I just do not see anywhere dsmc could recommend anything other than stopping the trial as it relates to efficacy:
Potential DMC Responsibilities
4.4.1. Interim Monitoring
Most experience with DMCs has been in the setting of studies that address major outcomes such as mortality or serious irreversible morbidity. Although many such studies focus on short-term endpoints such as 30-day survival, other studies often use endpoints that require a substantial duration of follow-up after the intervention delivery has been completed. The need for monitoring in such
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Contains Nonbinding Recommendations
studies often extends beyond the time when individuals are treated, since trends in survival or other serious outcomes may not become evident until some time during the follow-up period. Thus, the DMC’s responsibility to monitor the study generally continues until the planned completion of follow-up, regardless of the duration of treatment.
4.4.1.1. Monitoring for Effectiveness
In studies with serious outcomes, all parties would wish that any major treatment advance be identified and made available as soon as possible. It is critical, however, that the study yield a valid and definitive result. Thus, tensions between ethical and scientific considerations may arise. Consider, for example, a placebo-controlled trial of a new product for a serious illness or condition for which there is no standard treatment. If the emerging data suggest that those receiving the treatment are doing better, one might expect that a DMC would consider whether the study should be terminated earlier than planned. Estimates of treatment effect, however, will be unstable at early points in a study, and the chance is substantial of observing a nominally statistically significant benefit (e.g., p<0.05) at one of multiple interim analyses during a study of an ineffective product (see Section 4.4.2). A DMC, guided by a pre-specified statistical monitoring plan acceptable to both the DMC and the study leadership, will generally be charged with recommending early termination on the basis of a positive result only when the data are truly compelling and the risk of a false positive conclusion is acceptably low.
A second type of consideration is whether the hypothesized benefit is likely ultimately to be achieved. If the interim data suggest that the new product is of no benefit—that is, there is no trend indicating superiority of the new product—or that accrual rates are too low or noncompliance too great to provide adequate power for identifying the specified benefit, a DMC may consider whether continuation of the study is futile and may recommend early termination on this basis. In this case, false negative conclusions are of concern; statistical procedures are available to guide such determinations
