What is Time to next treatment (TTNT) in Clinical Trials?

Time to Next Treatment (TTNT) is defined as the period from the start of the treatment to the start of the next line of treatment. 

In lower-level incurable diseases, TTNT is a meaningful endpoint for those needing multiple treatment interventions to prolong survival. Unlike most disease-related endpoints, TTNT includes the time process of treatment tolerance and patient compliance. 

TTNT becomes a measure of the duration of treatment effects, especially in primary cutaneous T-cell lymphoma. 

Although TTNT is useful, it serves as a surrogate marker for the duration of clinical benefits and needs validation before it can be used as an independent marker for assessing treatment efficacy.