Alejandro D. Ricart

Phase I Trial of the Novel Mammalian Target of Rapamycin Inhibitor Deforolimus (AP23573; MK-8669) Administered Intravenously Daily for 5 Days Every 2 Weeks to Patients With Advanced Malignancies

PURPOSE This phase I trial was conducted to determine the safety, tolerability, pharmacokinetics, and pharmacodynamics of deforolimus (previously known as AP23573; MK-8669), a nonprodrug rapamycin analog, in patients with advanced solid malignancies. PATIENTS AND METHODS Patients were treated using an accelerated titration design with sequential escalating flat doses of deforolimus administered as a 30-minute intravenous infusion once daily for 5 consecutive days every 2 weeks (QDx5) in a 28-day cycle. Safety, pharmacokinetic, pharmacodynamic, and tumor response assessments were performed. RESULTS Thirty-two patients received at least one dose of deforolimus (3 to 28 mg/d). Three dose-limiting toxicity events of grade 3 mouth sores were reported. The maximum-tolerated dose (MTD) was 18.75 mg/d. Common treatment-related adverse events included reversible mouth sores and rash. Whole-blood clearance increased with dose. Pharmacodynamic analyses demonstrated mammalian target of rapamycin inhibition at all dose levels. Four patients (one each with non-small-cell lung cancer, mixed müllerian tumor [carcinosarcoma], renal cell carcinoma, and Ewing sarcoma) experienced confirmed partial responses, and three additional patients had minor tumor regressions. CONCLUSION The MTD of this phase I trial using an accelerated titration design was determined to be 18.75 mg/d. Deforolimus was well tolerated and showed encouraging antitumor activity across a broad range of malignancies when administered intravenously on the QDx5 schedule. On the basis of these overall results, a dose of 12.5 mg/d is being evaluated in phase II trials.

Axitinib plus gemcitabine versus placebo plus gemcitabine in patients with advanced pancreatic adenocarcinoma: a double-blind randomised phase 3 study

BACKGROUND Axitinib is a potent, selective inhibitor of vascular endothelial growth factor (VEGF) receptors 1, 2, and 3. A randomised phase 2 trial of gemcitabine with or without axitinib in advanced pancreatic cancer suggested increased overall survival in axitinib-treated patients. On the basis of these results, we aimed to assess the effect of treatment with gemcitabine plus axitinib on overall survival in a phase 3 trial. METHODS In this double-blind, placebo-controlled, phase 3 study, eligible patients had metastatic or locally advanced pancreatic adenocarcinoma, no uncontrolled hypertension or venous thrombosis, and Eastern Cooperative Oncology Group performance status 0 or 1. Patients, stratified by disease extent (metastatic vs locally advanced), were randomly assigned (1:1) to receive gemcitabine 1000 mg/m(2) intravenously on days 1, 8, and 15 every 28 days plus either axitinib or placebo. Axitinib or placebo were administered orally with food at a starting dose of 5 mg twice a day, which could be dose-titrated up to 10 mg twice daily if well tolerated. A centralised randomisation procedure was used to assign patients to each treatment group, with randomised permuted blocks within strata. Patients, investigators, and the trial sponsor were masked to treatment assignments. The primary endpoint was overall survival. All efficacy analyses were done in all patients assigned to treatment groups for whom data were available; safety and treatment administration and compliance assessments were based on treatment received. This study is registered at ClinicalTrials.gov, number NCT00471146. FINDINGS Between July 27, 2007, and Oct 31, 2008, 632 patients were enrolled and assigned to treatment groups (316 axitinib, 316 placebo). At an interim analysis in January, 2009, the independent data monitoring committee concluded that the futility boundary had been crossed. Median overall survival was 8·5 months (95% CI 6·9-9·5) for gemcitabine plus axitinib (n=314, data missing for two patients) and 8·3 months (6·9-10·3) for gemcitabine plus placebo (n=316; hazard ratio 1·014, 95% CI 0·786-1·309; one-sided p=0·5436). The most common grade 3 or higher adverse events for gemcitabine plus axitinib and gemcitabine plus placebo were hypertension (20 [7%] and 5 [2%] events, respectively), abdominal pain (20 [7%] and 17 [6%]), fatigue (27 [9%] and 21 [7%]), and anorexia (19 [6%] and 11 [4%]). INTERPRETATION The addition of axitinib to gemcitabine does not improve overall survival in advanced pancreatic cancer. These results add to increasing evidence that targeting of VEGF signalling is an ineffective strategy in this disease. FUNDING Pfizer.

Efficacy of gemcitabine plus axitinib compared with gemcitabine alone in patients with advanced pancreatic cancer: an open-label randomised phase II study

BACKGROUND Axitinib (AG-013736) is a potent and selective oral inhibitor of vascular endothelial growth factor receptors 1, 2, and 3, which have an important role in pancreatic cancer. The aim of this study was to assess the safety and efficacy of gemcitabine plus axitinib versus gemcitabine alone. METHODS Between January and August, 2006, 103 patients with unresectable, locally advanced, or metastatic pancreatic cancer were randomly assigned in a two to one ratio to receive gemcitabine (1000 mg/m(2)) plus axitinib 5 mg twice daily (n=69) or gemcitabine (1000 mg/m(2)) alone (n=34) by a centralised registration system. The primary endpoint was overall survival. Analyses were done by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00219557. FINDINGS All randomised patients were included in the efficacy analyses. Median overall survival was longer with gemcitabine plus axitinib than with gemcitabine alone (6.9 [95% CI 5.3-10.1] months vs 5.6 [3.9-8.8] months). The hazard ratio for survival with gemcitabine plus axitinib versus with gemcitabine alone, adjusted for stratification factors, was 0.71 (95% CI 0.44-1.13). The most common grade 3 or worse adverse events were fatigue (15 [22%] patients in the gemcitabine plus axitinib group vs one [3%] in the gemcitabine alone group), abdominal pain (eight [12%] vs five [16%]), and asthenia (eight [12%] vs one [3%]). INTERPRETATION Gemcitabine plus axitinib showed a similar safety profile to gemcitabine alone; the small, non-statistically significant gain in overall survival needs to be assessed in a randomised phase III trial.

A Phase II Study of PD-0325901, an Oral MEK Inhibitor, in Previously Treated Patients with Advanced Non–Small Cell Lung Cancer

Purpose: To evaluate the efficacy of mitogen-activated protein kinase/extracellular signal-related kinase kinase inhibitor PD-0325901 in advanced non–small cell lung cancer patients who had experienced treatment failure after, or were refractory to, standard systemic therapy. Experimental Design: This open-label, phase II study initially evaluated 15 mg PD-0325901 twice daily administered intermittently (3 weeks on/1 week off; schedule A). As this schedule was not well tolerated, a second schedule was introduced as follows: 5 days on/2 days off for 3 weeks, followed by 1 week off (schedule B). The primary end point was objective response. Results: All patients had received prior systemic therapy (median of two regimens, including epidermal growth factor receptor inhibitors in 26%). Of 13 patients treated on schedule A, three discontinued due to adverse events (blurred vision, fatigue, and hallucinations, respectively). Twenty-one patients received schedule B. Main toxicities included diarrhea, fatigue, rash, vomiting, nausea, and reversible visual disturbances. Hematologic toxicity consisted mainly of mild-to-moderate anemia, without neutropenia. Chemistry abnormalities were rare. Mean (coefficient of variation) PD-0325901 trough plasma concentrations were 100 ng/mL (52%) and 173 ng/mL (73%) for schedules A and B, respectively, above the minimum target concentration established in preclinical studies (16.5 ng/mL). There were no objective responses. Seven patients had stable disease. Median (95% confidence interval) progression-free survival was 1.8 months (1.5-1.9) and overall survival was 7.8 months (4.5-13.9). Conclusions: PD-0325901 did not meet its primary efficacy end point. Future studies should focus on PD-0325901 schedule, rational combination strategies, and enrichment of patient selection based on mode of action. Clin Cancer Res; 16(8); 2450–7. ©2010 AACR.

Phase I Pharmacokinetic and Pharmacodynamic Study of the Oral MAPK/ERK Kinase Inhibitor PD-0325901 in Patients with Advanced Cancers

Purpose: To determine tolerability, pharmacokinetics, and pharmacodynamics of PD-0325901, a highly potent, selective, oral mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK) kinase 1/2 inhibitor in advanced cancer patients. Experimental Design: Sixty-six patients received PD-0325901 at doses from 1 mg once daily to 30 mg twice daily (BID). Cycles were 28 days; three administration schedules were evaluated. Pharmacokinetic parameters were assessed and tumor biopsies were done to evaluate pharmacodynamics. Results: Common adverse events were rash, diarrhea, fatigue, nausea, and visual disturbances including retinal vein occlusion (RVO; n = 3). Neurotoxicity was frequent in patients receiving ≥15 mg BID. The maximum tolerated dose, 15 mg BID continuously, was associated with late-onset RVO outside the dose-limiting toxicity window. An alternative dose and schedule, 10 mg BID 5 days on/2 days off, was therefore expanded; one RVO event occurred. Three of 48 evaluable patients with melanoma achieved confirmed partial responses; 10 had stable disease ≥4 months. PD-0325901 exposure was generally dose proportional. Doses ≥2 mg BID consistently caused ≥60% suppression of phosphorylated ERK in melanoma. Fifteen patients showed significant decreases (≥50%) in Ki-67. Conclusions: PD-0325901 showed preliminary clinical activity. The maximum tolerated dose, based on first cycle dose-limiting toxicities, was 15 mg BID continuously. However, 10 and 15 mg BID continuous dosing and 10 mg BID 5 days on/2 days off schedules were associated with delayed development of RVO; thus, further enrollment to this trial was stopped. Intermittent dose scheduling between 2 and 10 mg BID should be explored to identify a recommended dose with long-term PD-0325901 use. Clin Cancer Res; 16(6); 1924–37

Antibody-Drug Conjugates of Calicheamicin Derivative: Gemtuzumab Ozogamicin and Inotuzumab Ozogamicin

Antibody-drug conjugates (ADC) are an attractive approach for the treatment of acute myeloid leukemia and non-Hodgkin lymphomas, which in most cases, are inherently sensitive to cytotoxic agents. CD33 and CD22 are specific markers of myeloid leukemias and B-cell malignancies, respectively. These endocytic receptors are ideal for an ADC strategy because they can effectively carry the cytotoxic payload into the cell. Gemtuzumab ozogamicin (GO, Mylotarg) and inotuzumab ozogamicin consist of a derivative of calicheamicin (a potent DNA-binding cytotoxic antibiotic) linked to a humanized monoclonal IgG4 antibody directed against CD33 or CD22, respectively. Both of these ADCs have a target-mediated pharmacokinetic disposition. GO was the first drug to prove the ADC concept in the clinic, specifically in phase II studies that included substantial proportions of older patients with relapsed acute myeloid leukemia. In contrast, in phase III studies, it has thus far failed to show clinical benefit in first-line treatment in combination with standard chemotherapy. Inotuzumab ozogamicin has shown remarkable clinical activity in relapsed/refractory B-cell non-Hodgkin lymphoma, and it has started phase III evaluation. The safety profile of these ADCs includes reversible myelosuppression (especially neutropenia and thrombocytopenia), elevated hepatic transaminases, and hyperbilirubinemia. There have been postmarketing reports of hepatotoxicity, especially veno-occlusive disease, associated with GO. The incidence is ∼2%, but patients who undergo hematopoietic stem cell transplantation have an increased risk. As we steadily move toward the goal of personalized medicine, these kinds of agents will provide a unique opportunity to treat selected patient subpopulations based on the expression of their specific tumor targets. Clin Cancer Res; 17(20); 6417–27. ©2011 AACR.

Diastolic Blood Pressure as a Biomarker of Axitinib Efficacy in Solid Tumors

Purpose: To evaluate if diastolic blood pressure (dBP) ≥90 mm Hg during axitinib treatment is a marker of efficacy. Experimental Design: The relationship between dBP ≥90 mm Hg and efficacy was retrospectively explored across 5 phase II studies of single-agent axitinib for the treatment of 4 different tumor types. All patients had baseline BP ≤140/90 mm Hg and were stratified into 2 groups based on in-clinic BP measurements after initiating therapy: those with dBP <90 mm Hg throughout therapy and those with at least 1 dBP ≥90 mm Hg. Median overall survival (mOS), median progression-free survival (mPFS), objective response rate (ORR), and adverse events were evaluated by dBP group in individual and pooled analyses. Results: Two-hundred thirty patients were evaluated. Patients with dBP ≥90 mm Hg had a significantly lower relative risk of death than those with dBP <90 mm Hg [adjusted HR (95% CI) = 0.55 (0.39, 0.77); P < 0.001]. The relative risk of progression was also lower in patients with dBP ≥90 mm Hg [HR (95% CI) = 0.76 (0.54, 1.06), P = 0.107], and ORR was significantly higher (43.9% vs. 12.0%; P < 0.001). In an 8-week landmark analysis, mOS (25.8 vs. 14.9 months) and mPFS (10.2 vs. 7.1 months) were greater for patients in the ≥90 mm Hg group. Adverse events were similar between groups. Conclusions: Axitinib efficacy correlated with dBP ≥90 mm Hg. Further investigation of dBP as a predictive biomarker of efficacy in patients receiving axitinib is warranted. Clin Cancer Res; 17(11); 3841–9. ©2011 AACR.

Technology Insight: cytotoxic drug immunoconjugates for cancer therapy

The successful introduction of genetically engineered human and chimeric immunoglobulin proteins has established monoclonal antibodies (mAbs) as a validated approach for treating malignancies. The unique properties of mAb therapies including their high affinity and specificity, and the differential expression of target antigen in tumor cells versus normal cells make them attractive agents for cancer immunotherapy. The field of immunoconjugate development attempts to combine the specificity of mAb therapies with cytotoxic and radionuclide molecules, thereby combining the best characteristics of these two different modalities. Two radiolabeled mAbs, 90Y-ibritumomab tiuxetan and 131I-tositumomab, and one drug conjugate, gemtuzumab ozogamicin have been approved for the treatment of malignancies. Other conjugates carrying toxic payloads of calicheamicin, geldanamycin, maytansinoids and taxoids as well as peptide exotoxins are undergoing preclinical and clinical development. Nevertheless, several obstacles have limited robust antitumor activity and broad application of imunoconjugates, including the optimization of three structural components of the immunoconjugate (i.e. mAb and target specificity, chemical linker design, and the cytotoxin), as well as issues common to mAb therapy such as heterogeneous antigen expression, which can limit uniform antibody delivery. This Review examines optimal design, the lessons learned from clinical immunoconjugate development, and the promising agents in early preclinical/clinical development for the treatment of cancer.

Axitinib or Bevacizumab Plus FOLFIRI or Modified FOLFOX-6 After Failure of First-Line Therapy for Metastatic Colorectal Cancer: A Randomized Phase II Study

OBJECTIVE Axitinib, a potent and selective second-generation inhibitor of vascular endothelial growth factor receptors 1, 2, and 3, shows activity in multiple tumor types, including those refractory to previous antiangiogenic therapy. This randomized, multicenter, parallel-group, open-label phase II trial compared axitinib with bevacizumab each in combination with 5-fluorouracil/leucovorin/oxaliplatin (FOLFOX) or 5-fluorouracil/leucovorin/irinotecan (FOLFIRI) for second-line treatment of metastatic colorectal cancer. METHODS Patients were randomized 1:1 to axitinib 5 mg twice daily or bevacizumab 5 mg/kg every 2 weeks plus modified FOLFOX-6 (if previously treated with irinotecan) or FOLFIRI (if previously treated with oxaliplatin) and were stratified by performance status and prior bevacizumab therapy. Primary endpoint was progression-free survival. RESULTS In 171 patients, progression-free survival was 7.6 months with axitinib/FOLFOX vs. 6.4 months with bevacizumab/FOLFOX (hazard ratio [HR], 1.04; 95% confidence interval [CI], 0.55-1.96; 1-sided P = .55) and 5.7 months with axitinib/FOLFIRI vs. 6.9 months with bevacizumab/FOLFIRI (HR, 1.27; 95% CI, 0.77-2.11; 1-sided P = .83). Overall survival was 17.1 vs. 14.1 months with axitinib/FOLFOX and bevacizumab/FOLFOX (HR, 0.69; 95% CI, 0.37-1.27; 1-sided P = .12) and 12.9 vs. 15.7 months with axitinib/FOLFIRI and bevacizumab/FOLFIRI (HR, 1.36; 95% CI, 0.82-2.24; 1-sided P = .88). More grade ≥ 3 adverse events (eg, diarrhea, fatigue, decreased appetite) and treatment discontinuations due to adverse events occurred with axitinib. CONCLUSIONS Compared with bevacizumab, axitinib did not improve outcomes when added to second-line chemotherapy for metastatic colorectal cancer. With current dosing regimens, axitinib plus FOLFOX or FOLFIRI seems to be less well tolerated than bevacizumab-based regimens.

Satraplatin, an oral platinum, administered on a five-day every-five-week schedule: a pharmacokinetic and food effect study.

Purpose: The study aimed to assess the pharmacokinetic behavior of satraplatin under fasted and fed conditions, and its safety and preliminary antitumor activity in adults with advanced solid tumors. Experimental Design: Satraplatin was administered orally at 80 mg/m2 once daily with prophylactic antiemetics for 5 consecutive days every 5 weeks. Patients were randomized to receive day 1 and day 5 doses of satraplatin in either the fed or fasted state, the order being reversed for cycle 2. Pharmacokinetic sampling was done during the first two cycles. For all subsequent cycles, patients received satraplatin in the fasted state. Results: Seventeen patients were treated with 60 total cycles of satraplatin. There was no dose-limiting toxicity during cycle 1. Severe hematologic toxicity was rare and the hematologic nadir occurred during week 4. Nausea, vomiting, and diarrhea were grade 1/2. No significant cardiac, renal, hepatic, or neurologic toxicity was observed. The hypothesis that food decreased ultrafiltrate platinum bioavailability could not be rejected, as the lower limit of the 90% confidence intervals for peak plasma concentration and area under the concentration-time curve from time 0 to 24 hours were 56.14% and 73.53%, respectively, both below the 80% bioequivalence acceptance criterion. One partial response (hormone refractory prostate cancer) and four durable stable diseases (breast, ovarian, parotid, and hormone refractory prostate cancer) were confirmed. Conclusions: There is an effect of food on the pharmacokinetics of satraplatin, the clinical significance of which is unclear. It is recommended that satraplatin be administered in the fasting state. This 5-week interval schedule of satraplatin was well tolerated in heavily pretreated patients.