A proposal for a new PhD level curriculum on quantitative methods for drug development

This paper provides an overview of "Improving Design, Evaluation and Analysis of early drug development Studies" (IDEAS), a European Commission-funded network bringing together leading academic institutions and small- to large-sized pharmaceutical companies to train a cohort of graduate-level medical statisticians. The network is composed of a diverse mix of public and private sector partners spread across Europe, which will host 14 early-stage researchers for 36 months. IDEAS training activities are composed of a well-rounded mixture of specialist methodological components and generic transferable skills. Particular attention is paid to fostering collaborations between researchers and supervisors, which span academia and the private sector. Within this paper, we review existing medical statistics programmes (MSc and PhD) and highlight the training they provide on skills relevant to drug development. Motivated by this review and our experiences with the IDEAS project, we propose a concept for a joint, harmonised European PhD programme to train statisticians in quantitative methods for drug development.

An investigation on performance of Significance Analysis of Microarray (SAM) for the comparisons of several treatments with one control in the presence of small-variance genes

One of multiple testing problems in drug finding experiments is the comparison of several treatments with one control. In this paper we discuss a particular situation of such an experiment, i.e., a microarray setting, where the many-to-one comparisons need to be addressed for thousands of genes simultaneously. For a gene-specific analysis, Dunnett's single step procedure is considered within gene tests, while the FDR controlling procedures such as Significance Analysis of Microarrays (SAM) and Benjamini and Hochberg (BH) False Discovery Rate (FDR) adjustment are applied to control the error rate across genes. The method is applied to a microarray experiment with four treatment groups (three microarrays in each group) and 16,998 genes. Simulation studies are conducted to investigate the performance of the SAM method and the BH-FDR procedure with regard to controlling the FDR, and to investigate the effect of small-variance genes on the FDR in the SAM procedure.

On the Use of Historical Control Data in Pre-Clinical Safety Studies

A number of methods to formally incorporate historical control information in pre-clinical safety evaluation studies have been proposed in literature. However, it remains unclear when one should use historical data. Focusing on the logistic-normal model, we investigate situations where historical studies may prove to be useful. Aspects of estimation (precision and bias) and testing (power) for treatment effect are investigated under different conditions such as the number of historical control studies, the degree of homogeneity amongst them, the level of treatment effect and different control rates. The possibility to use a selected subset of historical control studies is also explored.

Spatial determination of successive spikes in the isolated cat duodenum

In seven isolated segments of the feline duodenum, the timings of all spikes and the locations of all spike patches that occurred after 12-16 successive slow waves were analysed. Simultaneous recordings were performed during 1-min periods using 240 extracellular electrodes (24 x 10 array; interelectrode distance 2 mm) positioned onto the serosal surface. In all seven preparations, spikes always occurred during the first half of the slow wave cycle. From preparation to preparation, and within 1-min periods in each preparation, there was limited variation in the spike-spike intervals, in the times between the spikes and the preceding slow wave and in the number of spikes at each electrode site. In contrast, the number of electrode sites that recorded spikes and the number of spike patches both showed great variability between preparations and sometimes within a single preparation. In addition, the location of spikes and spike patches was not random but was significantly concentrated in certain areas, often located along the anti-mesenteric border, while other sites showed little or no spike activity. In conclusion, spikes and spike patches tend to occur significantly in some areas and not in others. This spatial heterogeneity will play a role in intestinal motility.

Individual patient-versus literature-based meta-analysis of survival data: time to event and event rate at a particular time can make a difference, an example based on head and neck cancer

The objective of this study is to compare the results of an individual patient-based and a literature-based meta-analysis in chemotherapy in head and neck cancer and to identify the sources of difference. For all head and neck cancer randomized controlled clinical trials comparing chemotherapy and loco-regional treatment with loco-regional treatment alone, both the literature data and the individual patient data are retrieved and meta-analyses performed and compared. Only survival data are used as outcome, although both time to death and mortality at specific time points are considered in different analyses. There are substantial differences between the individual patient-based and the literature-based meta-analyses. The most important reason for the differing results is that the individual patient-based meta-analysis is based on a time to event analysis, whereas the literature-based meta-analysis is based on mortality at a specific time point. Mortality can change substantially with follow-up time. The absolute survival differences in the case study, for instance, increase from 2.6% at 2 years to 5.6% at 5 years.

Application of the International Prognostic Scoring System for myelodysplastic syndromes

BACKGROUND

In March 1997 an international workshop introduced a new International Prognostic Scoring System (IPSS) for MDS. The goal of the present study was to apply the IPSS to a large group of MDS patients from one centre and to compare it to the FAB-classification.

PATIENTS

One hundred eighty-four MDS patients were included on the basis of similar criteria as used by the workshop but some of them (30) received AML-type therapy.

RESULTS

The IPSS separated our patients into distinctive prognostic subgroups (P = 0.0001). Median survival was respectively 6.5, 2.6, 1.3 and 0.75 years for the low-risk (22% of patients), the intermediate-1-risk (INT-1) (46%), the intermediate-2-risk (INT-2) (25%) and the high-risk group (7%). The IPSS also discriminated within each of the FAB-categories: RA patients (58 patients) were present in low-risk, INT-1-risk and INT-2-risk subgroups, RARS patients (23) were separated into low-risk and INT-1-risk subgroups. RAEB patients (53) were distributed predominantly between INT-1-risk and INT-2-risk groups, RAEB-t patients (23) between INT-2-risk and high-risk subgroups. CMML patients (27) were present in the low-risk, the INT-1-risk and the INT-2-risk group.

CONCLUSIONS

Our results confirm the effectiveness of the IPSS in predicting clinical outcome in MDS patients and indicate that it is an improved method compared to the FAB-classification.

Individual patient data meta-analysis in cancer

As in many areas of health care, treatments for cancer may differ only moderately in their effects on major end points, such as death. But, such differences are worth knowing about, particularly in common diseases in which they could represent a substantial benefit to public health. Large-scale randomized evidence allows moderate differences to be investigated reliably, and one way to achieve this is by meta-analyses of updated and centrally collected individual patient data from all relevant trials. This paper illustrates why this form of research can often be important in cancer. It also offers the first list of such projects, as a source of information on current and past research in this area.

Overview of randomized perioperative polychemotherapy trials in women with early-stage breast cancer

PURPOSE

To determine whether perioperative polychemotherapy (PeCT) can significantly prolong the overall survival of women with early-stage breast cancer.

METHODS

A meta-analysis that used updated individual patient data from all available randomized trials of PeCT, both published and unpublished, was conducted. Data on 6,093 patients (1,124 deaths and 1,912 recurrences) from five clinical trials were available (median follow-up duration, 5.3 years; maximum, 11.3 years).

RESULTS

No significant effect of PeCT on overall survival was observed. However, patients who received PeCT had a significantly longer disease-free survival (hazards ratio [HR], 0.89; 95% confidence interval [CI], 0.82 to 0.98; P = .02). Time to local recurrence was significantly prolonged in the PeCT arm (HR, 0.68; 95% CI, 0.58 to 0.80; P < .0001). Likewise, there was a borderline significant difference in favor of PeCT in terms of time to distant metastases (HR, 0.90; 95% CI, 0.81 to 1.00; P = .05). Subgroup analyses suggest that node-negative women benefited the most from treatment.

CONCLUSION

At present, there is no evidence that PeCT is able to prolong overall survival in patients with early-stage breast cancer; however, further follow-up evaluation is required. PeCT significantly prolongs disease-free survival, especially in node-negative women, which emphasizes once more the need for clinical trials in this subgroup.

Persistent improved results after adding vincristine and bleomycin to a cyclophosphamide/hydroxorubicin/Vm-26/prednisone combination (CHVmP) in stage III-IV intermediate- and high-grade non-Hodgkin's lymphoma. The EORTC Lymphoma Cooperative Group

CHOP has been and still is regarded by many as the 'standard' treatment of advanced non-Hodgkin's lymphoma. In 1980 the EORTC Lymphoma Cooperative Group started a study to evaluate the addition of vincristine and bleomycin to its standard four-drug combination chemotherapy, CHVmP (cyclophosphamide, hydroxorubicin, Vm-26, prednisone). Eligible patients were stage III or IV, intermediate- to high-grade non-Hodgkin's lymphoma (Working Formulation E-I). One-hundred-eighty-nine patients were entered, of whom 140 were eligible and evaluable. A previous report showed an improved response rate and failure-free survival (FFS) and overall survival for the combination CHVmP-VB. At ten years, the outcome still favors the addition of vincristine and bleomycin. The FFS was 34% vs. 23% and the overall survival 34% vs 22%. This difference was mainly due to a difference in CR rate (74% vs. 49%), Relapse-free survival for patients reaching a CR was the same in both arms. When the patients were grouped according to the International Prognostic Factor Index, no statistically significant difference could be observed in favor of one treatment within either group. This trial clearly demonstrates the benefit gained by the addition of vincristine and bleomycin to 'standard' chemotherapy for intermediate and high-grade non-Hodgkin's lymphoma.

A combined analysis of European Organization for Research and Treatment of Cancer, and Medical Research Council randomized clinical trials for the prophylactic treatment of stage TaT1 bladder cancer. European Organization for Research and Treatment of Cancer Genitourinary Tract Cancer Cooperative Group and the Medical Research Council Working Party on Superficial Bladder Cancer

PURPOSE

The use of prophylactic agents after primary resection can decrease the incidence of tumor recurrence in patients with stage TaT1 bladder cancer. However, the long-term impact on progression to muscle invasive disease as well as on duration of survival is unknown. A combined analysis of individual patient data from previously performed European Organization for Research and Treatment of Cancer (EORTC) and Medical Research Council (MRC) randomized clinical trials was done in an attempt to answer these crucial questions. We compared immediate versus no adjuvant prophylactic treatment after transurethral resection with respect to disease-free interval, time to progression to muscle invasive disease, time to appearance of distant metastases, duration of survival and progression-free survival.

MATERIALS AND METHODS

All EORTC and MRC prophylactic, randomized phase III trials with primary or recurrent, stage TaT1 transitional cell bladder cancer that compared transurethral resection alone or with adjuvant prophylactic treatment were included in the study. Four EORTC and 2 MRC trials using intravesical chemotherapy or oral agents and including a total of 2,535 patients were studied.

RESULTS

A statistically significant effect of adjuvant treatment over no adjuvant treatment was found in terms of the duration of the disease-free interval (p < 0.01). No clear advantage of adjuvant treatment was shown with respect to progression to invasive disease, time to appearance of distant metastases or duration of survival and progression-free survival. Median survival followup was 7.8 years.

CONCLUSIONS

Despite prologation of the disease-free-interval adjuvant treatment has no apparent long-term impact on the evolution of stage TaTi bladder cancer.

Clinical analysis of 670 cases in two trials of the European Organization for the Research and Treatment of Cancer Lymphoma Cooperative Group subtyped according to the Revised European-American Classification of Lymphoid Neoplasms: a comparison with the Working Formulation

In the Working Formulation (WF), non-Hodgkin's lymphomas (NHL) are grouped according to their clinical behavior. These disorders are listed as entities defined by morphology, phenotype, and cytogenetics in the proposed Revised European-American Classification of Lymphoid Neoplasms (REAL), the clinical relevance of which is still debated. We analyzed 670 NHL cases included in two randomized clinical trials (EORTC 20855 WF-intermediate/high-grade and 20856 WF-low-grade malignancy) with histologic material available for review. Based on hematoxylin-eosin-stained sections, 77% of cases could be subtyped. Immunophenotyping was considered to be mandatory only in diagnosing T-cell lymphoma and anaplastic large-cell lymphoma. Of 522 cases subtyped, 11% were mantle cell lymphoma (MCL), 5% were marginal zone B-cell lymphoma (MZBCL), 46% were follicle center lymphoma, and 32% were diffuse large B-cell lymphoma. Statistical analysis and comparisons between classifications were made only within each trial and treatment group. MCL and MZBCL were characterized by a shorter median survival (3.4 and 4.1 years, respectively) in comparison with low- and intermediate-grade WF groups (> 9.3 and 5.8 years, respectively). In terms of progression-free survival, MCL showed a behavior similar to the low-grade group, with frequent relapses. Follicle center cell lymphomas behaved as low-grade lymphomas as defined by the WF and diffuse large B-cell lymphomas as the WF-intermediate grade group. Because several NHL entities have a clinical behavior of their own, their recognition by the REAL classification offers clinicians additional information that is not obtained when the WF is used.

Efficacy of four different regimens in 64 mantle-cell lymphoma cases: clinicopathologic comparison with 498 other non-Hodgkin's lymphoma subtypes. European Organization for the Research and Treatment of Cancer Lymphoma Cooperative Group

PURPOSE

Before recognizing mantle-cell lymphoma (MCL) as a distinct entity, these patients were grouped into low-grade (LG) or intermediate-/high-grade categories (IGHG) according to the Working Formulation and received various therapies. This was a unique opportunity to evaluate characteristics, behavior, response to treatment, and outcome of patients with MCL from two phase III trials conducted by the European Organization for the Research and Treatment of Cancer (EORTC): EORTC 20855 IGHG and EORTC 20856 LG.

PATIENTS AND METHODS

After histologic review, 64 diagnosed MCL patients (29 IGHG and 35 LG) were compared with other patients in their respective trials. In the IGHG group, patients received cyclophosphamide, doxorubicin, teniposide (VM26), prednisone, vincristine, and bleomycin (CHVmP-VB) or modified doxorubicin, cyclophosphamide, etoposide (VP 16), mechlorethamine, vincristine, procarbazine, and prednisone (ProMACE-MOPP). In the LG group, after receiving cyclophosphamide, vincristine, and prednisone (CVP) induction, patients were randomized between maintenance treatment with interferon alfa-2a (IFN) or no further treatment.

RESULTS

MCL patients compared with IGHG subtypes showed a similar overall survival and response rate, but shorter duration of response and progression-free survival. Comparing with LG patients, their response rate, duration of response, and progression-free survival showed no difference, while their overall survival was nearly twice shorter. MCL patients treated with CHVmP-VB had the longest survival. No treatment showed any significant improvement in terms of progression-free survival.

CONCLUSION

These data confirm that MCL represents a clinicopathologic entity. In terms of survival, it behaves like IGHG subtypes, while in terms of progression-free survival, it behaves like LG lymphoma. It is still not clear which first-line treatment offers patients with MCL the best chance to obtain both a complete response (CR) and a long-term survival.