Daniel H. Sterman

A Live-Attenuated Listeria Vaccine (ANZ-100) and a Live-Attenuated Listeria Vaccine Expressing Mesothelin (CRS-207) for Advanced Cancers: Phase I Studies of Safety and Immune Induction

Purpose: Listeria monocytogenes (Lm)-based vaccines stimulate both innate and adaptive immunity. ANZ-100 is a live-attenuated Lm strain (Lm ΔactA/ΔinlB). Uptake by phagocytes in the liver results in local inflammatory responses and activation and recruitment of natural killer (NK) and T cells, in association with increased survival of mice bearing hepatic metastases. The Lm ΔactA/ΔinlB strain, engineered to express human mesothelin (CRS-207), a tumor-associated antigen expressed by a variety of tumors, induces mesothelin-specific T-cell responses against mesothelin-expressing murine tumors. These two phase I studies test ANZ-100 and CRS-207 in subjects with liver metastases and mesothelin-expressing cancers, respectively. Experimental Design: A single intravenous injection of ANZ-100 was evaluated in a dose escalation study in subjects with liver metastases. Nine subjects received 1 × 106, 3 × 107, or 3 × 108 colony-forming units (cfu). CRS-207 was evaluated in a dose-escalation study in subjects with mesothelioma, lung, pancreatic, or ovarian cancers. Seventeen subjects received up to 4 doses of 1 × 108, 3 × 108, 1 × 109, or 1 × 1010 cfu. Results: A single infusion of ANZ-100 was well tolerated to the maximum planned dose. Adverse events included transient laboratory abnormalities and symptoms associated with cytokine release. Multiple infusions of CRS-207 were well tolerated up to 1 × 109 cfu, the determined maximum tolerated dose. Immune activation was observed for both ANZ-100 and CRS-207 as measured by serum cytokine/chemokine levels and NK cell activation. In the CRS-207 study, listeriolysin O and mesothelin-specific T-cell responses were detected and 37% of subjects lived ≥15 months. Conclusions: ANZ-100 and CRS-207 administration was safe and resulted in immune activation. Clin Cancer Res; 18(3); 858–68. ©2011 AACR.

A Phase I Clinical Trial of Single-Dose Intrapleural IFN-β Gene Transfer for Malignant Pleural Mesothelioma and Metastatic Pleural Effusions: High Rate of Antitumor Immune Responses

Purpose: This phase 1 dose escalation study evaluated the safety and feasibility of single-dose intrapleural IFN-β gene transfer using an adenoviral vector (Ad.IFN-β) in patients with malignant pleural mesothelioma (MPM) and metastatic pleural effusions (MPE). Experimental Design: Ad.IFN-β was administered through an indwelling pleural catheter in doses ranging from 9 × 1011 to 3 × 1012 viral particles (vp) in two cohorts of patients with MPM (7 patients) and MPE (3 patients). Subjects were evaluated for (a) toxicity, (b) gene transfer, (c) humoral, cellular, and cytokine-mediated immune responses, and (d) tumor responses via 18-fluorodeoxyglucose-positron emission tomography scans and chest computed tomography scans. Results: Intrapleural Ad.IFN-β was generally well tolerated with transient lymphopenia as the most common side effect. The maximally tolerated dose achieved was 9 × 1011 vp secondary to idiosyncratic dose-limiting toxicities (hypoxia and liver function abnormalities) in two patients treated at 3 × 1012 vp. The presence of the vector did not elicit a marked cellular infiltrate in the pleural space. Intrapleural levels of cytokines were highly variable at baseline and after response to gene transfer. Gene transfer was documented in 7 of the 10 patients by demonstration of IFN-β message or protein. Antitumor immune responses were elicited in 7 of the 10 patients and included the detection of cytotoxic T cells (1 patient), activation of circulating natural killer cells (2 patients), and humoral responses to known (Simian virus 40 large T antigen and mesothelin) and unknown tumor antigens (7 patients). Four of 10 patients showed meaningful clinical responses defined as disease stability and/or regression on 18-fluorodeoxyglucose-positron emission tomography and computed tomography scans at day 60 after vector infusion. Conclusions: Intrapleural instillation of Ad.IFN-β is a potentially useful approach for the generation of antitumor immune responses in MPM and MPE patients and should be investigated further for overall clinical efficacy.

Bronchial thermoplasty: Long-term safety and effectiveness in patients with severe persistent asthma

BACKGROUND Bronchial thermoplasty (BT) has previously been shown to improve asthma control out to 2 years in patients with severe persistent asthma. OBJECTIVE We sought to assess the effectiveness and safety of BT in asthmatic patients 5 years after therapy. METHODS BT-treated subjects from the Asthma Intervention Research 2 trial (ClinicalTrials.govNCT01350414) were evaluated annually for 5 years to assess the long-term safety of BT and the durability of its treatment effect. Outcomes assessed after BT included severe exacerbations, adverse events, health care use, spirometric data, and high-resolution computed tomographic scans. RESULTS One hundred sixty-two (85.3%) of 190 BT-treated subjects from the Asthma Intervention Research 2 trial completed 5 years of follow-up. The proportion of subjects experiencing severe exacerbations and emergency department (ED) visits and the rates of events in each of years 1 to 5 remained low and were less than those observed in the 12 months before BT treatment (average 5-year reduction in proportions: 44% for exacerbations and 78% for ED visits). Respiratory adverse events and respiratory-related hospitalizations remained unchanged in years 2 through 5 compared with the first year after BT. Prebronchodilator FEV₁ values remained stable between years 1 and 5 after BT, despite a 18% reduction in average daily inhaled corticosteroid dose. High-resolution computed tomographic scans from baseline to 5 years after BT showed no structural abnormalities that could be attributed to BT. CONCLUSIONS These data demonstrate the 5-year durability of the benefits of BT with regard to both asthma control (based on maintained reduction in severe exacerbations and ED visits for respiratory symptoms) and safety. BT has become an important addition to our treatment armamentarium and should be considered for patients with severe persistent asthma who remain symptomatic despite taking inhaled corticosteroids and long-acting β₂-agonists.

Long-term Follow-up of Patients with Malignant Pleural Mesothelioma Receiving High-Dose Adenovirus Herpes Simplex Thymidine Kinase/Ganciclovir Suicide Gene Therapy

Purpose: Delineation of the long-term follow-up data on a series of patients with malignant mesothelioma, who received a single intrapleural dose of a nonreplicative adenoviral (Ad) vector encoding the herpes simplex virus thymidine kinase “suicide gene” (Ad.HSVtk) in combination with systemic ganciclovir. Experimental Design: This report focuses on the 21 patients receiving “high-dose” therapy, defined by an intrapleural dose of vector (≥1.6 × 1013 viral particles), where transgene-encoded tk protein was reliably identified on immunohistochemical staining. In 13 patients, the vector was deleted in the E1 and E3 regions of the Ad; in the other eight patients, the vector had deletions in the Ad genes E1 and E4. Safety, immunologic responses, transgene expression, and clinical responses were evaluated. Results: Both the E1/E3-deleted vector and the E1/E4-deleted vector were well tolerated and safe, although production of the E1/E4 vector was more difficult. Posttreatment antibody responses against the tumors were consistently seen. Interestingly, we observed a number of clinical responses in our patients, including two long-term (>6.5 year) survivors, both of whom were treated with the E1/E4-deleted vector. Conclusions: Intrapleural Ad.HSVtk/ganciclovir is safe and well tolerated in mesothelioma patients and resulted in long-term durable responses in two patients. Given the limited amount of gene transfer observed, we postulate that Ad.HSVtk may have been effective due to induction of antitumor immune responses. We hypothesize that approaches aiming to augment the immune effects of Ad gene transfer (i.e., with the use of cytokines) may lead to increased numbers of therapeutic responses in otherwise untreatable pleural malignancies.

A phase I study of Foscan-mediated photodynamic therapy and surgery in patients with mesothelioma

BACKGROUND Photodynamic therapy (PDT) is a light-based cancer treatment that, in the correct setting, can be delivered intraoperatively as an adjuvant therapy. A phase I clinical trial combining surgical debulking with Foscan-mediated PDT was performed in patients with malignant pleural mesothelioma. The purpose of the study was to define the toxicities and to determine the maximally tolerated dose (MTD) of Foscan-mediated PDT. METHODS A total of 26 patients completed treatment. Tumor debulking was accomplished with either an extrapleural pneumonectomy (7 patients) or a lung-sparing pleurectomy-decortication (19 patients). Patients were injected with Foscan before surgery, and 652 nm light was delivered intraoperatively after completion of surgical debulking. Four light sensors were placed in the chest, allowing delivery of light to a uniform measured dose throughout the hemithorax. RESULTS Four dose levels were explored. The MTD was 0.1 mg/kg of Foscan injected 6 days before surgery in combination with 10 J x cm(-2) 652 nm light. Dose limiting toxicity at the next higher dose was a systemic capillary leak syndrome leading to death in 2 of 3 patients treated at that dose. Other PDT-related toxicities included wound burns and skin photosensitivity. In all, 14 patients were treated at the MTD without significant complications. CONCLUSIONS Foscan-mediated PDT can be safely combined with surgery at the established MTD. Unlike most other surgery-based multimodal treatments for mesothelioma, Foscan-mediated PDT affords the option, in selected patients, of accomplishing tumor debulking with a lung-sparing procedure rather than an extrapleural pneumonectomy. A phase II study is warranted.

Outpatient Management of Malignant Pleural Effusions with Small-Bore, Tunneled Pleural Catheters

Background: Malignant pleural effusions (MPEs) can produce significant respiratory symptoms and diminished quality of life in patients with terminal malignancies. Control of MPEs to palliate respiratory symptoms can be performed via several different approaches. Ideally, a minimally invasive procedure to control MPEs and to provide relief of respiratory symptoms would be optimal. Objective: To ascertain if control of MPEs can be achieved by outpatient management via a small-bore pleural catheter (PC) without the need for sclerosing agents. Methods: Retrospective chart analysis of 24 patients after outpatient insertion of PCs for recurrent, symptomatic MPEs followed by frequent home drainage of pleural fluid to relieve respiratory symptoms. Results: Symptomatic relief of respiratory symptoms was achieved in 100% of patients, while pleurodesis was achieved in 58% of patients in a mean of 39 days. Five patients (6 PCs) expired with the catheters in place. In these patients, all catheters remained in position and functional until the patients ultimately died from nonpleural disease progression. No major complications occurred during insertion of the catheter. Late complications included localized cellulitis and bacterial superinfection in three patients and tumor growth at the catheter site in one patient. Conclusions: The PCs used in the present study provided an effective modality not only to alleviate respiratory symptoms associated with MPE, but also to achieve pleurodesis in 58% of our patients. These catheters may provide a significantly less invasive outpatient approach to the palliative management of MPEs.

A Multicenter Pilot Study of a Bronchial Valve for the Treatment of Severe Emphysema

Background: Chronic obstructive pulmonary disease (COPD) affects millions of people and has limited treatment options. Surgical treatments for severe COPD with emphysema are effective for highly selected patients. A minimally invasive method for treating emphysema could decrease morbidity and increase acceptance by patients. Objective: To study the safety and effectiveness of the IBV® Valve for the treatment of severe emphysema. Methods: A multicenter study treated 91 patients with severe obstruction, hyperinflation and upper lobe (UL)-predominant emphysema with 609 bronchial valves placed bilaterally into ULs. Results: Valves were placed in desired airways with 99.7% technical success and no migration or erosion. There were no procedure-related deaths and 30-day morbidity and mortality were 5.5 and 1.1%, respectively. Pneumothorax was the most frequent serious device-related complication and primarily occurred when all segments of a lobe, especially the left UL, were occluded. Highly significant health-related quality of life (HRQL) improvement (–8.2 ± 16.2, mean ± SD change at 6 months) was observed. HRQL improvement was associated with a decreased volume (mean –294 ± 427 ml, p = 0.007) in the treated lobes without visible atelectasis. FEV1, exercise tests, and total lung volume were not changed but there was a proportional shift, a redirection of inspired volume to the untreated lobes. Combined with perfusion scan changes, this suggests that there is improved ventilation and perfusion matching in non-UL lung parenchyma. Conclusion: Bronchial valve treatment of emphysema has multiple mechanisms of action and acceptable safety, and significantly improves quality of life for the majority of patients.

A Phase I Trial of Repeated Intrapleural Adenoviral-mediated Interferon-β Gene Transfer for Mesothelioma and Metastatic Pleural Effusions

We previously showed that a single intrapleural dose of an adenoviral vector expressing interferon-β (Ad.IFN-β) in patients with malignant pleural mesothelioma (MPM) or malignant pleural effusions (MPE) resulted in gene transfer, humoral antitumor immune responses, and anecdotal clinical responses manifested by modified Response Evaluation Criteria in Solid Tumors (RECIST) disease stability in 3 of 10 patients at 2 months and an additional patient with significant metabolic response on positron emission tomography (PET) imaging. This phase I trial was conducted to determine whether using two doses of Ad.IFN-β vector would be superior. Ten patients with MPM and seven with MPE received two doses of Ad.IFN-β through an indwelling pleural catheter. Repeated doses were generally well tolerated. High levels of IFN-β were detected in pleural fluid after the first dose; however, only minimal levels were seen after the second dose of vector. Lack of expression correlated with the rapid induction of neutralizing Ad antibodies (Nabs). Antibody responses against tumor antigens were induced in most patients. At 2 months, modified RECIST responses were as follows: one partial response, two stable disease, nine progressive disease, and two nonmeasurable disease. One patient died after 1 month. By PET scanning, 2 patients had mixed responses and 11 had stable disease. There were seven patients with survival times longer than 18 months. This approach was safe, induced immune responses and disease stability. However, rapid development of Nabs prevented effective gene transfer after the second dose, even with a dose interval as short as 7 days.We previously showed that a single intrapleural dose of an adenoviral vector expressing interferon-beta (Ad.IFN-beta) in patients with malignant pleural mesothelioma (MPM) or malignant pleural effusions (MPE) resulted in gene transfer, humoral antitumor immune responses, and anecdotal clinical responses manifested by modified Response Evaluation Criteria in Solid Tumors (RECIST) disease stability in 3 of 10 patients at 2 months and an additional patient with significant metabolic response on positron emission tomography (PET) imaging. This phase I trial was conducted to determine whether using two doses of Ad.IFN-beta vector would be superior. Ten patients with MPM and seven with MPE received two doses of Ad.IFN-beta through an indwelling pleural catheter. Repeated doses were generally well tolerated. High levels of IFN-beta were detected in pleural fluid after the first dose; however, only minimal levels were seen after the second dose of vector. Lack of expression correlated with the rapid induction of neutralizing Ad antibodies (Nabs). Antibody responses against tumor antigens were induced in most patients. At 2 months, modified RECIST responses were as follows: one partial response, two stable disease, nine progressive disease, and two nonmeasurable disease. One patient died after 1 month. By PET scanning, 2 patients had mixed responses and 11 had stable disease. There were seven patients with survival times longer than 18 months. This approach was safe, induced immune responses and disease stability. However, rapid development of Nabs prevented effective gene transfer after the second dose, even with a dose interval as short as 7 days.

Radical pleurectomy and intraoperative photodynamic therapy for malignant pleural mesothelioma.

BACKGROUND Radical pleurectomy (RP) for mesothelioma is often considered either technically unfeasible or an operation limited to patients who would not tolerate a pneumonectomy. The purpose of this study was to review our experience using RP and intraoperative photodynamic therapy (PDT) for mesothelioma. METHODS Thirty-eight patients (42-81 years) underwent RP-PDT. Thirty five of 38 (92%) patients also received systemic therapy. Standard statistical techniques were used for analysis. RESULTS Thirty seven of 38 (97%) patients had stage III/IV cancer (according to the American Joint Committee on Cancer [AJCC manual 7th Edition, 2010]) and 7/38 (18%) patients had nonepithelial subtypes. Macroscopic complete resection was achieved in 37/38 (97%) patients. There was 1 postoperative mortality (stroke). At a median follow-up of 34.4 months, the median survival was 31.7 months for all 38 patients, 41.2 months for the 31/38 (82%) patients with epithelial subtypes, and 6.8 months for the 7/38 (18%) patients with nonepithelial subtypes. Median progression-free survival (PFS) was 9.6, 15.1, and 4.8 months, respectively. The median survival and PFS for the 20/31 (64%) patients with N2 epithelial disease were 31.7 and 15.1 months, respectively. CONCLUSIONS It was possible to achieve a macroscopic complete resection using lung-sparing surgery in 97% of these patients with stage III/IV disease. The survival we observed with this approach was unusually long for the patients with the epithelial subtype but, interestingly, the PFS was not. The reason for this prolonged survival despite recurrence is not clear but is potentially related to preservation of the lung or some PDT-induced effect, or both. We conclude that the results of this lung-sparing approach are safe, encouraging, and warrant further investigation.

Advances in the diagnosis, evaluation, and management of malignant pleural mesothelioma

Abstract:  Malignant mesothelioma is an insidious neoplasm arising from the mesothelial surfaces of the pleural and peritoneal cavities, the pericardium, or the tunica vaginalis. A total of 80% of all cases are pleural in origin. The predominant cause of malignant mesothelioma is inhalational exposure to asbestos, although evidence is increasing to support the hypothesis that simian virus−40 virus plays a role in cocarcinogenesis. Immunohistochemical markers such as calretinin, WT‐1, and cytokeratin 5/6 are becoming established diagnostic markers. Preliminary data suggests that a soluble form of mesothelin could serve as a serum marker for established and early cases of mesothelioma. Positron emission tomography with 18‐fluorodeoxyglucose in conjunction with computed tomograhy scanning has improved preoperative imaging and staging. Prognostic factors have been identified and verified. Negative indicators include thrombocytosis, high leukocyte counts, poor performance status, and nonepithelial histology. For the first time, there is now evidence that some treatments are increasing the quality and quantity of life for patients with mesothelioma. Chemotherapy, with the new multitargeted antifolate drug Pemetrexed, combined with cisplatin, has shown superior survival rates in a large phase III trial when compared to cisplatin alone. High‐dose intensity‐modulated radiotherapy when administered after extrapleural pneumonectomy has resulted in excellent local control. Multimodality treatment programs that combine surgical cytoreduction with novel forms of radiation therapy and more effective chemotherapy combinations may offer significant increases in survival for certain subgroups of mesothelioma patients. Innovative palliative approaches have proved successful in alleviation of the significant symptoms experienced by many mesothelioma patients. Experimental treatments such as immunotherapy and gene therapy present a window of hope for all mesothelioma patients, and in the future, may be combined with ‘standard therapy’ in multimodality protocols. Patients with adequate performance status should be enrolled into clinical trials where possible. Over the past decade, significant advances have been made on several fronts that have improved the ability to diagnose a stage, define prognosis, and treat malignant pleural mesothelioma.