Table 2. Likelihood-ratios and decision rules for ‘3+3’ and mTPI designs (per dose level) for scenario B.
| (B) H1: p=0.30 vs H2: p=0.05 | ||||||
|---|---|---|---|---|---|---|
|
| ||||||
| DLT(n)a | ‘3+3’ rule | mTPI ruleb | L(p2)/L(p1) | Evidencec | ||
|
| ||||||
| k=1 | k=2 | k=4 | ||||
| 0(3) | acceptable (E) | acceptable (E) | LR=2.50 | acceptable | acceptable | weak |
| 0(3)+0(3) | acceptable (E) | acceptable (E) | LR=6.25 | acceptable | acceptable | acceptable |
| 1(3)+0(3) | acceptable (E) | acceptable (S) | LR=0.77 | toxic | weak | weak |
| 2(3) | toxic (D) | toxic (D) | LR=0.04 | toxic | toxic | toxic |
| 3(3) | toxic (D) | toxic (D) | LR=0.001 | toxic | toxic | toxic |
| 1(3)+1(3) | toxic (D) | acceptable (S) | LR=0.09 | toxic | toxic | toxic |
| 1(3)+2(3) | toxic (D) | toxic (D) | LR=0.01 | toxic | toxic | toxic |
| 1(3)+3(3) | toxic (D) | toxic (D) | LR=0.001 | toxic | toxic | toxic |
Abbreviations: D: de-escalation; S: stay at same dose; E: escalation;
a
Dose limiting toxicities (cohort size)
b
mTPI: modified toxicity probability interval with pT = 0.175 and ε1= ε2=0.125
c
Acceptable: LR ≥ k; Toxic: LR ≤ 1 / k; Weak evidence (favors neither hypothesis): 1 / k < LR < k