15 mg/kg) intravenously every 21 days until progression or intolerance. The primary endpoint was progression-free survival rate at 6 months. RESULTS 53 patients were enrolled at 4 centers; 52 were evaluable for this analysis. The progression-free survival rate at 6 months was 56% and the median progression-free survival was 6.9 months (95% confidence interval [CI], 5.3-7.8 months). The partial response rate was 40% and 35% of patients had stable disease. Median overall survival was 14.8 months (95% CI; 10.0-17.0 months). Grade 3/4 toxicities included neutropenia in 11%, hypertension in 6%, and venous thromboembolism in 13% of patients. CONCLUSION This trial evaluating the addition of bevacizumab to cisplatin and pemetrexed in patients with previously untreated, advanced MM failed to meet the primary endpoint of a 33% improvement in the progression-free survival rate at 6 months compared with historical controls treated with cisplatin and pemetrexed alone.

A phase II trial of temozolomide in patients with unresectable or metastatic soft tissue sarcoma

The objective of this study was to assess the efficacy and toxicity of the imidazotetrazine derivative temozolomide for patients with unresectable or metastatic soft tissue sarcoma.

Early Diagnosis of Relapse in Acute Myeloblastic Leukemia — Serologic Detection of Leukemia- Associated Antigens in Human Marrow

We tested serial bone-marrow samples from 47 adults with acute myeloblastic leukemia in remission for reactivity with heteroantiserums to leukemia-associated antigens, to determine whether imminent relapse could be detected in patients with acute leukemia. Of 26 patients who relapsed by standard morphologic criteria, 21 had increased immunoreactivity of bone marrow for one to six months (mean, 3.7 months) before relapse. High concordance was observed between a positive test and relapse during the period of study (chi-square = 27.53, P less than 0.001). The median time to relapse after a positive test was four months, as compared with the median remission duration of 19 months for the whole group (P less than 0.02, Petos log-rank analysis). Serologic detection of leukemia-associated antigens in marrow may be a reliable indicator of imminent relapse in acute myeloblastic leukemia.

Phase II trial of pemetrexed and gemcitabine in chemotherapy-naive malignant pleural mesothelioma.

PURPOSE Pemetrexed and gemcitabine have single-agent activity in malignant pleural mesothelioma (MPM). The combination of pemetrexed/gemcitabine has not previously been studied in MPM to our knowledge. PATIENTS AND METHODS Patients with histologic or cytologic diagnosis of MPM were included. Cohort 1 received gemcitabine 1,250 mg/m(2) on days 1 and 8, with pemetrexed 500 mg/m(2) on day 8, and cohort 2 received gemcitabine 1,250 mg/m(2) on days 1 and 8, with pemetrexed 500 mg/m(2) on day 1. Cycles were repeated every 21 days; all patients were supplemented with folic acid and vitamin B(12) and received dexamethasone. RESULTS One hundred eight patients (cohort 1, n = 56; cohort 2, n = 52) with pleural mesothelioma were enrolled. Among assessable patients, response rate was 26.0% in cohort 1 and 17.1% in cohort 2. Median time to disease progression was 4.34 months for cohort 1 and 7.43 months for cohort 2. Median survival was 8.08 months for cohort 1 (1-year survival = 31.14%) and 10.12 months for cohort 2 (1-year survival = 45.80%). In cohorts 1 and 2, incidence of grade 4 neutropenia was 25.0% and 29.4%, grade 4 thrombocytopenia was 14.3% and 3.9%, grade 3 or 4 anemia was 5.4% and 5.9%, and grade 3 or 4 fatigue was 23.2% and 15.7%, respectively. CONCLUSION The combination of pemetrexed and gemcitabine resulted in moderate clinical activity in MPM. However, the median survival times are similar to those with single-agent pemetrexed and inferior to outcomes observed with cisplatin in combination with an antifolate.

P16 Loss and Mitotic Activity Predict Poor Survival in Patients with Peritoneal Malignant Mesothelioma

Purpose: Peritoneal malignant mesothelioma is an aggressive neoplasm for which intensive therapy improves survival in a subset of patients. We hypothesized that pathologic variables would stratify patients into favorable and unfavorable survival subgroups. Experimental Design: Fifty-four patients with peritoneal malignant mesothelioma were evaluated for trimodal therapy from 1995 to 2003. Two pathologists evaluated pathologic variables independently, and p16 status was analyzed by immunohistochemistry. Results: Patients not receiving trimodal therapy had a significantly increased risk of death [hazard ratio (HR), 9.6; 4.3-21.6; P < 0.0001]. Biphasic histology was also associated with increased risk of death (HR, 8.5; 3.4-21.8; P < 0.0001). In multivariate analysis adjusting for treatment modality and histologic type, high mitotic rate and p16 loss were associated with increased risk of death (HR, 3.074; 1.05-9.0; P < 0.04 and HR, 3.65; 1.3-10.2; P < 0.014, respectively). Conclusions: Biphasic histology, increased mitotic rate, and p16 loss were independently associated with poorer survival in peritoneal malignant mesothelioma. Among the trimodal treated patients, increased mitotic rate was associated with increased risk of death.

PPARγ agonists enhance ET-743–induced adipogenic differentiation in a transgenic mouse model of myxoid round cell liposarcoma

Myxoid round cell liposarcoma (MRCLS) is a common liposarcoma subtype characterized by a translocation that results in the fusion protein TLS:CHOP as well as by mixed adipocytic histopathology. Both the etiology of MRCLS and the mechanism of action of TLS:CHOP remain poorly understood. It was previously shown that ET-743, an antitumor compound with an unclear mechanism of action, is highly effective in patients with MRCLS. To identify the cellular origin of MRCLS, we engineered a mouse model in which TLS:CHOP was expressed under the control of a mesodermally restricted promoter (Prx1) in a p53-depleted background. This model resembled MRCLS histologically as well as functionally in terms of its specific adipocytic differentiation-based response to ET-743. Specifically, endogenous mesenchymal stem cells (MSCs) expressing TLS:CHOP developed into MRCLS in vivo. Gene expression and microRNA analysis of these MSCs showed that they were committed to adipocytic differentiation, but unable to terminally differentiate. We also explored the method of action of ET-743. ET-743 downregulated TLS:CHOP expression, which correlated with CEBPα expression and adipocytic differentiation. Furthermore, PPARγ agonists enhanced the differentiation process initiated by ET-743. Our work highlights how clinical observations can lead to the generation of a mouse model that recapitulates human disease and may be used to develop rational treatment combinations, such as ET-743 plus PPARγ agonists, for the treatment of MRCLS.

Combined Resection, Intraperitoneal Chemotherapy, and Whole Abdominal Radiation for the Treatment of Malignant Peritoneal Mesothelioma

Objective:We report a single-institution Phase I or II trial of surgical debulking, intraperitoneal chemotherapy, and immunotherapy followed by whole abdominal radiotherapy in patients with malignant peritoneal mesothelioma. Methods:Between 1997 and 2000, 27 patients with malignant peritoneal mesothelioma were enrolled: 23 with epithelial subtype and 4 with sarcomatoid or mixed subtype. The treatment regimen consisted of surgical debulking followed by 4 intraperitoneal courses of cisplatin alternating with 4 courses of doxorubicin, 4 doses of intraperitoneal gamma interferon, a second laparotomy with resection of residual disease plus intraoperative intraperitoneal mitomycin and cisplatin heated to 41°C, and finally whole abdominal radiotherapy. Results:The median overall survival was 70 months with a 3-year survival of 67% (95% confidence interval, 46%–81%). Fourteen patients have died of their disease with a median time to death of 17 months (range, 0.4–71 months) after consenting to treatment. Seven patients are alive without evidence of disease with a median follow-up of 90 months (range, 71–110 months), and 6 are alive with disease with a median follow-up of 86 months (range, 70–106 months). The regimen was well tolerated. There were no patients with Grade III or IV hematological toxicities, 2 patients with Grade III ototoxicity, and 3 patients with Grade III gastrointestinal toxicity. Conclusion:Based on the results of this study, intensive multimodality therapy appears feasible and effective in this group of patients.