DOI: 10.5061/dryad.xd2547dpb
title: A multi-laboratory preclinical trial to assess treatment candidates for acute ischemic stroke

description: Human diseases may be modeled in animals to allow preclinical assessment
 of putative new clinical interventions. Recent, highly publicized failures
 of large clinical trials called into question the rigor, design, and value
 of preclinical assessment. We established the Stroke Preclinical
 Assessment Network (SPAN) to design and implement a randomized,
 controlled, blinded, multi-laboratory network for the rigorous assessment
 of candidate stroke treatments combined with intravascular thrombectomy.
 Futility boundaries in a Multi-Arm Multi-Stage statistical design aimed to
 exclude less effective interventions, and efficacy boundaries allowed
 early declaration of success after each of four sequential stages. Six
 independent research laboratories performed a standard focal cerebral
 ischemic insult in five animal models that included equal numbers of males
 and females: young mice, young rats, aging mice, mice with diet-induced
 obesity, and spontaneously hypertensive rats. The laboratories adhered to
 a common protocol and efficiently enrolled 2,615 animals with full data
 completion and comprehensive animal tracking. SPAN successfully
 implemented treatment masking, randomization, pre-randomization inclusion
 and exclusion criteria, and blinded assessment of outcomes. The
 SPAN design and infrastructure provide an effective approach that could be
 used in similar preclinical, multi-laboratory studies in other disease
 areas, and should help improve reproducibility in translational science.
description: SPAN consists of six research laboratories to conduct preclinical
 stroke modeling and a coordinating center to mask drugs, conduct
 centralized randomization, assess blinded outcomes, collect data, and
 perform statistics. The aim of SPAN was to determine whether such rigor is
 feasible and practical on a large scale in a multi-laboratory controlled,
 randomized preclinical study of six investigator-initiated putative
 interventions for acute ischemic stroke, selected through a rigorous
 NIH-peer review. Here we report the primary results of SPAN.
description: Tables contain the results of the corner test and the MR imaging
 organized by subject ID. Treatment group data is available in the
 feasibility file. These are contained in the following files:
 dt_feasibility_stm_paper
 2023-08-21<br>dt_outcome_corner_stm_paper
 2023-08-21<br>dt_outcome_mri_stm_paper
 2023-08-21<br>report_stm_paper 2023-07-29 The
 first 3 files are Excel files that contain data listings in tab 1 and data
 definition dictionary in tab 2. The treatment group variables can be found
 in the first file and applied to the remaining files by matching on the
 animal identity variable "enro_animal_id. The variable
 'txas_tx_group' contains a code that gives the treatment group
 to which the subject was assigned. The variable
 'txas_tx_group_actual' gives a code for the treatment group
 actually received. The corresponding drug treatment names can be found in
 tab 2 and in the main paper itself. The final html file is a report used
 to define the various study populations, including  the enrolled
 (pop_enro), the inelegible to be randomized, the intention to treat
 (pop_itt), the excluded animals, the procedural dropouts, the modified
 intention to treat (pop_mitt), the partial treatments, the per protocol
 treated animals, and the loss to followup (died) animals. 
description: A multi-laboratory preclinical trial to assess treatment candidates for
 acute ischemic stroke --- All data needed for the graphs published in
 Science Translational Medicine are provided. ## Description of the data
 and file structure Tables contain the results of the corner test, the MR
 imaging organized by subject ID. Treatment group data is available in the
 feasibility file. These are contained in the following files:
 dt\_feasibility\_stm\_paper\_2023-08-21.xls
 dt\_outcome\_corner\_stm\_paper\_2023-08-21.xls
 dt\_outcome\_mri\_stm\_paper 2023-08-21.xls
 report\_stm\_paper\_2023-07-29.html The first 3 files are Excel files that
 contain data listings in tab 1 and data definition dictionay in tab 2. The
 treatment group variables can be found in the first file and applied to
 the remaining files by matching on the animal identity variable
 'enro\_animal\_id'. The variable 'txas\_tx\_group'
 contains a code that gives the treatment group to which the subject was
 assigned. The variable 'txas\_tx\_group\_actual' gives a code
 for the treatment group actually recieved. The corresponding drug
 treatment names can be found in tab 2 and in the main paper itself. The
 final html file is a report used to define the various study populations,
 including the enrolled (pop\_enro), the inelegible to be randomized, the
 intention to treat (pop\_itt), the excluded animals, the procedural
 dropouts, the modified intention to treat (pop\_mitt), the partial
 treatments, the per protocol treated animals, and the loss to followup
 (died) animals. ## Sharing/Access information Links to other publicly
 accessible locations of the data: www.spannetwork.org is a repository of
 all SPAN SOPs ## Code/Software (Citations and figures can be found in the
 SPAN publication) SPAN selected a recently developed MAMS design as it is
 more efficient than multiple individual trials. Validated, user-friendly
 MAMS R-code has been published (56) based on a generalized Dunnett’s
 procedure (33). SPAN implemented the MAMS design with four stages using
 predefined futility and efficacy boundaries( 33). Stages 1 – 3 ended with
 planned interim analyses performed after 25, 50 and 75% recruitment and
 one final analysis of the entire dataset after Stage 4. The Statistical
 Analysis Plans (see Supplemental Material) provide a detailed description
 of the planned analysis for each endpoint (30). The primary outcome used
 in the MAMS was the 30-day corner test. To estimate needed sample size,
 simulations were performed using the MAMS R-package (92). From prior
 reports of the corner test in aged mice, we estimated mean of 0.55 and
 standard deviation (SD) of 0.262 turning index (left turns/total turns)
 for the control arm(47). We inflated the estimated standard deviation to
 1.048 as a conservative assumption to account for probable variability
 among SPAN research laboratories. The power of 90% was calculated under
 the least favorable configuration, which was defined as the probability of
 rejecting only one null hypothesis in any stage(93). Total sample size was
 then adjusted assuming 10% animal death over 30 days. At the end of each
 stage, an interim analysis of the primary outcome was performed that
 included all subjects up to that analysis. Each treatment was compared to
 the appropriate control group (pooled IV/IP or RIC sham), adjusting for
 laboratory, sex, baseline corner test index, animal model (stages 2-4) and
 whether the subjects remained under anesthesia during MCA occlusion (Stage
 1 only). Stopping rules included an estimated treatment effect size
 ((intervention – control)/sd) greater than an upper limit of 50% (change
 of 0.5 x 0.55 = 0.275) and less than a lower limit of 6% (change 0.06 x
 0.55 = 0.033) treatment effect size.” The projected boundaries at each
 interim analysis comprise a ‘triangle’ of upper and lower criteria for the
 five drug treatments compared against a pooled IV and IP control group
 (Fig. 3C). The RIC intervention was compared against the RIC sham group
 (Fig. 3D). The Steering Committee reviewed each interim analysis to decide
 which models to use and which interventions to continue in the next stage.
 At the end of Stage 3, the SC decided to study the one remaining
 intervention in young rats since all prior testing had been done in mice,
 other than SHRs. The Steering Committee making these decisions remained
 blinded to the treatment arm identity throughout all four stages.