Patients (pts) understanding of phase II trial designs and informed consent (IC)

Abstract

6011 Background: Phase II trials determine disease-specific activity of new agents. Standard phase II designs enroll initial cohorts, and the trial is terminated if all subjects are non-responders (NR). Due to ethical and scientific concerns, it is difficult to know if available NR information should be part of subject IC. Thus, we sought pts' understanding of the design and goals of phase II trials, experiences with IC, and interest in NR information. Methods: We conducted semi-structured interviews of cancer pts who recently enrolled in phase II trials at our institution. Results: Fifty-two of 54 consecutive pts agreed to be interviewed: 73% male, median age 58 (35–83), 77% white, 56% with some college. Patients reported physician phase II goals as: therapeutic benefit short of cure (60%), scientific (25%), cure/remission (20%). Patients own goals were prolongation of life (38%), therapeutic benefit short of cure (37%), cure/remission (23%). With regard to IC, 85% said they were told that advancement of scientific knowledge was an aspect of the trial, 79% said they were told they could stop treatment at any time, and 96% said they were informed of possible side effects; 73% said they were well informed of other options. However, only 50% of these pts reported they were offered non-experimental therapy, 32% no chemotherapy, and 12% palliative therapy. When asked about their understanding of the principal purpose of a phase II trial, 48% responded that it was therapeutic benefit short of cure, 40% advancement of scientific knowledge, 24% disease cure. Patients were also asked to define a threshold number (T) of NR they would be willing to accept before refusing enrollment. A majority (72%) was able to define a T: median 6.5 (1–99); and of these, 72% responded with a T that was <14 (cohort size required to detect a 20% RR). Seventy-four percent said they would want NR information before consenting to treatment; and 83% of these thought this information should be in the written consent form. Conclusions: Our data suggest that pts may not be adequately informed of alternatives to phase II trials and that disclosure of prior NR information is important to pts and may impact enrollment decisions. No significant financial relationships to disclose.