Alternate designs for conduct and analysis of phase I cancer trials

Quality assessment of phase I dose-finding cancer trials: proposal of a checklist

BACKGROUND

Qualitative checklists for phase III trials have been proposed, to improve the reporting of such trials and to assess the validity of their results.

PURPOSE

Our objective was to develop such a scale for phase I cancer trials.

METHODS

From a review of existing guidelines and checklists for phase III clinical trials, a staff team was responsible for the first selection of items and the construction of the questionnaire. The proposed quality assessment measures were rated by the survey respondents comprised of phase I research clinicians and statisticians on a 4-point Likert scale. Selected items from the quantitative analysis of the questionnaires were reviewed by an expert team who was responsible for providing the final items list. This was then applied to 103 recently published cancer phase I trials.

RESULTS

Of the 48 initial items proposed by the staff team, 17 were selected from the quantitative analysis of the 99 participants' ratings. After qualitative analysis by the expert team, a 15-item checklist was derived, with 5 items related to trial objective, 5 to design, and 5 to analysis. The application to 103 recent journal articles on phase I cancer trials evaluating cytotoxic drugs showed on average the report of 10 items (range: 6-13) with 4 items reported in more than 95% of papers, while 2 were poorly reported.

LIMITATIONS

The response rate of participants was 20.7%.

CONCLUSIONS

A quality assessment checklist was developed for improved critical appraisal of the reporting of cytotoxic, dose-finding phase I oncology trials. This may be a first step toward a minimum standard of quality measures for all phase I clinical trial reports.

Experimental designs for phase I and phase I/II dose-finding studies

We review the rationale behind the statistical design of dose-finding studies as used in phase I and phase I/II clinical trials. We underline what the objectives of such dose-finding studies should be and why the widely used standard design fails to meet any of these objectives. The standard design is a "memoryless" design and we discuss how this impacts on practical behaviour. Designs introduced over the last two decades can be viewed as designs with memory and we discuss how these designs are superior to memoryless designs. By superior we mean that they require less patients overall, less patients to attain the maximum tolerated dose (MTD), and concentrate a higher percentage of patients at and near to the MTD. We reanalyse some recently published studies in order to provide support to our contention that markedly better results could have been achieved had a design with memory been used instead of a memoryless design.

Autologous bone marrow transplantation in the treatment of refractory systemic sclerosis: early results from a French multicentre phase I-II study

Haematopoietic stem cell transplantation (HSCT) has been proposed for refractory autoimmune diseases, including systemic sclerosis (SSc). A sequential Bayesian phase I-II clinical trial was conducted in SSc patients to assess the feasibility, the tolerance and the efficacy of autologous HSCT. Peripheral blood stem cells (PBSC) were collected using cyclophosphamide (4 g/m2) and recombinant human granulocyte colony-stimulating factor (5 micro g/kg/d) and reinfused after positive CD34+ selection. Conditioning used cyclophosphamide (200 mg/kg) or melphalan (140 mg/m2) according to cardiac function. The main end-point was the failure of the procedure, defined by failure of either PBSC mobilization, CD34+ selection or intensification procedure, or by procedure-related death. Among the 12 enrolled patients, three failures occurred: one PBSC mobilization, one CD34+ selection and one CD34+ intensification. Probability of graft failure was estimated at 0.286 (95% confidence interval: 0.095-0.54). Autologous PBSC (n = 10) or bone marrow (n = 1) transplantation was actually performed in 11 patients with one procedure-related death. Median time to neutrophil (> 0.5 x 10(9)/l) and platelet (> 25 x 10(9)/l) haematopoietic reconstitution was 12 and 10 d respectively. After 18 months (range 1-26), eight out of 11 patients have shown major or partial response. Non-myeloablative conditioning, followed by a T cell-depleted autologous PBSC or bone marrow transplantation, appears feasible with low toxicity in severe SSc with short-term clinical benefits.