Bioequivalence and Bioavailability Forum

Sundar.M ☆ India, 2018-09-27 13:11 (2031 d 23:09 ago) Posting: # 19330 Views: 3,440	RSABE - Sequence [RSABE / ABEL] Post reply
	Dear all, What would be the advantages/disadvantages of following 6 sequences (TRR, RTR, RRT, RTT, TRT and TTR) in a RSABE design, instead of 3 sequences as per FDA recommendations. Your comments are highly appreciated. Thanks Sundar. M

Helmut
★★★

Vienna, Austria,
2018-09-28 15:15
(2030 d 21:05 ago)

@ Sundar.M
Posting: # 19337
Views: 2,895

Suggested: TRT|RTR

Post reply

Hi Sundar,

❝ […] advantages/disadvantages of following 6 sequences (TRR, RTR, RRT, RTT, TRT and TTR) in a RSABE design, instead of 3 sequences as per FDA recommendations.

Advantages

Additionally to the estimate of CV_wR you get the one of CV_wT (good to know esp. if your study is a pilot and you want to design a pivotal study where CV_wR ≠ CV_wT). In the partial replicate you have to assume that CV_wR = CV_wT.
If s_wR <0.294 (only ABE acceptable) no convergence issues in the mixed-effects model with the FDA’s covariance-specification.

Disadvantages

Sample size is a multiple of six (instead of three in the partial replicate and two in the three-period full replicate).
Design currently not implemented in PowerTOST’s function sampleN.RSABE().

If you want to kill two birds with one stone I recommend the three-period two-sequence full replicate design (TRT | RTR) instead.

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Helmut Schütz

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Sundar.M ☆ India, 2018-09-28 15:36 (2030 d 20:44 ago) @ Helmut Posting: # 19338 Views: 2,712	Suggested: TRT\|RTR Post reply
	Thank you HS!

RSABE - Sequence [RSABE / ABEL]

Suggested: TRT|RTR

Suggested: TRT|RTR