Population Pharmacokinetics and Exposure-Response Analysis for the CTLA-4 Inhibitor Tremelimumab in Metastatic NSCLC Patients in the Phase III POSEIDON Study

Blockade of CTLA-4 by tremelimumab combined with anti-PD-L1 durvalumab and chemotherapy provided increased antitumor activity and long-term survival benefits in first-line metastatic non-small cell lung cancer (mNSCLC) in the phase III POSEIDON study. We performed population pharmacokinetic modeling for tremelimumab using data from 1,605 patients across 6 studies (including POSEIDON) in multiple tumors (lung cancer, bladder cancer, malignant mesothelioma, and other solid tumors), and identified a 2-compartment model with linear and time-varying clearance for tremelimumab. Cox proportional hazard regression models were applied to 326 patients with mNSCLC from POSEIDON to evaluate the association between exposure metrics and efficacy end points, adjusting for baseline prognostic covariates. Improved progression-free survival (PFS) and overall survival (OS) in the tremelimumab arm (in combination with durvalumab and chemotherapy) was associated with higher tremelimumab exposure (e.g., minimum concentration at 5th dose (Cmin,dose5 ) and area under the curve at 5th dose (AUCdose5 )). However, further case-matching analyses yielded hazard ratios for the comparison of tremelimumab-treated patients in the Cmin,dose5 quartile 1 (Q1) subgroup with matched chemotherapy-treated patients of 1.04 (95% confidence interval (CI): 0.76-1.44) for OS and 0.99 (95% CI: 0.72-1.36) for PFS, suggesting that the observed apparent exposure-response relationship might be confounded. No relationship between tremelimumab exposure and safety (grade ≥3 treatment-emergent adverse events [AEs], AEs of special interest, or discontinuation due to AEs) was identified. These results support the consistent benefit observed with tremelimumab 75 mg every 3 weeks for up to 5 doses in combination with durvalumab and chemotherapy in POSEIDON as first-line therapy for mNSCLC.

Population pharmacokinetic modelling of tremelimumab in patients with advanced solid tumours and the impact of disease status on time-varying clearance

AIMS

Tremelimumab, a cytotoxic T-lymphocyte-associated protein 4 human monoclonal antibody of the immunoglobulin G2 κ isotype, has been studied in oncology clinical trials as both monotherapy and in combination with durvalumab. This study characterized the pharmacokinetics of tremelimumab as monotherapy and in combination with durvalumab and evaluated the impact of patient covariates on pharmacokinetics.

METHODS

A pooled-analysis population pharmacokinetics model was built using NONMEM methodology. Pharmacokinetic data from 5 studies spanning different tumour types and therapy regimens were pooled for model development (956 patients). A dataset pooled from 4 additional studies was used for external validation (554 patients). Demographic and relevant clinical covariates were explored during model development.

RESULTS

Tremelimumab exhibited linear pharmacokinetics, well described by a 2-compartment model, with time-varying clearance (0.276 L/day at baseline) associated primarily with therapy regimen and linked with changes in disease status. As monotherapy and combination therapy, tremelimumab clearance over 1 year increased by ~16% and decreased by ~17%, respectively. Pharmacokinetic behaviour was consistent across patient demographics and cancer subtypes. Patients with higher bodyweight and lower albumin levels at baseline had significantly higher clearance; however, no dosage adjustments are warranted. A flat dose (75 mg) was projected to provide comparable exposure to weight-based dosing (1 mg/kg) in adults.

CONCLUSION

Tremelimumab exhibited linear pharmacokinetics but consistently opposite trends of time-varying clearance as monotherapy and in combination with durvalumab. Baseline bodyweight and albumin were significant covariates, but conversion from weight-based dosing at 1 mg/kg to flat dosing at 75 mg had no clinically relevant impact.

Real-World Clinical Impact of Immune Checkpoint Inhibitors in Patients With Advanced/Metastatic Non-Small Cell Lung Cancer After Platinum Chemotherapy

BACKGROUND

The real-world effect of anti-programmed death ligand 1 (PD-L1) therapies is unclear. We compared US patients who received second-line therapy for non-small-cell lung cancer (NSCLC) before and shortly after US Food and Drug Administration (FDA) approval of PD-L1 inhibitors.

PATIENTS AND METHODS

Patients in the Flatiron Health database (≥18 years; received first-line platinum therapy for advanced/metastatic NSCLC; ≥6 months of follow-up) were assessed before ("historical": January 1, 2011 to December 31, 2013) and after ("current": January 1, 2015 to May 31, 2017) FDA approval of anti-PD-L1 therapies for NSCLC. Index was start of second-line therapy. Baseline variables, treatment patterns, and overall survival (OS) were reported.

RESULTS

A greater proportion of patients in the current cohort received second-line treatment than in the historical cohort (n = 4240 [57.0%] vs. n = 2357 [37.4%]); 48.8% [n = 2071] of the current second-line patients received anti-PD-L1 therapy. Current patients were more likely to receive second-line anti-PD-L1 therapy if they had poorer Eastern Cooperative Oncology Group (ECOG) performance status (≥2), had squamous histology, or had no epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), or ROS proto-oncogene 1 mutations. Median OS from index was higher in the current cohort (9.4 [95% confidence interval (CI), 8.9-9.9] months) than the historical cohort (7.3 [95% CI, 6.9-7.8] months). Adjusted for sex, race, ECOG performance status, disease stage, and Kirsten rat sarcoma viral oncogene homolog, EGFR, and ALK status, OS was improved by 15% in the current cohort.

CONCLUSION

Contemporary patients are more likely to receive second-line therapy and have longer OS than patients who received care before approval of anti-PD-L1 therapies.

Patterns of failure in limited-stage small cell lung cancer: Implications of TNM stage for prophylactic cranial irradiation

BACKGROUND AND PURPOSE

The relationship between tumor-node-metastasis (TNM) stage and patterns of failure in limited-stage small cell lung cancer (LS-SCLC) remains unclear. We hypothesized that TNM stage predicts brain metastasis risk, and could inform the use of prophylactic cranial irradiation.

MATERIAL AND METHODS

We reviewed 283 patients with stage I-IIIB SCLC. Competing-risks regression was used to analyze local, distant, and brain failure. Multivariate analysis was used to evaluate the effect of treatment and clinical factors on failure and OS.

RESULTS

Patients with stage I or II SCLC (35% of cohort) had significantly better survival and lower risk of distant and brain metastasis, compared with stage III patients. The 5-year cumulative incidence of brain metastasis for stage I/II and III were 12% and 26%, respectively. Stage had no correlation with local failure. On multivariate analysis, stage was independently prognostic for survival, distant metastasis risk, and brain metastasis risk.

CONCLUSIONS

TNM staging predicts likelihood of distant metastasis, brain metastasis, and survival in LS-SCLC. This supports the routine use of TNM staging in clinical practice. The lower risk of brain metastasis in stage I and II SCLC suggests that prophylactic cranial irradiation could play a more limited role in treatment of early-stage disease.

Abstract CT070: A open-label phase 3b/4 safety trial of flat-dose nivolumab in combination with ipilimumab in patients with advanced non-small cell lung cancer (NSCLC)

Background: Nivolumab and ipilimumab are immune checkpoint inhibitor antibodies with distinct but complementary mechanisms of action, and their combination may improve clinical outcomes compared with single-agent therapy. Nivolumab plus ipilimumab is approved for the first-line treatment of metastatic melanoma and has shown encouraging clinical activity in other tumor types, including NSCLC. In CheckMate 012, a multi-cohort phase 1 trial that evaluated nivolumab as monotherapy or in combination with other agents in chemotherapy-naïve patients with NSCLC, weight-based administration of nivolumab (3 mg/kg) plus ipilimumab (1 mg/kg) yielded objective response rates (ORR) of up to 47%, depending on the dosing schedule. The discontinuation rates attributable to treatment-related adverse events (AEs) in patients treated with nivolumab plus ipilimumab were similar to nivolumab monotherapy, and AEs were consistent with the known safety profiles of the individual agents. Pharmacokinetic, safety, and efficacy data indicate comparable safety and efficacy profiles for 240 mg flat-dose nivolumab and 3 mg/kg nivolumab. This open-label phase 3b/4 study (ClinicalTrials.gov identifier: NCT02869789) will characterize the safety of flat-dose nivolumab combined with ipilimumab in patients with advanced NSCLC. Moreover, this study will evaluate this combination in special patient populations that are typically excluded from NSCLC trials.

Methods: Adult patients with stage IV/recurrent NSCLC and no prior systemic anticancer therapy, including epidermal growth factor receptor and anaplastic lymphoma kinase inhibitors (cohort A), or with stage IIIb/IV NSCLC and recurrence or progression during or after one prior platinum doublet chemotherapy regimen (cohort B) will be enrolled, with a planned sample size of 400 patients per cohort. Patients are required to have assessment of programmed death-1 ligand 1 expression, Eastern Cooperative Oncology Group performance status (ECOG PS) 0–1, and no untreated brain metastases, carcinomatous meningitis, autoimmune disease, or active malignancy requiring concurrent intervention. A third cohort (A1) of approximately 200 patients with no prior systemic therapy will have either ECOG PS 2 or one or more of the following: asymptomatic untreated brain metastases, renal or hepatic dysfunction, and/or HIV. All patients will receive flat-dose nivolumab (240 mg every 2 weeks) combined with weight-based ipilimumab (1 mg/kg every 6 weeks). The primary endpoint is a descriptive assessment of the number and percentage of patients with high-grade treatment-related select and immune-mediated AEs in cohorts A and B. Secondary efficacy endpoints include progression-free survival, ORR, duration of response, and patient-reported outcomes based on the Functional Assessment of Cancer Therapy-Lung (FACT-L).

Citation Format: Rathi N. Pillai, Bradley Lash, Istvan Albert, Gabrielle Gagnon, Carl Chakmakjian, Neal Ready, Wenhua Hu, Lee Krug, Sutapa Mukhopadhyay, Luis Paz-Ares. A open-label phase 3b/4 safety trial of flat-dose nivolumab in combination with ipilimumab in patients with advanced non-small cell lung cancer (NSCLC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT070. doi:10.1158/1538-7445.AM2017-CT070

The IASLC Mesothelioma Staging Project: Proposals for the M Descriptors and for Revision of the TNM Stage Groupings in the Forthcoming (Eighth) Edition of the TNM Classification for Mesothelioma

INTRODUCTION

The M component and TNM stage groupings for malignant pleural mesothelioma (MPM) have been empirical. The International Association for the Study of Lung Cancer developed a multinational database to propose evidence-based revisions for the eighth edition of the TNM classification of MPM.

METHODS

Data from 29 centers were submitted either electronically or by transfer of existing institutional databases. The M component as it currently stands was validated by confirming sufficient discrimination (by Kaplan-Meier analysis) with respect to overall survival (OS) between the clinical M0 (cM0) and cM1 categories. Candidate stage groups were developed by using a recursive partitioning and amalgamation algorithm applied to all cM0 cases.

RESULTS

Of 3519 submitted cases, 2414 were analyzable and 84 were cM1 cases. Median OS for cM1 cases was 9.7 months versus 13.4 months (p = 0.0013) for the locally advanced (T4 or N3) cM0 cases, supporting inclusion of only cM1 in the stage IV group. Exploratory analyses suggest a possible difference in OS for single- versus multiple-site cM1 cases. A recursive partitioning and amalgamation-generated survival tree on the OS outcomes restricted to cM0 cases with the newly proposed (eighth edition) T and N components indicates that optimal stage groupings for the eighth edition will be as follows: stage IA (T1N0), stage IB (T2-3N0), stage II (T1-2N1), stage IIIA (T3N1), stage IIIB (T1-3N2 or any T4), and stage IV (any M1).

CONCLUSIONS

This first evidence-based revision of the TNM classification for MPM leads to substantial changes in the T and N components and the stage groupings.

The IASLC Mesothelioma Staging Project: Proposals for Revisions of the T Descriptors in the Forthcoming Eighth Edition of the TNM Classification for Pleural Mesothelioma

INTRODUCTION

The current T component for malignant pleural mesothelioma (MPM) has been predominantly informed by surgical data sets and consensus. The International Association for the Study of Lung Cancer undertook revision of the seventh edition of the staging system for MPM with the goal of developing recommendations for the eighth edition.

METHODS

Data elements including detailed T descriptors were developed by consensus. Tumor thickness at three pleural levels was also recorded. An electronic data capture system was established to facilitate data submission.

RESULTS

A total of 3519 cases were submitted to the database. Of those eligible for T-component analysis, 509 cases had only clinical staging, 836 cases had only surgical staging, and 642 cases had both available. Survival was examined for T categories according to the current seventh edition staging system. There was clear separation between all clinically staged categories except T1a versus T1b (hazard ratio = 0.99, p = 0.95) and T3 versus T4 (hazard ratio = 1.22, p = 0.09), although the numbers of T4 cases were small. Pathological staging failed to demonstrate a survival difference between adjacent categories with the exception of T3 versus T4. Performance improved with collapse of T1a and T1b into a single T1 category; no current descriptors were shifted or eliminated. Tumor thickness and nodular or rindlike morphology were significantly associated with survival.

CONCLUSIONS

A recommendation to collapse both clinical and pathological T1a and T1b into a T1 classification will be made for the eighth edition staging system. Simple measurement of pleural thickness has prognostic significance and should be examined further with a view to incorporation into future staging.

The International Association for the Study of Lung Cancer Lung Cancer Staging Project: Proposals for the Revision of the Clinical and Pathologic Staging of Small Cell Lung Cancer in the Forthcoming Eighth Edition of the TNM Classification for Lung Cancer

INTRODUCTION

Small cell lung cancer (SCLC) is commonly classified as either limited or extensive, but the Union for International Cancer Control TNM Classification of Malignant Tumours seventh edition (2009) recommended tumor, node, and metastasis (TNM) staging based on analysis of the International Association for the Study of Lung Cancer (IASLC) database.

METHODS

Survival analyses were performed for clinically and pathologically staged patients presenting with SCLC from 1999 through 2010. Prognosis was compared in relation to the TNM seventh edition staging to serve as validation and analyzed in relation to proposed changes to the T descriptors found in the eighth edition.

RESULTS

There were 5002 patients: 4848 patients with clinical and 582 with pathological stages. Among these, 428 had both. Survival differences were confirmed for T and N categories and maintained in relation to proposed revisions to T descriptors for seventh edition TNM categories and proposed changes in the eighth edition. There were also survival differences, notably at 12 months, in patients with brain-only single-site metastasis (SSM) compared to SSM at other sites, and SSM without a pleural effusion showed a better prognosis than other patients in the M1b category.

CONCLUSION

We confirm the prognostic value of clinical and pathological TNM staging in patients with SCLC, and recommend continued usage for SCLC in relation to proposed changes to T, N, and M descriptors for NSCLC in the eighth edition. However, for M descriptors, it remains uncertain whether survival differences in patients with SSM in the brain simply reflect better treatment options rather than better survival based on anatomic extent of disease.

Activation of transposable elements during aging and neuronal decline in Drosophila

We found that several transposable elements were highly active in Drosophila brain during normal aging. In addition, we found that mutations in Drosophila Argonaute 2 (Ago2) resulted in exacerbated transposon expression in the brain, progressive and age-dependent memory impairment, and shortened lifespan. These findings suggest that transposon activation may contribute to age-dependent loss of neuronal function.

A phase II study of sorafenib in malignant mesothelioma: results of Cancer and Leukemia Group B 30307

HYPOTHESIS

Malignant mesotheliomas (MMs) express vascular endothelial growth factor receptor (VEGFR), platelet-derived growth factor receptor, and cKIT. Sorafenib is a potent inhibitor of the ras/raf/MEK pathway and also targets VEGFR and cKIT. We evaluated the activity of sorafenib in patients with unresectable mesothelioma.

METHODS

MM patients who had received 0 to 1 prior chemotherapy regimens were treated with sorafenib 400 mg orally twice daily continuously. The primary end point was objective response. ERK1/2 phosphorylation in archival tissues was correlated with response and survival.

RESULTS

A total of 51 patients were enrolled, 50 were evaluable and included in the analysis. Three patients had a partial response (6% [95% confidence interval = 1.3-16.6%]), and 27 (54% [95% confidence interval = 39.3-68.2%]) had stable disease. Median progression-free survival and median overall survival (OS) were 3.6 and 9.7 months, respectively. Median survival was superior in epithelioid histology versus other types (10.7 versus 3.7 months, p = 0.0179). The difference in median OS between pretreated and chemonaive patients was not statistically significant (13.2 versus 5 months, p = 0.3117). Low/negative baseline tumor phospho-ERK1/2 levels were associated with improved OS (13.9 versus 5.2 months, p = 0.0066).

CONCLUSION

Sorafenib has limited activity in advanced MM patients, similar to that seen with other VEGFR tyrosine kinase inhibitors. Additional studies of sorafenib in MM are not warranted.

Frequency of use and outcome of surgical resection in the management of malignant mesothelioma in a community-based population: Results in 5,937 patients

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Background: Multimodality therapy of mesothelioma patients treated at specialized tertiary hospitals report surgical resection rates of 42% (Flores RM et al. Prognostic Factors in the Treatment of Malignant Pleural Mesothelioma at a Large Tertiary Referral Center. J Thorac Oncol 2007;2(10):957–965.). Treatment strategies in the community are less well defined and surgical expertise is not readily available. We undertook this study to evaluate the rate of surgical resection and its association with survival in a non-tertiary based population. Methods: The Surveillance, Epidemiology, and End Results (SEER) database was searched from 1990 - 2004. Variables analyzed included age, sex, race, year of diagnosis, laterality, vital status, stage, surgery, and reasons for no surgery. The association of resection on overall survival was estimated by the Kaplan-Meier method and examined in a Cox proportional hazards model adjusting for covariates. Results: Pathologically proven malignant pleural mesothelioma was identified in 5,937 patients: 1,166 women, 4,771 men; median age was 70 years. Surgical resection rate was 11% (n=636). Univariate analysis demonstrated a median survival of 13 months with surgical resection and a median survival of 7 months in the non-resected group (p<0.0001). Multivariate analysis demonstrated improved survival for surgically resected patients (HR 0.7, p<0.0001), controlling for age, gender, and stage. Conclusions: Surgical resection was associated with improved survival when controlling for age, stage, and gender. However, the rate of surgical resection was much lower in the community when compared to tertiary referral centers. Treatment efforts should be focused on a multidisciplinary approach which includes surgical evaluation.

No significant financial relationships to disclose.

Prognostic factors in the treatment of malignant pleural mesothelioma at a large tertiary referral center

INTRODUCTION

Most studies describing the natural history and prognostic factors for malignant pleural mesothelioma antedate accurate pathologic diagnosis, staging by computed tomography, and a universal staging system. We conducted a large single-institution analysis to identify prognostic factors and assess the association of resection with outcome in a contemporary patient population.

METHODS

Patients with biopsy-proven malignant pleural mesothelioma at our institution were identified and clinical data were obtained from an institutional database. Survival and prognostic factors were analyzed by the Kaplan-Meier method, log-rank test, and Cox proportional hazards analysis. A p value <0.05 was considered statistically significant.

RESULTS

From 1990 to 2005, 945 patients were identified: 755 men, 190 women; median age, 66 years (range, 26-93). Extrapleural pneumonectomy was performed in 208 (22%), pleurectomy/decortication in 176 (19%). Operative mortality was 4% (16/384). Multimodality therapy including surgery was associated with a median survival of 20.1 months. Significant predictors of overall survival included histology, gender, smoking, asbestos exposure, laterality, surgical resection by extrapleural pneumonectomy or pleurectomy/decortication, American Joint Committee on Cancer stage, and symptoms. A Cox model demonstrated a hazard ratio of 1.4 without surgical resection when controlling for histology, stage, gender, asbestos exposure, smoking history, symptoms, and laterality (p = 0.003).

CONCLUSIONS

In addition to tumor histology and pathologic stage, predictors of survival include gender, asbestos exposure, smoking, symptoms, laterality, and clinical stage. Surgical resection in a multimodality setting was associated with improved survival.

Single agent bevacizumab and bevacizumab in combination with docetaxel and cisplatin as induction therapy for resectable IB-IIIA non-small cell lung cancer

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Background: Bevacizumab (Bev) improves response and survival in patients with advanced non-squamous lung cancer with chemotherapy however there are limited data as single agent therapy and in early stage NSCLC. Methods: Patients with resectable stage IB-IIIA NSCLC were eligible. Patients with adenocarcinoma (Cohort 1) received preoperative Bev and docetaxel and cisplatin (DC). Patients with squamous histology, central location or recent hemoptysis received DC induction therapy without Bev (Cohort 2). Cohort 1 received Bev (15 mg/kg) followed by CT 2 weeks later to assess single agent Bev response. Subsequently D (75 mg/m2) and C (75 mg/m2) were given q 3 weeks; an additional 2 cycles of Bev was administered with C2 and C3 of DC (total of 3 preoperative doses of Bev). Cohort 2 received DC alone followed by resection. Both cohorts received adjuvant Bev x 1 year. Study endpoints included response to single agent Bev, downstaging, safety and survival. Results: 19 patients of planned 70 were enrolled (11 Cohort 1 and 8 Cohort 2). On Cohort 1, there were 2 clinical stage IIB and 9 IIIA patients. After single agent Bev (by bimensional measurement), > 10% reduction in tumor size was observed after 2 weeks in 6/11 patients (- 20%, 15%, 16%, 15%, 13% and 20%). After Bev + DC, there were 6/10 (60%) PRs and DC delivery was 96%. 6/10 patient underwent R0 resection; 1 R2 and 2 were unresectable. 1 patient developed hemoptysis preoperatively and 1 patient developed an upper GI bleed post-operatively. There were otherwise no Bev related operative complications observed. 5/9 patients were downstaged by induction treatment. 3 patients received adjuvant bevacizumab to date (median 5.7 cycles). 8 patients were treated on Cohort 2 (3 with stage IB, 1 with IIB and 4 with IIIA). All 8 patients underwent R0 resection. DC delivery was 94% and there were 6/8 PRs. Downstaging was observed in 5/8 patients and 6/8 are receiving adjuvant Bev (median # cycles to date = 6.7). Conclusions: Bev as a single agent demonstrates regression of tumors after 2 weeks. To date, Bev has been safely administered in the neoadjuvant and adjuvant setting. Preoperative chemotherapy is well tolerated with more than 90% full dose drug delivery. The study is ongoing. Supported by Genentech, Inc.

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Phase I study of the antifolate pralatrexate given with vitamin B12 and folic acid supplementation in patients (pts) with advanced non-small cell lung cancer (NSCLC)

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Background: Pralatrexate is a novel antifolate that has shown promising activity in the treatment of pts with previously- treated NSCLC at doses of 135–150 mg/m2 IV every other week (q2w). [Krug, Clin Cancer Res 9(6), 2003; 6(9), 2000] The addition of vitamin B12 and folic acid supplementation may mitigate toxicity from pralatrexate and improve efficacy by allowing higher doses to be delivered. Methods: This study is designed to determine the maximum tolerated dose (MTD) of pralatrexate in combination with vitamin B12 and folic acid supplementation in pts with NSCLC. Key eligibility criteria include confirmed stage IIIB or IV NSCLC; at least 1 prior chemotherapy regimen; Karnofsky performance status (KPS) = 70%; and no other active concurrent malignancy. Using a rapid escalation design, pralatrexate was initially administered at a dose of 150 mg/m2 IV q2w, escalating by 40 mg/m2 increments in successive cohorts, with one patient per cohort if no dose limiting toxicity (DLT) is encountered. All pts receive vitamin B12 1 mg intramuscular q 8–10 weeks and folic acid 1 mg by mouth once a day beginning at least 7 days prior to pralatrexate. All patients undergo pharmacokinetic testing following their first and second dose of pralatrexate. Results: Between 1/05–12/06, a total of 9 pts have been treated at the following dose levels: 150 (n=1), 190 (n=1), 230 (n=1), and 270 (n=6). Patient characteristics include: 2 male/7 female; median age 63 (range 52–73); KPS 80–90%; all pts had stage 4 NSCLC; 5 pts received 1 prior regimen and 4 pts received 2 or more prior regimens. Grade 3 esophagitis was a DLT in one patient at the 270 mg/m2 dose. Three other patients experienced grade 1–2 mucositis at this dose level without limiting drug delivery. The trial is ongoing, and enrollment is planned at 310 mg/m2 q2w to determine the MTD. Conclusions: When given in combination with vitamin B12 and folic acid supplementation, pralatrexate has been well tolerated in this pt population, with an MTD at least twice as high as achieved in previous phase 1 testing without supplementation. We plan to conduct a phase 2 trial of pralatrexate with vitamin B12 and folic acid supplementation to see if a higher dose will improve efficacy.

No significant financial relationships to disclose.

Efficacy of a comfrey root (Symphyti offic. radix) extract ointment in the treatment of patients with painful osteoarthritis of the knee: results of a double-blind, randomised, bicenter, placebo-controlled trial

This randomised, double-blind, bicenter, placebo-controlled clinical trial investigated the effect of a daily application of 6g Kytta-Salbe f (3 x 2 g) over a 3 week period with patients suffering from painful osteoarthritis of the knee. The two hundred and twenty patients examined consisted of 153 women and 67 men of an average age of 57.9 years. On average, the complaints relating to osteoarthritis of the knee had persisted for 6.5 years. Two hundred and twenty patients were included in the Full Analysis Set (FAS) and safety collective, 186 (84.5%) in the Valid Case Analysis Set (VCAS) collective. In the course of the trial, the visual analog scale (VAS) total score (primary target value) in the verum group dropped by 51.6 mm (54.7%) and in the placebo group by 10.1 mm (10.7%). The average difference between the groups of 41.5 mm (95% confidence interval=34.8 to 48.2 mm) or 44.0% is significant (p<0.001). The significance is confirmed through the evaluation of the diary, the VCAS evaluation and the separate assessment of the two centres. This also applies to the separate assessment of the VAS total score following pain at rest and on movement. The WOMAC (Western Ontario and McMaster Universities) total score (secondary target value) also improved similar to the VAS total score. At the end of the trial, a reduction by 60.4 mm (58.0%) was recorded for the verum group and a reduction of 14.7 mm (14.1%) for the placebo group. The average group difference of 45.7 mm (95% confidence interval=37.1 to 54.3 mm) or 43.9% is significant (p<0.001). The difference between the treatment groups increased systematically and significantly, in parallel with the duration of the treatment. Thus, the superiority of the treatment with Kytta-Salbe f over that with the placebo is proven, even by means of the multi-factorial multivariate analysis for repetitive measurements. In respect of the explorative secondary target values SF-36 (quality of life), angle measurement (mobility of the knee), CGI (clinical global impression) and global assessment of efficacy by the physician and the patient, a significant superiority (p<0.001 each) of the verum group over the placebo group was also proven. The results suggest that the comfrey root extract ointment is well suited for the treatment of osteoarthritis of the knee. Pain is reduced, mobility of the knee improved and quality of life increased.

Global Gene Expression Profiling of Pleural Mesotheliomas: Overexpression of Aurora Kinases and P16/CDKN2A Deletion as Prognostic Factors and Critical Evaluation of Microarray-Based Prognostic Prediction

Most gene expression profiling studies of mesothelioma have been based on relatively small sample numbers, limiting their statistical power. We did Affymetrix U133A microarray analysis on 99 pleural mesotheliomas, in which multivariate analysis showed advanced-stage, sarcomatous histology and P16/CDKN2A homozygous deletion to be significant independent adverse prognostic factors. Comparison of the expression profiles of epithelioid versus sarcomatous mesotheliomas identified many genes significantly overexpressed among the former, including previously unrecognized ones, such as uroplakins and kallikrein 11, both confirmed by immunohistochemistry. Examination of the gene expression correlates of survival showed that more aggressive mesotheliomas expressed higher levels of Aurora kinases A and B and functionally related genes involved in mitosis and cell cycle control. Independent confirmation of the negative effect of Aurora kinase B was obtained by immunohistochemistry in a separate patient cohort. A role for Aurora kinases in the aggressive behavior of mesotheliomas is of potential clinical interest because of the recent development of small-molecule inhibitors. We then used our data to develop microarray-based predictors of 1 year survival; these achieved a maximal accuracy of 68% in cross-validation. However, this was inferior to prognostic prediction based on standard clinicopathologic variables and P16/CDNK2A status (accuracy, 73%), and adding the microarray model to the latter did not improve overall accuracy. Finally, we evaluated three recently published microarray-based outcome prediction models, but their accuracies ranged from 63% to 67%, consistently lower than reported. Gene expression profiling of mesotheliomas is an important discovery tool, but its power in clinical prognostication has been overestimated.

Hemithoracic radiation therapy after pleurectomy/decortication for malignant pleural mesothelioma

PURPOSE

To evaluate pleurectomy/decortication (P/D) and adjuvant radiotherapy (RT) in the treatment of malignant pleural mesothelioma (MPM).

METHODS AND MATERIALS

In a retrospective review, we included MPM patients treated with P/D and adjuvant RT at Memorial Sloan-Kettering Cancer Center from 1974 to 2003. When indicated, patients received intraoperative brachytherapy to residual tumor.

RESULTS

All 123 patients received external beam RT (median dose, 42.5 Gy; range, 7.2-67.8 Gy) to the ipsilateral hemithorax postoperatively. Fifty-four patients underwent brachytherapy (matched peripheral dose, 160 Gy). The median and 2-year overall survival for all patients was 13.5 months (range, 1-199 months) and 23%, respectively. One-year actuarial local control for all patients was 42%. Multivariate analysis for overall survival revealed radiation dose <40 Gy (p = 0.001), nonepithelioid histology (p = 0.002), left-sided disease (p = 0.01), and the use of an implant (p = 0.02) to be unfavorable. Two patients (1.6%) died from Grade 5 toxicity within 1 month of treatment.

CONCLUSIONS

Pleurectomy/decortication with adjuvant radiotherapy is not an effective treatment option for patients with MPM. Our results imply that residual disease cannot be eradicated with external RT with or without brachytherapy and that a more extensive surgery followed by external RT might be required to improve local control and overall survival.