Tissue/Site-Agnostic Study of Ribociclib for Tumors With Cyclin D-CDK4/6 Pathway Genomic Alterations: A Phase II, Open-Label, Single-Arm Basket Study

PURPOSE

As part of the Novartis Signature Program, this study evaluated the efficacy of ribociclib (selective cyclin-dependent kinase 4/6 [CDK4/6] inhibitor) in patients with cyclin D-CDK4/6 pathway-aberrant tumors.

METHODS

This was a phase II, single-arm, signal-seeking study in patients with advanced malignancies that had progressed on or after standard treatment. Prior identification of tumor CDK4/6 mutation or amplification, CCND1/3 amplification, or CDKN2A mutation or loss was required. Clinical benefit (defined as the proportion of patients with response or stable disease at ≥ 16 weeks) was the primary end point.

RESULTS

From 61 centers in the United States, 106 patients (median age, 62.5 years) were enrolled across multiple malignancies. The patient population was heavily pretreated (median number of prior therapies, three; range, 0 to 19). Median progression-free survival was 1.8 months (95% CI, 1.8 to 1.9). In patients with solid tumors, the clinical benefit rate was 18.1% (n = 19 of 105) and the overall response rate was 2.9% (n = 3 of 105); three partial responses occurred in patients with adenocarcinoma (unknown primary), soft tissue sarcoma, and urothelial carcinoma. No tumor cohort met the prespecified criteria for success. The most common adverse events suspected to be related to treatment were neutropenia (30.2%; decreased neutrophils, 15.1%), fatigue (31.1%), and nausea (29.2%). Fatigue and nausea were typically mild. Only one incident of febrile neutropenia was experienced (grade 3).

CONCLUSION

No new or unexpected safety signals were observed in this heavily pretreated patient population. Although responses were seen in tumors with CCND1-CDK4/6 amplifications, the primary end point was not met, suggesting additional evaluation of ribociclib, possibly as combination therapy, is needed.

Treatment patterns, health care resource utilization, and costs in patients with relapsed/refractory Hodgkin lymphoma treated with brentuximab vedotin

Data are limited on the real-world utilization and costs of brentuximab vedotin (BV) among patients with relapsed/refractory Hodgkin lymphoma (rrHL) in the United States. A total of 219 BV patients identified from the Truven MarketScan^® databases were followed up for a median of 2.9 years before and 1.0 year after initiation of BV. Of these patients, 109 (50.6%) received systemic therapy after BV (post-BV ST). Median duration of treatment was short for BV (2.1 months) and post-BV ST treatment (1.3 months); time to next treatment was 6.2 and 9.1 months, respectively. Average total US dollar 2014 costs/person for BV and post-BV ST line of therapy were $167,152 and $132,115, respectively; mean per-patient-per-month costs for BV and post-BV ST were $30,434 and $29,138, respectively. Findings underscore the unmet medical need and substantial economic burden in BV-treated patients with rrHL.

Phase II Study of the Efficacy and Safety of Pembrolizumab for Relapsed/Refractory Classic Hodgkin Lymphoma

Purpose Hodgkin Reed-Sternberg cells harbor alterations in chromosome 9p24.1, leading to overexpression of programmed death-ligand 1 (PD-L1) and PD-L2. Pembrolizumab, a programmed death 1-blocking antibody, demonstrated a high overall response rate (ORR) in patients with relapsed or refractory classic Hodgkin lymphoma (rrHL) in phase I testing. Methods KEYNOTE-087 ( ClinicalTrials.gov identifier, NCT02453594) was a single-arm phase II study of pembrolizumab in three cohorts of patients with rrHL, defined on the basis of lymphoma progression after (1) autologous stem cell transplantation (ASCT) and subsequent brentuximab vedotin (BV); (2) salvage chemotherapy and BV, and thus, ineligible for ASCT because of chemoresistant disease; and (3) ASCT, but without BV after transplantation. Patients received pembrolizumab 200 mg once every 3 weeks. Response was assessed every 12 weeks. The primary end points were ORR by central review and safety. Results A total of 210 patients were enrolled and treated (69 in cohort 1, 81 in cohort 2, and 60 in cohort 3). At the time of analysis, patients received a median of 13 treatment cycles. Per central review, the ORR was 69.0% (95% CI, 62.3% to 75.2%), and the complete response rate was 22.4% (95% CI, 16.9% to 28.6%). By cohort, ORRs were 73.9% for cohort 1, 64.2% for cohort 2, and 70.0% for cohort 3. Thirty-one patients had a response ≥ 6 months. The safety profile was largely consistent with previous pembrolizumab studies. Conclusion Pembrolizumab was associated with high response rates and an acceptable safety profile in patients with rrHL, offering a new treatment paradigm for this disease.

Programmed Death-1 Blockade With Pembrolizumab in Patients With Classical Hodgkin Lymphoma After Brentuximab Vedotin Failure

Purpose Classical Hodgkin lymphoma (HL) frequently exhibits genetic alterations leading to overexpression of the programmed death-1 (PD-1) ligands, suggesting a possible vulnerability to PD-1 blockade. The phase Ib study KEYNOTE-013 (NCT01953692) tested the safety and efficacy of the anti-PD-1 antibody pembrolizumab in patients with hematologic malignancies. Based on its genetics, HL was included as an independent cohort. Methods We enrolled patients with relapsed or refractory HL whose disease progressed on or after treatment with brentuximab vedotin. Patients received pembrolizumab, 10 mg/kg every 2 weeks, until disease progression occurred. Response to treatment was assessed at week 12 and every 8 weeks thereafter. Principal end points were safety and complete remission (CR) rate. Results Thirty-one patients were enrolled; 55% had more than four lines of prior therapy, and 71% had relapsed after autologous stem cell transplantation. Five patients (16%) experienced grade 3 drug-related adverse events (AEs); there were no grade 4 AEs or deaths related to treatment. The CR rate was 16% (90% CI, 7% to 31%). In addition, 48% of patients achieved a partial remission, for an overall response rate of 65% (90% CI, 48% to 79%). Most of the responses (70%) lasted longer than 24 weeks (range, 0.14+ to 74+ weeks), with a median follow-up of 17 months. The progression-free survival rate was 69% at 24 weeks and 46% at 52 weeks. Biomarker analyses demonstrated a high prevalence of PD-L1 and PD-L2 expression, treatment-induced expansion of T cells and natural killer cells, and activation of interferon-γ, T-cell receptor, and expanded immune-related signaling pathways. Conclusions Pembrolizumab was associated with a favorable safety profile. Pembrolizumab treatment induced favorable responses in a heavily pretreated patient cohort, justifying further studies.

A pharmacodynamically guided dose selection of PF-00337210 in a phase I study in patients with advanced solid tumors

PURPOSE

PF-00337210 is an oral, highly selective vascular endothelial growth factor receptor (VEGFR) inhibitor. We evaluated a composite of biomarkers in real time to identify the recommended phase 2 dose (RP2D) and preliminary anticancer activity of PF-00337210.

PATIENTS AND METHODS

Patients (Pts) with advanced cancers were treated once (QD) or twice daily (BID) with escalating doses. Acute effects on tumor perfusion and vascularity were assessed using DCE-MRI, weekly BP readings, soluble VEGFR-2, and hemoglobin levels.

RESULTS

Forty-six pts were treated with 0.67-9 mg QD and 4-6 mg BID of PF-00337210. Nineteen pts (41%) previously received VEGF/VEGFR inhibitors. Two pts had dose-limiting toxicity (DLT) at 9 mg QD (troponin I increase and hypertension). The MTD at QD dose was 8 mg. Common drug-related adverse events were hypertension, fatigue, proteinuria, and nausea. Hypertension incidence and intensity corresponded with dose, but was well controlled with medication. Two confirmed partial responses and minor regressions (>10 to <30% reduction in target lesions) were noted. Complete DCE-MRI was acquired in 21 pts (20 evaluable for vascular response). Ten pts were vascular responders, including 5/6 pts at BID doses. Greatest modulation of soluble VEGFR-2 was at 6 mg BID. The maximum change from baseline in diastolic BP was higher at BID doses. There were no significant differences for systolic BP and hemoglobin levels.

CONCLUSIONS

PF-00337210 has profound VEGFR inhibition effects at well-tolerated doses. Antitumor activity and VEGF inhibition effects were observed across BID doses. The RP2D was 6 mg BID.

A randomized phase 1 pharmacokinetic trial comparing the potential biosimilar PF-05280014 with trastuzumab in healthy volunteers (REFLECTIONS B327-01)

AIMS

The pharmacokinetic (PK) similarity between PF-05280014, a proposed trastuzumab biosimilar, trastuzumab sourced from European Union (trastuzumab-EU) or from United States (trastuzumab-US) was evaluated. Safety and immunogenicity were also assessed.

METHODS

In this phase 1, double-blind trial (NCT01603264), 105 healthy male volunteers were randomized 1:1:1 to receive a single 6 mg kg(-1) intravenous dose of PF-05280014, trastuzumab-EU, or trastuzumab-US, and evaluated for 70 days. Drug concentration-time data were analyzed by non-compartmental methods. PK similarity for the comparisons of PF-05280014 to each of trastuzumab-EU and trastuzumab-US, and trastuzumab-EU to trastuzumab-US were determined using the standard 80.00% to 125.00% bioequivalence criteria.

RESULTS

Baseline demographics for the 101 subjects evaluable for PK were similar across all arms. The three products exhibited similar PK profiles with target-mediated disposition. The 90% CIs for the ratios of Cmax , AUC (0 , t last) and AUC(0,∞) were within 80.00% to 125.00% for all three pairwise comparisons. Adverse events (AEs) were similar across all arms with treatment-related AEs reported by 71.4%, 68.6% and 65.7% subjects in the PF-05280014, trastuzumab-EU, and trastuzumab-US arms, respectively. The most common AEs were infusion-related reactions, headache, chills, pyrexia and nausea. The AE term 'pyrexia' was numerically greater in the PF-05280014 arm. All post-dose samples, except 1, tested negative for anti-drug antibodies (ADA).

CONCLUSIONS

This study demonstrates PK similarity among PF-05280014, trastuzumab-EU and trastuzumab-US. The safety and immunogenicity profiles observed for the three products in this study are consistent with previous reports for trastuzumab.

A phase I pharmacokinetics trial comparing PF-05280014 (a potential biosimilar) and trastuzumab in healthy volunteers (REFLECTIONS B327-01)

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Background: PF-05280014, a proposed biosimilar to trastuzumab, has an identical amino acid sequence and similar physicochemical and in vitro functional properties to trastuzumab. This study was designed to demonstrate PK similarity of PF-05280014 to trastuzumab from the US (trastuzumab-US) and EU (trastuzumab-EU), and between the licensed drugs. Safety and immunogenicity were also evaluated. Methods: In this double-blind trial (NCT01603264), 105 healthy male volunteers, 18-55 years old were randomized 1:1:1 to receive a single 6 mg/kg IV dose of PF-05280014, trastuzumab-US or trastuzumab-EU. All subjects provided informed consent. PK, safety and immunogenicity assessments were conducted for 70 days. PK similarity for a given test-to-reference comparison was considered to be demonstrated if the 90% CI of the test-to-reference ratio of the AUC from time 0 to the last time point (AUCT) and maximum concentration (Cmax) were within 80% – 125%. Results: The baseline demographics for the 101 subjects evaluable for PK were similar among 3 treatment arms. The 3 study drugs exhibited similar characteristics of target-mediated disposition and similar PK parameters (Table). The 90% CI for the ratios of Cmax, AUCT, and AUC0-∞were within 80% – 125% for the comparisons of PF-05280014 to trastuzumab-EU or trastuzumab-US, and trastuzumab-EU to trastuzumab-US. Adverse events (AE) were similar for the 3 arms with treatment-related AEs reported by 71.4%, 68.6%, and 65.7% subjects in the PF-05280014, trastuzumab-EU and trastuzumab-US, respectively. No serious AEs were reported. Only 4 subjects had treatment interruptions; 2 discontinued. Only 1 subject (trastuzumab-EU) developed anti-drug antibodies after dosing. Conclusions: This study demonstrates PK similarity of PF-05280014 to both trastuzumab-US and trastuzumab-EU and of trastuzumab-EU to trastuzumab-US. The 3 study drugs also showed similar safety profiles. Clinical trial information: NCT01603264. [Table: see text]

A phase I pharmacokinetics trial comparing PF-05280014 (a potential biosimilar) and trastuzumab in healthy volunteers (REFLECTIONS B327-01)

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Background: PF-05280014, a proposed biosimilar to trastuzumab, has an identical amino acid sequence and similar physicochemical and in vitro functional properties to trastuzumab. This study was designed to demonstrate PK similarity of PF-05280014 to trastuzumab from the US (trastuzumab-US) and EU (trastuzumab-EU), and between the licensed drugs. Safety and immunogenicity were also evaluated. Methods: In this double-blind trial (NCT01603264), 105 healthy male volunteers, 18-55 years old were randomized 1:1:1 to receive a single 6 mg/kg IV dose of PF-05280014, trastuzumab-US or trastuzumab-EU. All subjects provided informed consent. PK, safety, and immunogenicity assessments were conducted for 70 days. PK similarity for a given test-to-reference comparison was considered to be demonstrated if the 90% CI of the test-to-reference ratio of the AUC from time 0 to the last time point (AUCT) and maximum concentration (Cmax) were within 80% – 125%. Results: The baseline demographics for the 101 subjects evaluable for PK were similar among 3 treatment arms. The 3 study drugs exhibited similar characteristics of target-mediated disposition and similar PK parameters (Table). The 90% CI for the ratios of Cmax, AUCT, and AUC0-∞were within 80% – 125% for the comparisons of PF-05280014 to trastuzumab-EU or trastuzumab-US, and trastuzumab-EU to trastuzumab-US. Adverse events (AE) were similar for the 3 arms with treatment-related AEs reported by 71.4%, 68.6%, and 65.7% subjects in the PF-05280014, trastuzumab-EU and trastuzumab-US, respectively. No serious AEs were reported. Only 4 subjects had treatment interruptions; 2 discontinued. Only 1 subject (trastuzumab-EU) developed anti-drug antibodies after dosing. Conclusions: This study demonstrates PK similarity of PF-05280014 to both trastuzumab-US and trastuzumab-EU and of trastuzumab-EU to trastuzumab-US. The three study drugs also showed similar safety profiles. Clinical trial information: NCT01603264. [Table: see text]

Abstract OT1-1-05: A Phase I pharmacokinetics trial comparing PF-05280014 and trastuzumab in healthy volunteers (REFLECTIONS B327-01)

Background: Trastuzumab is a humanized recombinant monoclonal antibody that selectively binds the extracellular domain of human epidermal growth factor receptor 2 (HER2) and is approved for treatment of breast and gastric cancers. PF05280014 is being developed as a potential biosimilar to trastuzumab. In nonclinical evaluations, PF-05280014 has an identical amino acid sequence to trastuzumab and similar physicochemical and in vitro functional properties. The goal of this phase I trial is to demonstrate the pharmacokinetic similarity of PF-05280014 to trastuzumab sourced from both the United States (trastuzumab-US) and European Union (trastuzumab-EU).

Trial design: In this double-blind, parallel group, single dose trial, subjects will be randomized 1:1:1 into 3 arms: PF-05280014; trastuzumab-US, and trastuzumab-EU (NCT01603264).

Eligibility: Healthy male volunteers, 18–55 years of age with normal left ventricular ejection fraction are eligible. Multiple exclusion criteria common to Phase 1 trials are in effect. All subjects must provide informed consent.

Aims: The primary objectives are to demonstrate the pharmacokinetic similarity of PF-05280014 to trastuzumab-US and trastuzumab-EU. Secondary objectives include evaluating the safety, tolerability, and immunogenicity of PF-05280014 compared with US-licensed and EU-approved trastuzumab products.

Statistical methods: Pharmacokinetic similarity will be demonstrated if the 90% confidence interval of the ratio of the area under the concentration-versus-time curve from time 0 to the last time point with quantifiable concentration (AUCT) and maximum concentration (Cmax) of PF-05280014 to both trastuzumab-US and trastuzumab-EU are within 80%–125%. At least 93 subjects, 31/arm, will be needed to provide &gt;81% power to demonstrate pharmacokinetic similarity for all comparisons. The planned enrolment is 105 subjects to account for subjects who may not complete the full follow-up period. The intent-to-treat (ITT) population is defined as all subjects who are randomized to receive treatment. The modified ITT population is defined as all subjects who are randomized and receive at least one dose of treatment and will be used to assess safety, tolerability, and immunogenicity. The per-protocol population is defined as all subjects who are randomized to and receive treatment and do not have any major protocol violations and will be used for the primary evaluation of pharmacokinetic parameters.

Accrual: The target accrual is 105 subjects; present accrual is 17subjects.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr OT1-1-05.

A phase I dose-escalation trial of 2-deoxy-D-glucose alone or combined with docetaxel in patients with advanced solid tumors

PURPOSE

This phase I trial was initiated to evaluate the safety, pharmacokinetics (PK) and maximum tolerated dose (MTD) of the glycolytic inhibitor, 2-deoxy-D-glucose (2DG) in combination with docetaxel, in patients with advanced solid tumors.

METHODS

A modified accelerated titration design was used. 2DG was administered orally once daily for 7 days every other week starting at a dose of 2 mg/kg and docetaxel was administered intravenously at 30 mg/m(2) for 3 of every 4 weeks beginning on day 1 of week 2. Following the completion of dose escalation, cohorts of patients were then treated with 2DG for 21 days or every day of each 4-week cycle for up to 12 cycles.

RESULTS

Thirty-four patients were enrolled: 21 on every other week, 6 on a 21 of 28-day cycle and 7 on the continuous 2DG dosing schedule. There were no dose-limiting toxicities which met the MTD criteria. The most common adverse events were fatigue, sweating, dizziness and nausea mimicking the hypoglycemic symptoms expected from 2DG administration. Therefore, 63 mg/kg was selected as the clinically tolerable dose. The most significant adverse effects noted at 63-88 mg/kg doses were reversible hyperglycemia (100 %), gastrointestinal bleeding (6 %) and reversible grade 3 QTc prolongation (22 %). Eleven patients (32 %) had stable disease, 1 patient (3 %) partial response and 22 patients (66 %) progressive disease as their best response. There was no PK interaction between 2DG and docetaxel.

CONCLUSION

The recommended dose of 2DG in combination with weekly docetaxel is 63 mg/kg/day with tolerable adverse effects.

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.

Phase I study of E7820, an oral inhibitor of integrin alpha-2 expression with antiangiogenic properties, in patients with advanced malignancies

PURPOSE

This phase I study was conducted to characterize the safety profile, pharmacokinetics, pharmacodynamics, dose-limiting toxicity (DLT), and the maximum-tolerated dose of E7820, a novel oral sulfonamide derivative with antiangiogenic properties, when administered to patients with advanced solid malignancies.

PATIENTS AND METHODS

Patients received single daily doses of E7820 orally for 28 days in cycle 1, followed by a 7-day no-treatment period, after which time-uninterrupted daily dosing ensued. The starting dose of E7820 was 10 mg/d, which was increased to 20, 40, 70, 100, and 200 mg/d in cohorts of new patients.

RESULTS

Thirty-seven patients [21 male; median age 65 (40-82] were enrolled. At 100 mg/d, 1 patient experienced a DLT consisting of grade 3 neutropenia, thrombocytopenia, and elevated liver enzymes. At the 200-mg dose level, 2 patients experienced grade 4 thrombocytopenia and neutropenia. No partial or complete responses were observed; 8 patients had stable disease (≥ 4 months), including 5 patients with protracted stable disease exceeding 6 months. Mean time to maximum plasma concentration values ranged from 1 to 12 hours, whereas mean terminal half-life values ranged from 5.6 to 8.6 hours. Flow cytometric analysis of platelet integrin α-2 expression showed a sustained greater than 50% decrease beyond day 28 in 3 of 4 patients at 200 mg, whereas moderate (<30%) decreases were observed at 70- and 100-mg dose levels.

CONCLUSIONS

The recommended phase II dose of E7820 is 100 mg/d, based on a fasting schedule. E7820 downregulates integrin α-2 expression in surrogate tissues (platelets) and is associated with stable disease in a wide variety of heavily pretreated malignancies.

Phase I study of axitinib (AG-013736) in combination with gemcitabine in patients with advanced pancreatic cancer

PURPOSE

Axitinib (AG-013736), an oral, potent, and selective inhibitor of vascular endothelial growth factor (VEGF) receptors 1, 2, and 3, is under investigation for treatment of various solid tumors. The safety and pharmacokinetics of axitinib in combination with gemcitabine in patients with advanced pancreatic cancer was evaluated in the phase I portion of this trial. The randomized phase II portion was reported separately.

PATIENTS AND METHODS

Patients with advanced pancreatic cancer who had received no prior chemotherapy were eligible for this study. Pharmacokinetic profiles of the drugs were obtained on cycle (C) 1 day (D) 1 (gemcitabine alone 1,000 mg/m(2)), C1D14 (steady state, axitinib alone 5 mg twice daily [BID]), and C1D15 (gemcitabine plus steady-state axitinib). Adverse events were monitored weekly at the clinic.

RESULTS

Eight patients participated in the phase IB portion of the trial. Patients received gemcitabine on D1, D8, and D15 and continuous axitinib in a 28 day-cycle beginning C1D3. There was no dose-limiting toxicity. Common treatment-related adverse events included fatigue, diarrhea, dysphonia, and hypertension. Myelosuppression was similar to gemcitabine monotherapy. No apparent major pharmacokinetic interactions between gemcitabine and axitinib were observed. Of six patients evaluable for efficacy, three had confirmed partial responses.

CONCLUSIONS

Axitinib (5 mg BID) and gemcitabine (1,000 mg/m(2)) were well tolerated when administered together, without any pharmacokinetic interactions, and showed encouraging antitumor activity.

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.

Volociximab, a chimeric monoclonal antibody that specifically binds alpha5beta1 integrin: a phase I, pharmacokinetic, and biological correlative study

PURPOSE

This study aimed to assess the safety and feasibility of administering volociximab, a chimeric monoclonal antibody that specifically binds to alpha(5)beta(1) integrin, and to determine the pharmacokinetics, pharmacodynamics, and preliminary evidence of antitumor activity.

EXPERIMENTAL DESIGN

Patients with advanced solid malignancies were treated with escalating doses of volociximab i.v. administered over 60 minutes. Blood samples were assayed to determine plasma pharmacokinetic parameters, detect human antichimeric antibody formation, and determine the saturation of alpha5beta1 sites on peripheral blood monocytes.

RESULTS

Twenty-one patients received 223 infusions of volociximab at doses ranging from 0.5 to 15 mg/kg i.v. on days 1, 15, 22, 29, and 36; and weekly thereafter. Treatment was well tolerated, and dose-limiting toxicity was not identified over the range examined. Mild (grade 1 or 2), reversible fatigue was the principal toxicity of volociximab at the highest dose levels of 10 and 15 mg/kg. Nausea, fever, anorexia, headache, vomiting, and myalgias were mild and infrequent, and there was no hematologic toxicity. Volociximab had biexponential distribution; clearance was inversely related to increasing dose, and the half-life at 15 mg/kg was estimated as being 30 days. Three patients tested positive for anti-volociximab antibodies. Saturation of monocyte alpha5beta1 integrin sites was dose-dependent up to 15 mg/kg. There was one minor response (renal, 7 months) and one durable stable disease (melanoma, 14 months).

CONCLUSIONS

Volociximab can be safely administered at 15 mg/kg i.v. per week. The absence of severe toxicities and preliminary activity at the highest dose level warrants further disease-directed studies.

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.

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.

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, (90)Y-ibritumomab tiuxetan and (131)I-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.

Phase I and Pharmacokinetic Study of Sequences of the Rebeccamycin Analogue NSC 655649 and Cisplatin in Patients with Advanced Solid Tumors

PURPOSE

To evaluate the feasibility of administering NSC 655649, a water-soluble rebeccamycin analogue that inhibits both topoisomerases I and II, in combination with cisplatin (CDDP) in adults with solid malignancies. Major toxicologic and pharmacologic differences between the two sequences of drug administration were also assessed.

EXPERIMENTAL DESIGN

NSC 655649 was administered as a 60-minute i.v. infusion; CDDP was given i.v. before or after NSC 655649 on day 1. Each patient was treated with alternating drug sequences every 3 weeks; doses of each drug were escalated in separate cohorts of new patients. Sequential dose escalation of NSC 655649 or CDDP resulted in three dosage permutations of NSC 655649/CDDP: 440/50, 550/50, and 440/75 mg/m2. After the maximum tolerated dose level was determined, the feasibility of using granulocyte colony-stimulating factor to permit further dose escalation was explored.

RESULTS

Twenty patients were treated with 70 courses of NSC 655649/CDDP. Myelosuppression was the principal toxicity. The incidence of severe neutropenia, often associated with severe thrombocytopenia, was unacceptably high in minimally pretreated patients at the NSC 655649/CDDP dose level of 550/50 mg/m2 without and with granulocyte colony-stimulating factor. Major pharmacokinetic interactions between NSC 655649 and CDDP were not apparent. No relevant sequence-dependent differences in toxicity or pharmacokinetic variables occurred. Three patients had partial responses.

CONCLUSIONS

NSC 655649 and CDDP were well tolerated by minimally pretreated subjects at 440 and 50 mg/m2, respectively. Neither pharmacokinetic interactions between the agents nor sequence-dependent toxicologic or pharmacokinetic effects were apparent. The tolerance and preliminary activity observed with this combination suggest that disease-directed evaluations of the regimen are warranted.