End points in clinical trials in diffuse large B-cell lymphoma: time for more dialogue?

We observed lack of clarity and consistency in end point definitions of large randomized clinical trials in diffuse large B-cell lymphoma. These inconsistencies are such that trials might, in fact, address different clinical questions. They complicate interpretation of results, including comparisons across studies. Problems arise from different ways to account for events occurring after randomization including absence of improvement in disease status, treatment discontinuation or the initiation of new therapy. We call for more dialogue between stakeholders to define with clarity the questions of interest and corresponding end points. We illustrate that assessing different end point rules across a range of plausible patient journeys can be a powerful tool to facilitate such a discussion and contribute to better understanding of patient-relevant end points.

What is this article about? This article talks about the lack of clarity and consistency in the definitions of outcomes used in clinical trials that investigate new treatments for diffuse large B-cell lymphoma. This is mainly due to how these different outcome definitions handle events such as absence of improvement in disease status, treatment discontinuation or initiation of new treatment. The authors discuss how these inconsistencies make it hard to interpret the results of individual clinical trials and to compare results across clinical trials.Why is it important? Defining the above events and consequently defining outcomes affects what we can learn from the trials and can lead to different results. Some approaches may not reflect good and bad outcomes for patients appropriately. This makes it challenging for patients, physicians, health authorities and payors to understand the true benefit of treatments under investigation and which one is better.What are the key take-aways? This article serves as a call-to-action for more dialogue among all stakeholders involved in drug development and the decision-making process related to drug evaluations. There is an urgent need for clinical trials to be designed with more clarity and consistency on what is being measured so that relevant questions for patients and prescribing physicians are addressed. Understanding patient journeys will be key to successfully understand what truly matters to patients and how to measure the benefit of new treatments. Such discussions will contribute toward more clarity and consistency in the evaluation of new treatments.

A multicenter, open-label, Phase 1 study evaluating the safety and tolerability of pegaspargase in combination with gemcitabine in advanced metastatic solid tumors and lymphoma.

PURPOSE: To evaluate the maximum tolerated dose, safety profile, pharmacokinetics, and pharmacodynamics of pegaspargase (PEG-ASP) in combination with gemcitabine in patients with advanced metastatic solid tumors and lymphoma. METHODS: We conducted a multicenter, open label, nonrandomized, Phase 1 dose escalation study designed to evaluate up to 10 cohorts of patients with advanced or metastatic solid tumors and lymphoma. Seventeen patients were treated with of PEG-ASP in combination with gemcitabine. RESULTS: The study was terminated early because the doses for PEG-ASP suggested for de-escalation were predicted not to provide desired sustained asparaginase concentrations based on the analysis of treated patients.

Phase 1 evaluation of EZN-2208, a polyethylene glycol conjugate of SN38, in children adolescents and young adults with relapsed or refractory solid tumors.

BACKGROUND: EZN-2208 is a water-soluble PEGylated conjugate of the topoisomerase inhibitor SN38, the active metabolite of irinotecan. Compared to irinotecan, EZN-2208 has a prolonged half-life permitting extended exposure to SN38. EZN-2208 has demonstrated clinical tolerability and antitumor activity in adults with advanced solid tumors. This Phase 1 study evaluated the safety, pharmacokinetics, and preliminary antitumor activity of EZN-2208 in children with relapsed or refractory solid tumors. PROCEDURE: EZN-2208 was administered as a 1-hour intravenous infusion once every 21 days at five dose levels (12-30 mg/m(2) ). Filgrastim or pegfilgrastim was administered 24-48 hours after treatment with EZN-2208. The rolling-six design was used for dose determination. RESULTS: Thirty eligible patients (15 females; median [range] age 11.5 years [2-21 years]) were treated with EZN-2208. Dose-limiting diarrhea occurred in one patient receiving 16 mg/m(2) and dose-limiting dehydration was seen in one patient receiving 24 mg/m(2) . At dose levels above 16 mg/m(2) , Grade ≥3 myelosuppression was demonstrated in the majority of patients. Additional adverse events included nausea, vomiting, and fatigue. The maximum tolerated dose was identified as 24 mg/m(2) due to dose-limiting thrombocytopenia in two patients receiving 30 mg/m(2) . Two of nine patients with neuroblastoma who were evaluable for response had partial responses. Five patients (four with neuroblastoma) remained on study for ≥8 cycles. CONCLUSIONS: EZN-2208 was generally well-tolerated and was associated with clinical benefit in patients with neuroblastoma.

A phase I study of EZN-3042, a novel survivin messenger ribonucleic acid (mRNA) antagonist, administered in combination with chemotherapy in children with relapsed acute lymphoblastic leukemia (ALL): a report from the therapeutic advances in childhood leukemia and lymphoma (TACL) consortium.

To address the therapeutic challenges in childhood relapsed ALL, a phase 1 study combining a survivin mRNA antagonist, EZN-3042, with reinduction chemotherapy was developed for pediatric patients with second or greater bone marrow relapses of B-lymphoblastic leukemia. EZN-3042 was administered as a single agent on days -5 and -2 and then in combination with a 4-drug reinduction platform on days 8, 15, 22, and 29. Toxicity and the biological activity of EZN-3042 were assessed. Six patients were enrolled at dose level 1 (EZN-3042 2.5 mg/kg/dose). Two dose-limiting toxicities were observed: 1 patient developed a grade 3 γ-glutamyl transferase elevation and another patient developed a grade 3 gastrointestinal bleeding. Downmodulation of survivin mRNA and protein were assessed after single-agent dosing and decreased expression was observed in 2 of 5 patients with sufficient material for analysis. Although some biological activity was observed, the combination of EZN-3042 with intensive reinduction chemotherapy was not tolerated at a dose that led to consistent downregulation of survivin expression. The trial was terminated following the completion of dose level 1, after further clinical development of this agent was halted.

Randomized phase 2 study of pegylated SN-38 (EZN-2208) or irinotecan plus cetuximab in patients with advanced colorectal cancer.

BACKGROUND: Irinotecan is cytotoxic in patients with advanced colorectal cancer (CRC). SN-38 (10-hydroxy-7-ethyl-camptothecin) is the active metabolite of irinotecan. Attachment of polyethylene glycol (PEG) polymer chains (pegylation) to SN-38 (EZN-2208) increases the solubility, exposure, and half-life of SN-38. Preclinical studies demonstrated superior in vitro efficacy of EZN-2208 when it was tested in irinotecan-refractory human CRC cell lines. METHODS: Patients with metastatic or locally recurrent CRC who had previously received 5-flurouracil (5-FU), oxaliplatin, and irinotecan were assigned to receive EZN-2208 monotherapy (9 mg/m(2) on days 1, 8, and 15 every 28 days for patients with KRAS-mutant tumors only [arm A]), and patients with KRAS wild-type tumors were randomized (2:1) to receive either EZN-2208 plus cetuximab (400 mg/m(2) loading dose on day 1 followed by 250 mg/m(2) weekly starting on day 8 [arm B]) or irinotecan 125 mg/m(2) on days 1 and 8 every 21 days plus cetuximab at the same doses indicated above (arm C). RESULTS: The overall response rate and progression-free survival were 0% and 1.8 months, respectively, in arm A; 10.7% and 4.9 months (95% confidence interval [CI], 3.2-5.8 months), respectively, in arm B; and 14.3% and 3.7 months (95% CI, 2.1-5.8 months), respectively, in arm C. EZN-2208 was well tolerated in combination with cetuximab. No statistically significant difference in survival was observed between arm B (9.8 months; 95% CI, 7.2-11.2 months) and arm C (9.1 months; 95% CI, 6.0-13.0 months). CONCLUSIONS: EZN-2208, either as monotherapy or in combination with cetuximab, was well tolerated in patients with refractory CRC. Overall survival and progression-free survival were similar in the cetuximab plus irinotecan arm and the EZN-2208 arm.

Safety, pharmacokinetics, and activity of EZN-2208, a novel conjugate of polyethylene glycol and SN38, in patients with advanced malignancies.

BACKGROUND: EZN-2208 is a water-soluble, polyethylene glycol drug conjugate of SN38, which is the active moiety of irinotecan. In this study, the authors evaluated the tolerability, pharmacokinetics (PK), and activity of EZN-2208 in adult patients with advanced solid tumors. METHODS: Patients in sequential cohorts (3 + 3 design) received intravenous EZN-2208 at doses between 1.25 mg/m(2) and 25 mg/m(2) once every 21 days. RESULTS: Thirty-nine patients received EZN-2208. The median number of prior therapies was 2 (range, 0-10 prior therapies). Seventeen patients received prior irinotecan. Two maximum tolerated doses (MTDs) were defined: EZN-2208 with (16.5 mg/m(2)) and without (10 mg/m(2)) granulocyte-colony-stimulating factor (G-CSF). The dose-limiting toxicity (DLT) was febrile neutropenia. Two of 19 patients who were heterozygous for a polymorphism in the uridine diphosphate glucuronosyltransferase 1 family, polypeptide A1 (UGT1A1) gene (UGT1A1*28) developed DLTs (dose, 25 mg/m(2) with G-CSF), and 2 patients who were homozygous for UGT1A1*28 were treated without DLTs (dose, 5 mg/m(2)). PK analysis indicated a mean terminal half-life of 19.4 ± 3.4 hours. Sixteen patients (41%) achieved stable disease, including 6 of 39 patients (15%) who had stable disease that lasted ≥ 4 months. One patient with cholangiocarcinoma (no prior irinotecan) achieved a short-lived 32% tumor regression. Among 6 patients who had stable disease that lasted for ≥ 4 months, 3 had received prior irinotecan, and 1 had KRAS-positive colorectal cancer. CONCLUSIONS: EZN-2208 was well tolerated and produced stable disease that lasted for ≥ 4 months/unconfirmed partial responses in 7 of 39 heavily pretreated patients (18%) with advanced solid tumors, including those who had failed prior irinotecan therapy.

Pharmacokinetics of Nilotinib in Pediatric Patients with Philadelphia Chromosome-Positive Chronic Myeloid Leukemia or Acute Lymphoblastic Leukemia.

PURPOSE: We investigated nilotinib exposure in pediatric patients with chronic myeloid leukemia (CML) or Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) resistant to, relapsed on, refractory to, or intolerant of previous treatment. PATIENTS AND METHODS: Fifteen patients (aged 1-<18 years) with CML resistant to or intolerant of imatinib and/or dasatinib (n = 11) or Ph+ ALL relapsed on or refractory to standard therapy (n = 4) enrolled in this phase I study. Nilotinib (230 mg/m2 twice daily; equivalent to the adult 400-mg twice-daily dose) was administered orally in 12 or 24 cycles of 28 days. The primary objective was to characterize the pharmacokinetics of nilotinib in pediatric patients. RESULTS: The area under the concentration-time curve at steady state was slightly lower in pediatric patients versus adults (14,751.4 vs. 17,102.9 ng/h/mL); the geometric mean ratio (GMR; pediatric:adult) was 0.86 [90% confidence interval (CI), 0.70-1.06]. Body surface area-adjusted systemic clearance was slightly higher in pediatric versus adult patients (GMR, 1.30; 90% CI, 1.04-1.62). Nilotinib was generally well tolerated. The most common adverse events were headache, vomiting, increased blood bilirubin, and rash. Three patients with CML achieved major molecular response, and three with Ph+ ALL achieved complete remission. CONCLUSIONS: Nilotinib 230 mg/m2 twice daily in pediatric patients provided a pharmacokinetics and safety profile comparable with the adult reference dose; clinical activity was demonstrated in both CML and Ph+ ALL. This dose is recommended for further evaluation in pediatric patients. The safety profile was consistent with that in adults.

Association of mannose-binding lectin deficiency with acute invasive aspergillosis in immunocompromised patients.

BACKGROUND: Invasive aspergillosis is a devastating infection with attributable mortality of 40% despite antifungal therapy. In animal models of aspergillosis, deficiency of mannose-binding lectin (MBL), a pattern recognition receptor that activates complement, is a susceptibility factor. MBL deficiency occurs in 20%-30% of the population. We hypothesized that MBL deficiency may be a susceptibility factor for invasive aspergillosis in humans. METHODS: Serum MBL concentrations were measured by enzyme-linked immunosorbent assay in 65 patients with proven or probable acute invasive aspergillosis and 78 febrile immunocompromised control subjects. MBL concentrations and the frequency of MBL deficiency were compared. RESULTS: The median serum MBL level was significantly lower in patients with aspergillosis than in control subjects (281 ng/mL vs 835 ng/mL; P = .007). MBL deficiency (MBL concentration, <500 ng/mL) was significantly more common in patients with aspergillosis than control subjects (62% vs 32%; P < .001). Frequency of MBL deficiency was similar among patients with aspergillosis irrespective of response to antifungal therapy (P = .10). CONCLUSIONS: This study is the first, to our knowledge, to show an association between MBL deficiency and acute invasive aspergillosis in humans. Further study is required to investigate the causal nature of this association and to define whether diagnosis of MBL deficiency may identify immunocompromised patients at increased risk of invasive aspergillosis.

Clinical Pharmacokinetic and Pharmacodynamic Overview of Nilotinib, a Selective Tyrosine Kinase Inhibitor.

Nilotinib, an oral inhibitor of the tyrosine kinase activity of Abelson protein, is approved for the treatment of patients with newly diagnosed chronic myeloid leukemia (CML) in chronic phase and patients with CML in chronic phase or accelerated phase resistant or intolerant to prior therapies. This review describes the pharmacokinetic and pharmacodynamic data of nilotinib in patients with CML and in healthy volunteers. Nilotinib is rapidly absorbed, with a peak serum concentration approximately 3 hours after dosing. The area under the plasma drug concentration-time curve over 24 hours and the peak serum concentration of nilotinib were dose proportional from 50-400 mg once daily. The metabolism of nilotinib is primarily via hepatic cytochrome P450 (CYP) 3A4 according to in vitro studies. In the clinical setting, exposure to nilotinib was significantly reduced by the induction of CYP3A4 with rifampicin and significantly increased by the inhibition of CYP3A with ketoconazole. Additionally, nilotinib is a competitive inhibitor of CYP3A4/5, CYP2C8, CYP2C9, CYP2D6, and uridine diphosphate glucuronosyltransferase 1A1. The bioavailability of nilotinib is increased by up to 82% when given with a high-fat meal compared with fasted state. There is a positive correlation between the occurrences of all-grade total bilirubin elevations and the steady-state nilotinib trough concentrations. Fredericia method corrected QT interval change from baseline was observed to have a correlation with nilotinib exposure. No significant relationship between nilotinib exposure and major molecular response at 12 months was seen at therapeutic doses of nilotinib 300-400 mg, probably due to the narrow range of the doses investigated.

Celecoxib treatment alters the gene expression profile of normal colonic mucosa.

A clinical trial was recently conducted to evaluate the safety and efficacy of a selective inhibitor of cyclooxygenase-2 (celecoxib) in hereditary nonpolyposis colon cancer patients. In a randomized, placebo-controlled phase I/II multicenter trial, hereditary nonpolyposis colon cancer patients and gene carriers received either celecoxib at one of two doses or placebo. The goal was to evaluate the effects of these treatment arms on a number of endoscopic and tissue-based biomarker end points after 12 months of treatment. As part of this trial, we analyzed gene expression by cDNA array technology in normal descending (rectal) colonic mucosa of patients before and after treatment with celecoxib or placebo. We found that treatment of patients with celecoxib at recommended clinical doses (200 and 400 mg p.o. bid), in contrast to treatment with placebo, leads to changes in expression of >1,400 genes in the healthy colon, although in general, the magnitude of changes is <2-fold. Twenty-three of 25 pairs of colon biopsies taken before and after celecoxib treatment can be classified correctly by the pattern of gene expression in a leave-one-out cross-validation. Immune response, particularly T- and B-lymphocyte activation and early steps of inflammatory reaction, cell signaling and cell adhesion, response to stress, transforming growth factor-beta signaling, and regulation of apoptosis, are the main biological processes targeted by celecoxib as shown by overrepresentation analysis of the distribution of celecoxib-affected genes across Gene Ontology categories. Analysis of possible cumulative effects of celecoxib-induced changes in gene expression indicates that in healthy colon, celecoxib may suppress the immune response and early steps of inflammation, inhibit formation of focal contacts, and stimulate transforming growth factor-beta signaling.

Distinguishing right from left colon by the pattern of gene expression.

Distinct epidemiological and clinicopathological characteristics of colorectal carcinomas (CRCs) based on their anatomical location suggest different risk factors and pathways of transformation associated with proximal and distal colon carcinogenesis. These differences may reflect distinct biological characteristics of proximal and distal colonic mucosa, acquired in embryonic or postnatal development, that determine a differential response to uniformly distributed environmental factors. Alternatively, the differences in the epidemiology of proximal and distal CRCs could result from the presence of different procarcinogenic factors in the ascending versus descending colon, acting on cells with either similar or distinct biological characteristics. We applied cDNA microarray technology to explore the possibility that mucosal epithelium from adult proximal and distal colon can be distinguished by their pattern of gene expression. In addition, gene expression was studied in fetal (17-24 weeks gestation) proximal and distal colon. More than 1000 genes were expressed differentially in adult ascending versus descending colon, with 165 genes showing >2-fold and 49 genes showing >3-fold differences in expression. With almost complete concordance, biopsies of adult colonic epithelium can be correctly classified as proximal or distal by gene expression profile. Only 87 genes were expressed differently in ascending and descending fetal colon, indicating that, although anatomically relevant differences are already established in embryonic colon, additional changes in gene expression occur in postnatal development.

Phase I dose-escalation study of EZN-2208 (PEG-SN38), a novel conjugate of poly(ethylene) glycol and SN38, administered weekly in patients with advanced cancer.

PURPOSE: This study evaluated the tolerability, pharmacokinetics, and preliminary antitumor activity of EZN-2208, a water-soluble poly(ethylene) glycol conjugate of SN38. METHODS: Patients with advanced malignancies were enrolled in dose-escalating cohorts (3 + 3 design). EZN-2208 was administered as a 1-h intravenous infusion given weekly for 3 weeks per each 4-week cycle. Doses ranged from 1 to 12 mg/m(2). RESULTS: Forty-one patients received EZN-2208. All patients had received prior cancer therapy (median = 2, range = 1-11). Twenty patients (49 %) had received prior irinotecan, and one patient had received prior topotecan. One patient in the 9-mg/m(2) cohort had dose-limiting toxicity (grade 3 febrile neutropenia), and one patient in the 12-mg/m(2) cohort had grade 3 neutropenia that resulted in the inability to deliver the third dose of EZN-2208. The most commonly reported drug-related adverse events were nausea (51 %), diarrhea (46 %), fatigue (41 %), alopecia (29 %), neutropenia (24 %), and vomiting (22 %). Administration of EZN-2208 results in prolonged exposure to SN38. Stable disease, sometimes prolonged, was observed as best response. CONCLUSIONS: EZN-2208 has an acceptable safety profile in previously treated patients with advanced malignancies. The recommended phase II dose of EZN-2208 administered according to this schedule was 9 mg/m(2).