In 2016 AbbVie paid about $5.8 billion upfront for Stemcentrx and its lead drug Rova-T. By the end of 2019 AbbVie had written off the entire $6.1 billion of acquired in-process research and development, and ended the Rova-T program.
This page sets out what AbbVie’s own filings say, what the key scientific papers say, and the questions a citation-chain audit would put to the evidence. Every figure below was read from the cited source. It does not claim that an audit would have prevented the loss.
| Apr 25, 2016 | AbbVie signs the merger agreement. Upfront consideration of approximately $5.8 billion: 62.5 million AbbVie shares (about $3.8 billion, at a fixed value of $60.664 per share as stated in the filing) and about $2.0 billion in cash. | AbbVie 8-K, Apr 29 2016 |
| Jun 1, 2016 | AbbVie completes the acquisition. | AbbVie 8-K, Jun 1 2016 |
| Dec 2018 | AbbVie stops enrollment in TAHOE, a Phase 3 trial of Rova-T as a second-line therapy for advanced small cell lung cancer. An Independent Data Monitoring Committee recommended stopping because of shorter overall survival in the Rova-T arm than in the topotecan control arm. | AbbVie 10-K, fiscal 2018 |
| Jan 4, 2019 | AbbVie reports that the estimated net impact of the impairment and the related adjustment to contingent consideration is approximately $4 billion, and that it will monitor the remaining $1 billion of intangible assets. | AbbVie 8-K, Jan 4 2019 |
| Fiscal 2018 | Pre-tax impairment of $5.1 billion on the acquired in-process research and development, whose carrying value of $6.1 billion was reduced to a fair value of $1.0 billion. Net of the contingent-consideration adjustment, the Stemcentrx-related charge was $4.1 billion after tax. | AbbVie 10-K, fiscal 2018 |
| Aug 2019 | AbbVie terminates MERU, a Phase 3 first-line maintenance trial, after no survival benefit at a pre-planned interim analysis versus placebo, and ends the Rova-T program. A further $1.0 billion impairment in 2019 covers the remaining acquired value. | AbbVie 10-K, fiscal 2019 |
The widely quoted “$4 billion” is AbbVie’s January 2019 estimate of the net impact, after an adjustment to contingent consideration. The filed totals are the figures above. AbbVie also reduced its Stemcentrx contingent consideration liability by $428 million in the fourth quarter of 2018 and by $91 million in 2019 (10-Ks).
Rova-T targets DLL3, a protein AbbVie’s filing describes as cancer-stem-cell associated. The idea that a small group of “stem-like” cells drives a cancer was developed first in blood cancer. These three papers are the ones set out here as the evidence behind that idea and the DLL3 drug; AbbVie’s own deal rationale is not in the filings read for this page.
| 1997 | Leukemia-initiating cells in acute myeloid leukemia were shown to have the properties of stem cells, and the leukemia was described as organized as a hierarchy. | Bonnet & Dick, Nature Medicine 1997, PMID 9212098 |
| 2009 | In small cell lung cancer xenografts, a CD133-high subpopulation had markedly enhanced tumorigenicity. The authors wrote that their findings suggest a broad range of small cell lung cancer cells has tumorigenic capacity rather than a small discrete population. | Jiang et al., Cancer Research 2009, PMID 19176379 |
| 2015 | The paper that described the DLL3-targeted antibody-drug conjugate, called first-in-class in its abstract. In patient-derived mouse models, serial transplantation with limiting dilutions of cells provided functional evidence that lack of recurrence after treatment resulted from targeting DLL3-expressing tumor-initiating cells. | Saunders et al., Science Translational Medicine 2015, PMID 26311731 |
The first two questions could be asked from the literature at signing in April 2016. The last two draw on AbbVie’s later filings and show how the evidence developed. None is a finding that the deal was wrong. The method behind them, tracing each load-bearing claim to its primary source and tagging each link supported, partial, contradicted or missing, is described on the main page.
Hindsight is cheap, and several outcomes here (a monitoring committee’s survival finding, a failed interim analysis) were not knowable at signing. What an audit can do is lay out, before the money moves, which links in the chain are strong and which rest on a single type of evidence.