Peter J. O'Dwyer

Inhibition of Mutated, Activated BRAF in Metastatic Melanoma

BACKGROUND The identification of somatic mutations in the gene encoding the serine-threonine protein kinase B-RAF (BRAF) in the majority of melanomas offers an opportunity to test oncogene-targeted therapy for this disease. METHODS We conducted a multicenter, phase 1, dose-escalation trial of PLX4032 (also known as RG7204), an orally available inhibitor of mutated BRAF, followed by an extension phase involving the maximum dose that could be administered without adverse effects (the recommended phase 2 dose). Patients received PLX4032 twice daily until they had disease progression. Pharmacokinetic analysis and tumor-response assessments were conducted in all patients. In selected patients, tumor biopsy was performed before and during treatment to validate BRAF inhibition. RESULTS A total of 55 patients (49 of whom had melanoma) were enrolled in the dose-escalation phase, and 32 additional patients with metastatic melanoma who had BRAF with the V600E mutation were enrolled in the extension phase. The recommended phase 2 dose was 960 mg twice daily, with increases in the dose limited by grade 2 or 3 rash, fatigue, and arthralgia. In the dose-escalation cohort, among the 16 patients with melanoma whose tumors carried the V600E BRAF mutation and who were receiving 240 mg or more of PLX4032 twice daily, 10 had a partial response and 1 had a complete response. Among the 32 patients in the extension cohort, 24 had a partial response and 2 had a complete response. The estimated median progression-free survival among all patients was more than 7 months. CONCLUSIONS Treatment of metastatic melanoma with PLX4032 in patients with tumors that carry the V600E BRAF mutation resulted in complete or partial tumor regression in the majority of patients. (Funded by Plexxikon and Roche Pharmaceuticals.)

Bevacizumab in Combination With Oxaliplatin, Fluorouracil, and Leucovorin (FOLFOX4) for Previously Treated Metastatic Colorectal Cancer: Results From the Eastern Cooperative Oncology Group Study E3200

PURPOSE Colorectal cancer is the second leading cause of cancer mortality in the United States. Antiangiogenic therapy with bevacizumab combined with chemotherapy improves survival in previously untreated metastatic colorectal cancer. This study was conducted to determine the effect of bevacizumab (at 10 mg/kg) on survival duration for oxaliplatin-based chemotherapy in patients with previously treated metastatic colorectal cancer. PATIENTS AND METHODS Eight hundred twenty-nine metastatic colorectal cancer patients previously treated with a fluoropyrimidine and irinotecan were randomly assigned to one of three treatment groups: oxaliplatin, fluorouracil, and leucovorin (FOLFOX4) with bevacizumab; FOLFOX4 without bevacizumab; or bevacizumab alone. The primary end point was overall survival, with additional determinations of progression-free survival, response, and toxicity. RESULTS The median duration of survival for the group treated with FOLFOX4 and bevacizumab was 12.9 months compared with 10.8 months for the group treated with FOLFOX4 alone (corresponding hazard ratio for death = 0.75; P = .0011), and 10.2 months for those treated with bevacizumab alone. The median progression-free survival for the group treated with FOLFOX4 in combination with bevacizumab was 7.3 months, compared with 4.7 months for the group treated with FOLFOX4 alone (corresponding hazard ratio for progression = 0.61; P < .0001), and 2.7 months for those treated with bevacizumab alone. The corresponding overall response rates were 22.7%, 8.6%, and 3.3%, respectively (P < .0001 for FOLFOX4 with bevacizumab v FOLFOX4 comparison). Bevacizumab was associated with hypertension, bleeding, and vomiting. CONCLUSION The addition of bevacizumab to oxaliplatin, fluorouracil, and leucovorin improves survival duration for patients with previously treated metastatic colorectal.

CD40 Agonists Alter Tumor Stroma and Show Efficacy Against Pancreatic Carcinoma in Mice and Humans

CD40 immunotherapy shows efficacy in treating pancreatic cancer in mice and humans by eliciting antitumor immunity. Immunosuppressive tumor microenvironments can restrain antitumor immunity, particularly in pancreatic ductal adenocarcinoma (PDA). Because CD40 activation can reverse immune suppression and drive antitumor T cell responses, we tested the combination of an agonist CD40 antibody with gemcitabine chemotherapy in a small cohort of patients with surgically incurable PDA and observed tumor regressions in some patients. We reproduced this treatment effect in a genetically engineered mouse model of PDA and found unexpectedly that tumor regression required macrophages but not T cells or gemcitabine. CD40-activated macrophages rapidly infiltrated tumors, became tumoricidal, and facilitated the depletion of tumor stroma. Thus, cancer immune surveillance does not necessarily depend on therapy-induced T cells; rather, our findings demonstrate a CD40-dependent mechanism for targeting tumor stroma in the treatment of cancer.

Phase II Trial of Sorafenib in Advanced Thyroid Cancer

PURPOSE Given the molecular pathophysiology of thyroid cancer and the spectrum of kinases inhibited by sorafenib, including Raf kinase, vascular endothelial growth factor receptors, platelet-derived growth factor receptor, and RET tyrosine kinases, we conducted an open-label phase II trial to determine the efficacy of sorafenib in patients with advanced thyroid carcinoma. PATIENTS AND METHODS Eligible patients with metastatic, iodine-refractory thyroid carcinoma received sorafenib 400 mg orally twice daily. Responses were measured radiographically every 2 to 3 months. The study end points included response rate, progression-free survival (PFS), and best response by Response Evaluation Criteria in Solid Tumors. RESULTS Thirty patients were entered onto the study and treated for a minimum of 16 weeks. Seven patients (23%; 95% CI, 0.10 to 0.42) had a partial response lasting 18+ to 84 weeks. Sixteen patients (53%; 95% CI, 0.34 to 0.72) had stable disease lasting 14 to 89+ weeks. Seventeen (95%) of 19 patients for whom serial thyroglobulin levels were available showed a marked and rapid response in thyroglobulin levels with a mean decrease of 70%. The median PFS was 79 weeks. Toxicity was consistent with other sorafenib trials, although a single patient died of liver failure that was likely treatment related. CONCLUSION Sorafenib has clinically relevant antitumor activity in patients with metastatic, iodine-refractory thyroid carcinoma, with an overall clinical benefit rate (partial response + stable disease) of 77%, median PFS of 79 weeks, and an overall acceptable safety profile. These results represent a significant advance over chemotherapy in both response rate and PFS and support further investigation of this agent in these patients.

Combined-Modality Treatment for Resectable Metastatic Colorectal Carcinoma to the Liver: Surgical Resection of Hepatic Metastases in Combination With Continuous Infusion of Chemotherapy—An Intergroup Study

PURPOSE Despite technical improvements that have minimized the morbidity and mortality of hepatic surgery, the long-term outcome of resection of hepatic metastases of colorectal cancer remains poor, with the majority of patients experiencing treatment failure in the liver. Because arterial chemotherapy regimens targeted to the liver have demonstrated high response rates, an intergroup trial of adjuvant therapy for patients undergoing hepatic resection of liver metastases from colorectal cancer was initiated. PATIENTS AND METHODS Patients with one to three potentially resectable metastases were randomized preoperatively to receive no further therapy (control arm, 56 patients) or postoperative hepatic arterial floxuridine combined with intravenous continuous-infusion fluorouracil (chemotherapy arm, 53 patients). After exclusion of patients identified as ineligible for the planned treatment at the time of surgery, there were 45 control patients and 30 on the chemotherapy arm. The study was powered to evaluate improvement in time to recurrence and hepatic disease-free survival, not overall survival. RESULTS The 4-year recurrence-free rate was 25% for the control arm and 46% for the chemotherapy group (P =.04). The 4-year liver recurrence-free rate was 43% in the control group and 67% in the chemotherapy group (P =.03). The median survival of the 75 assessable patients was 49 months for the control arm and 63.7 months for the chemotherapy arm (P =.60). The median survival of all 109 patients was 47 months for the control arm compared with 34 months for the chemotherapy arm (P =.19) CONCLUSION These data demonstrate that adjuvant intra-arterial and intravenous chemotherapy was beneficial in prolonging time to recurrence and pre-venting hepatic recurrence after hepatic resection of colorectal cancer.

Activity of the oral MEK inhibitor trametinib in patients with advanced melanoma: a phase 1 dose-escalation trial

BACKGROUND MEK is a member of the MAPK signalling cascade that is commonly activated in melanoma. Direct inhibition of MEK blocks cell proliferation and induces apoptosis. We aimed to analyse safety, efficacy, and genotyping data for the oral, small-molecule MEK inhibitor trametinib in patients with melanoma. METHODS We undertook a multicentre, phase 1 three-part study (dose escalation, cohort expansion, and pharmacodynamic assessment). The main results of this study are reported elsewhere; here we present data relating to patients with melanoma. We obtained tumour samples to assess BRAF mutational status, and available tissues underwent exploratory genotyping analysis. Disease response was measured by Response Evaluation Criteria in Solid Tumors, and adverse events were defined by common toxicity criteria. This study is registered with ClinicalTrials.gov, number NCT00687622. FINDINGS 97 patients with melanoma were enrolled, including 81 with cutaneous or unknown primary melanoma (36 BRAF mutant, 39 BRAF wild-type, six BRAF status unknown), and 16 with uveal melanoma. The most common treatment-related adverse events were rash or dermatitis acneiform (n=80; 82%) and diarrhoea (44; 45%), most of which were grade 2 or lower. No cutaneous squamous-cell carcinomas were recorded. Of 36 patients with BRAF mutations, 30 had not received a BRAF inhibitor before; two complete responses (both confirmed) and ten partial responses (eight confirmed) were noted in this subgroup (confirmed response rate, 33%). Median progression-free survival of this subgroup was 5·7 months (95% CI 4·0-7·4). Of the six patients who had received previous BRAF inhibition, one unconfirmed partial response was recorded. Of 39 patients with BRAF wild-type melanoma, four partial responses were confirmed (confirmed response rate, 10%). INTERPRETATION Our data show substantial clinical activity of trametinib in melanoma and suggest that MEK is a valid therapeutic target. Differences in response rates according to mutations indicate the importance of mutational analyses in the future. FUNDING GlaxoSmithKline.

Clinical Activity and Immune Modulation in Cancer Patients Treated With CP-870,893, a Novel CD40 Agonist Monoclonal Antibody

PURPOSE The cell-surface molecule CD40 activates antigen-presenting cells and enhances immune responses. CD40 is also expressed by solid tumors, but its engagement results in apoptosis. CP-870,893, a fully human and selective CD40 agonist monoclonal antibody (mAb), was tested for safety in a phase I dose-escalation study. PATIENTS AND METHODS Patients with advanced solid tumors received single doses of CP-870,893 intravenously. The primary objective was to determine safety and the maximum-tolerated dose (MTD). Secondary objectives included assessment of immune modulation and tumor response. RESULTS Twenty-nine patients received CP-870,893 in doses from 0.01 to 0.3 mg/kg. Dose-limiting toxicity was observed in two of seven patients at the 0.3 mg/kg dose level (venous thromboembolism and grade 3 headache). MTD was estimated as 0.2 mg/kg. The most common adverse event was cytokine release syndrome (grade 1 to 2) which included chills, rigors, and fever. Transient laboratory abnormalities affecting lymphocytes, monocytes, platelets, D-dimer and liver function tests were observed 24 to 48 hours after infusion. Four patients with melanoma (14% of all patients and 27% of melanoma patients) had objective partial responses at restaging (day 43). CP-870,893 infusion resulted in transient depletion of CD19+ B cells in blood (93% depletion at the MTD for < 1 week). Among B cells remaining in blood, we found a dose-related upregulation of costimulatory molecules after treatment. CONCLUSION The CD40 agonist mAb CP-870,893 was well tolerated and biologically active, and was associated with antitumor activity. Further studies of repeated doses of CP-870,893 alone and in combination with other antineoplastic agents are warranted.

Mechanisms of Hypertension Associated With BAY 43-9006

PURPOSE BAY 43-9006 (sorafenib) is an inhibitor of Raf kinase, the vascular endothelial growth factor (VEGF) receptor-2, and angiogenesis in tumor xenografts. The current study investigated the incidence, severity, and mechanism of blood pressure (BP) elevation in patients treated with BAY 43-9006. PATIENTS AND METHODS Twenty patients received BAY 43-9006 400 mg orally twice daily. BP and heart rate were measured at baseline and then every 3 weeks for 18 weeks. VEGF, catecholamines, endothelin I, urotensin II, renin, and aldosterone were measured at baseline and after 3 weeks of therapy. We assessed vascular stiffness at baseline, after 3 to 6 weeks of therapy, and again after 9 to 10 months of therapy. RESULTS Fifteen (75%) of 20 patients experienced an increase of > or = 10 mmHg in systolic BP (SBP), and 12 (60%) of 20 patients experienced an increase of > or = 20 mmHg in SBP compared with their baseline value, with a mean change of 20.6 mmHg (P < .0001) after 3 weeks of therapy. There were no statistically significant changes in humoral factors, although there was a statistically significant inverse relationship between decreases in catecholamines and increases in SBP, suggesting a secondary response to BP elevation. Measures of vascular stiffness increased significantly during the period of observation. CONCLUSION Treatment with BAY 43-9006 is associated with a significant and sustained increase in BP. The lack of significant change in circulating factors suggests that these humoral factors had little role in the increase in BP.

Phase I Dose-Escalation Study of Recombinant Human Apo2L/TRAIL, a Dual Proapoptotic Receptor Agonist, in Patients With Advanced Cancer

PURPOSE Apoptosis ligand 2/tumor necrosis factor-related apoptosis-inducing ligand (Apo2L/TRAIL)-a member of the tumor necrosis factor cytokine family-induces apoptosis by activating the extrinsic pathway through the proapoptotic death receptors DR4 and DR5. Recombinant human Apo2L/TRAIL (rhApo2L/TRAIL) has broad potential as a cancer therapy. To the best of our knowledge, this is the first in-human clinical trial to assess the safety, tolerability, pharmacokinetics, and antitumor activity of multiple intravenous doses of rhApo2L/TRAIL in patients with advanced cancer. PATIENTS AND METHODS This phase I, open-label, dose-escalation study treated patients with advanced cancer with rhApo2L/TRAIL doses ranging from 0.5 to 30 mg/kg/d, with parallel dose escalation for patients without liver metastases and with normal liver function (cohort 1) and for patients with liver metastases and normal or mildly abnormal liver function (cohort 2). Doses were given daily for 5 days, with cycles repeating every 3 weeks. Assessments included adverse events (AEs), laboratory tests, pharmacokinetics, and imaging to evaluate antitumor activity. RESULTS Seventy-one patients received a mean of 18.3 doses; seven patients completed all eight treatment cycles. The AE profile of rhApo2L/TRAIL was similar in cohorts 1 and 2. The most common AEs were fatigue (38%), nausea (28%), vomiting (23%), fever (23%), anemia (18%), and constipation (18%). Liver enzyme elevations were concurrent with progressive metastatic liver disease. Two patients with sarcoma (synovial and undifferentiated) experienced serious AEs associated with rapid tumor necrosis. Two patients with chondrosarcoma experienced durable partial responses to rhApo2L/TRAIL. CONCLUSION At the tested schedule and dose range, rhApo2L/TRAIL was safe and well tolerated. Dose escalation achieved peak rhApo2L/TRAIL serum concentrations equivalent to those associated with preclinical antitumor efficacy.

Paclitaxel and carboplatin in combination in the treatment of advanced non-small-cell lung cancer: a phase II toxicity, response, and survival analysis.

PURPOSE To determine the activity and toxicity of combination paclitaxel (24 hours) and carboplatin in advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS Eligibility required measurable disease (stage IV or stage IIIB with malignant pleural effusion), Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1, absolute neutrophil count > or = 2,000/microL, platelet count > or = 100,000/microL serum creatinine concentration < or = 1.5 mg/dL, and bilirubin level < or = 2 mg/dL. Paclitaxel was initially administered at a dose of 135 mg/m2/d, followed by carboplatin on day 2 at a targeted area under the concentration-time curve (AUC) of 7.5 using the Calvert formula. Granulocyte colony-stimulating factor (G-CSF) 5 micrograms/kg subcutaneously (SC) on days 3 to 17 was introduced during the second and subsequent cycles. In patients who sustained less than grade 4 myelosuppression, the paclitaxel dose was sequentially escalated 40 mg/m2 per cycle to a maximum of 215 mg/m2. Treatment was repeated at 3-week intervals for six cycles. RESULTS From June 1993 through February 1994, 54 patients were enrolled; 53 are assessable for toxicity and response. The median age was 62 years (range, 34 to 84). Sixty-nine percent were male, 65% had adenocarcinoma, and 93% had stage IV disease. Two hundred sixty-eight cycles were administered; 32 patients (59%) completed all six cycles. Twenty-five unanticipated hospitalizations occurred during treatment (9.3% of cycles) in 20 patients (37%). Myelosuppression was the principal toxicity; grade 3 or 4 granulocytopenia occurred in 57% of patients after the first cycle, but decreased to 35% during the second cycle after introduction of G-CSF and consistently remained < or = 22% during subsequent cycles. Seven episodes of neutropenic fever occurred, all during the first cycle. Grade 3 or 4 thrombocytopenia and anemia occurred in 47% and 33% of patients, respectively. Eight patients (15%) required platelet transfusions and 16 (30%) required packed RBC support. Neuropathy, myalgias/arthralgias, and thrombocytopenia, although generally mild, were cumulative. The paclitaxel dose was boosted to 215 mg/m2 in > or = 70% of patients who received three or more cycles. At an AUC of 7.5, the median first-cycle carboplatin dose was 424 mg/m2 (range, 273 to 709 mg/m2). The objective response rate was 62%, with five (9%) complete responses and 28 (53%) partial responses. The median progression-free survival time was 28 weeks and the median survival time 53 weeks. The 1-year survival rate is 54%. CONCLUSION The paclitaxel-carboplatin combination is active in advanced NSCLC and may enhance survival; it merits further investigation in phase III trials.