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ABBY: A phase 2 randomized trial of crenezumab in mild to moderate Alzheimer disease
Cummings JL, Cohen S, van Dyck CH, Brody M, Curtis C, Cho W, Ward M, Friesenhahn M et al.. Neurology, 2018-04-25
Topic: Amyloid, tau and blood-test diagnosis
Objective To evaluate the safety and efficacy of crenezumab in patients with mild to moderate Alzheimer disease (AD). Methods In this phase 2 trial, 431 patients with mild to moderate AD 50 to 80 years of age were randomized 2:1 (crenezumab:placebo). Patients received low-dose subcutaneous crenezumab 300 mg or placebo every 2 weeks (n = 184) or high-dose intravenous crenezumab 15 mg/kg or placebo every 4 weeks (n = 247) for 68 weeks. Primary outcome measures were change in Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog12) and Clinical Dementia Rating-Sum of Boxes scores from baseline to week 73. Results The primary and secondary endpoints were not met. In an exploratory post hoc analysis, a reduction in decline on the ADAS-Cog12 was observed in the high-dose group. Separation from the placebo group on the ADAS-Cog12 was greatest in the milder subsets of AD patients and reached statistical significance in the group with Mini-Mental State Examination scores of 22 to 26. In both groups, there was a significant increase in CSF β-amyloid 1-42 levels that correlated with crenezumab CSF levels. The overall rate of adverse events was balanced between groups. One case of amyloid-related imaging abnormalities indicative of vasogenic edema or effusions was reported. Conclusions Although prespecified criteria for testing treatment effects were not met, these data suggest a potential treatment effect in patients with mild AD treated with high-dose crenezumab. Together with the safety profile for crenezumab, these data support the exploration of crenezumab treatment at even higher doses in patients with early AD. Clinicaltrialsgov identifier NCT 01343966. Classification of evidence This study provides Class II evidence that, for people with AD, crenezumab does not significantly improve cognition or function at 18 months. The study is rated Class II because <80% of enrolled patients completed the study.
Key findings
- Results The primary and secondary endpoints were not met.
- In both groups, there was a significant increase in CSF β-amyloid 1-42 levels that correlated with crenezumab CSF levels.
- The overall rate of adverse events was balanced between groups.
- Classification of evidence This study provides Class II evidence that, for people with AD, crenezumab does not significantly improve cognition or function at 18 months.
Why it matters
In this phase 2 trial, crenezumab did not meet its primary or secondary endpoints for cognition or function. A post hoc analysis suggested reduced decline on one cognitive measure in the high-dose group and in milder patients, but this was not a prespecified result.
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Study details
- Study designclinical trial
- Participants184
- Evidence strengthHigh
How this study scored 74/100
Published in a leading specialty journal, and it is a mid-stage phase 2 trial. Scored zero for effect reported because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 9 / 10 | Tier 2 — leading specialty journal (Neurology) |
| Journal's citation record | 4 / 4 | Neurology: journal h-index 525 (OpenAlex, 2026-10-29) |
| Study design | 8 / 12 | A mid-stage phase 2 trial (from PubMed type “Clinical Trial, Phase II”) |
| Strength of evidence | 5 / 5 | Rated “high” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 2 / 5 | 2018 — within 10 year(s) of the newest study here |
| Sample size | 2 / 4 | 184 participants |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 3 / 3 | Studied in people (participant count stated) |
| Randomised / blinded | 1 / 2 | Randomised (as stated in the record) |
| Times cited | 5 / 7 | Cited 253 times (OpenAlex, 2026-10-10) |
| Citations per year | 4 / 5 | 25.3 citations a year over 10 year(s) since 2018 |
| Impact for its field and year | 4 / 6 | Cited 18.9× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 3 / 6 | Cited by 15 other studies in this library |
| Still being cited | 3 / 4 | Cited 62 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 3 / 4 | Last-listed author Robert H. Paul: h-index 86 (OpenAlex, whole career) |
| Institution's track record | 2 / 3 | Yale University: institution h-index 1,927 (OpenAlex) |
| Multi-centre collaboration | 2 / 3 | OpenAlex lists 6 institution(s) in 1 country |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 29695589) |
| Free to read | 2 / 2 | Free to read |
| Total | 74 / 100 | — |
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Read the original
Full text: free to read — OpenAlex lists this copy as free to read: the link above (checked 6 Feb 1020).
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Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. The record's author list ends in “et al.”, so not every author is named. Check the citation against the original before you use it.
APA 7th
Cummings, J. L., Cohen, S., van Dyck, C. H., Brody, M., Curtis, C., Cho, W., et al. (2018). ABBY: A phase 2 randomized trial of crenezumab in mild to moderate Alzheimer disease. Neurology. https://doi.org/10.1212/wnl.0000000000005550
Vancouver
Cummings JL, Cohen S, van Dyck CH, Brody M, Curtis C, Cho W, et al. ABBY: A phase 2 randomized trial of crenezumab in mild to moderate Alzheimer disease. Neurology. 2018. doi:10.1212/wnl.0000000000005550. PMID: 29695589.
BibTeX
@article{cummings2018-29695589,
author = {Cummings, J. L. and Cohen, S. and van Dyck, C. H. and Brody, M. and Curtis, C. and Cho, W. and Ward, M. and Friesenhahn, M. and others},
title = {{ABBY: A phase 2 randomized trial of crenezumab in mild to moderate Alzheimer disease}},
journal = {Neurology},
year = {2018},
doi = {10.1212/wnl.0000000000005550},
pmid = {29695589},
url = {https://doi.org/10.1212/wnl.0000000000005550}
}
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