By Mark Zipkin, Staff Writer
Having helped expose the reproducibility
crisis about five years ago, Amgen Inc. is staying at the forefront of the
issue with its support of F1000Research, an open-science platform to let
researchers check each other’s data. BUt as the field wrestles with causes and
solutions, some academics are starting to bristle at the intrusion.
The issue was sparked by a pair of papers in
2011 and 2012 from Bayer AG and Amgen, respectively, that showed each company
could only reproduce a small percentage of published data when the experiments
were tried in-house.
Although many companies routinely rerun
published experiments to verify them, they rarely go
the distance of publishing their findings.
Alexander Kamb, SVP of discovery research at
Amgen, told BioCentury there has long been a “culture of publication” at the
company that has included publishing negative data, but the environment in the
scientific community is changing to make that rarer.
“The nature of the process is more challenging
and tends to favor new findings as opposed to reconsideration of something,”
said Kamb. He added that in current climate, “more prosaic, disconfirming
results aren’t so easily published.”
Now. Amgen has put its weight behind the
efforts of life science publisher Faculty of 1000(F1000) to address the problem
with the launch of the Preclinical Reproducibility and Robustness channel on
the publisher’s F1000Research
platform.
On Feb. 4, to mark the channel’s launch, Kamb
published a joint editorial with Bruce Alberts, former editor in chief of Science and an F1000Research advisory board member, outlining the goal of the
channel as an effort “aimed at strengthening the self-correcting nature of
science through the widespread, rapid publication of the failures (as well as
the success) of attempts to reproduce published scientific findings.”
The same day, Amgen posted the channel’s first
three papers in which the biotech documented experimental details of internal
studies that refute published findings from four different groups, including
one paper from its own scientists.
Naming Names
The channel was the brainchild of Kamb and
Alberts. According to Michael Markie, associate publisher at F1000Research, the increasing unease in
the scientific community about the reproducibility crisis prompted the duo to
create an alternative publishing outlet to traditional journals, which
routinely prioritize the impact of a study over its rigor.
According to Markie, publishing in the F1000Research channel differs from
publishing in a journal in several key ways.
First is speed to publication: submissions are
posed after editorial checks - covering ethical standards, methodology and open
access to the data - are performed, but before any peer review.
In addition, publication does not hinge on the
potential impact on the field.
Reviewers are solicited once a prepublished
study is posted to the channel’s site, where readers can also post comments. F1000Research authors choose their
referees, although the publisher screens the choices to prevent conflicts of
interest.
Once three referees approve a paper, F1000Research indexes it widely on
search engines such as PubMed.
Markie said that although there’s still a
certain stigma attached to openly contesting published findings, the platform
is designed for transparency and dialogue.
The idea that the preclinical research
community could go beyond the stigma came from a dispute around results from
the Mouse ENCODE Consortium.
In 2014, two papers by the consortium’s
scientists published in Nature and
the Proceedings of the National Academy
of Sciences presented controversial findings on comparative gene regulation
data, claiming that the patterns of gene expression data tended to cluster more
by species than tissue. The studies contradicted common beliefs in the field.
“It was kind of known in the genomics world
that a certain study was quite difficult to believe. It was like the whispers
of the conference hall,” said Markie.
In 2015, two researchers from the University
of Chicago refuted the findings in the Genomics, Computational & Systems
Biology subject area of F1000Research. After the negative data were posted,
four referees — with names attached — approved it, although one approved it
with reservations.
According to Markie, the widespread attention
prompted a healthy discussion.
“What happened there was a big lively debate
with a lot of the key stakeholders in that area of science who all chipped in,
in a constructive way,” he said, adding that even the original authors
contributed to the conversation. “Everything was quite civil.
NEGATIVE FINDINGS
The studies Amgen posted on the new channel
address the roles of specific pathways in obesity, neurodegeneration and Alzheimer’s
disease (AD). All three are still awaiting peer review. The first challenged a
pair of 2012 publications concerning GPR21 in obesity.
A paper in Biochemical and Biophysical
Research Communications by Amgen researchers reported that GPR21-knockout mice
were resistant to diet-induced obesity, and one in The Journal of Clinical
Investigation from the University of California San Diego and Pfizer Inc.
showed GPR21 knockout improved insulin sensitivity.
But in Amgen’s F1000Research findings, new
GPR21-knockout mice were generated that did not replicate either of the earlier
studies. Instead, the paper suggested the metabolic phenotypes of the original
GPR21 knockout mice were due to unintentional changes in expression of a nearby
gene, RABGAP1, caused during generation of the knockouts.
Because mouse GPR21 is encoded within a
RABGAP1 intron, the F1000Research paper’s authors thought the neomycin cassette
insertion used to generate the original knockout mice might have altered
RABGAP1 expression. In the new knockout mice — which were generated via a
29-base pair deletion in GPR21 using transcription activator-like effector
nucleases (TALENs) — RABGAP1 expression was unaffected, and the mice showed no
improvements in glucose and insulin metabolism compared with wild-type
littermates.
The second paper contested a 2010 Nature
report from a group at Harvard Medical School that suggested USP14 slows the
degradation of proteasome substrates such as tau and TDP-43, which play an
important role in neurodegenerative diseases. Whereas the Harvard group’s
evidence showed a catalytically inactive form of USP14 decreased tau and TDP-43
levels in HEK293 cells compared with functional USP14 — supporting the idea
that functional USP14 prevents their degradation — the Amgen team found no
difference between the two. In addition, siRNA knockdown of USP14 by the Amgen
team did not affect endogenous tau expression in a different cell line.
The Amgen team indicated in its paper that
differences in the method, such as the expression vector used, could underlie
the discrepancy, and noted that follow-up studies by the Harvard group had
failed to show the USP14 effect occurred in vivo.
At least one company has been targeting USP14.
In 2013, Proteostasis Therapeutics Inc. received a grant from The Michael J.
Fox Foundation for Parkinson’s Research to develop a USP14 inhibitor to promote
clearance of α-synuclein to treat Parkinson’s disease (PD), aiming for the
clinic in 2015
In December 2013, Proteostasis announced a
partnership with Biogen Inc. to continue development, and in 2014 it received
milestone payments from Biogen. Biogen did not respond to requests for comment.
The third paper was the only one to receive a
response so far — which highlighted how some in the community are viewing the
initiative.
The study centered on results from a 2012
Science paper from an academic group headed by Gary Landreth at Case Western
Reserve University School of Medicine. Landreth’s study used a mouse model of
AD, and showed the RXR agonist Targretin bexarotene produced more than 50%
reduction of β-amyloid plaque area within 72 hours, reversed cognitive and
social behavior deficits, and improved neural circuit function. Landreth is a
professor of neurosciences and neurology, and director of the Alzheimer
Research Laboratory at Case Western.
The Amgen group treated wild-type
Sprague-Dawley rats with Targretin, but detected no significant change in
β-amyloid levels after three days or seven days. It did not perform behavioral
assays or examine neural circuit function.
In a response posted on F1000Research, Landreth argued that the reason for the difference
is that the Amgen researchers used “the wrong formulation.” In the 2012 study,
his group used the clinically approved formulation of Targretin, which is a
microcrystalline form of the drug. Amgen’s group used a soluble form of the
molecule, which Landreth stated would have a different PK profile that would
affect its activity.
He added in his response that the importance
of the formulation had been well documented in the literature and the FDA
filing, and was detailed in a response to four comments on his study published
in 2013 in Science. He also noted the use of different species in the Amgen
study.
“The Amgen scientists (and others) clearly did
not make an effort to understand and replicate the original study design,” he
wrote in his rebuttal on F1000Research.
Landreth concluded by stating a “logical flaw”
in the Amgen paper undermines its conclusion. “I think this study is emblematic
of the problems associated with reporting ‘failure to replicate’ findings in
studies that do not genuinely reproduce the published work,” he wrote.
According to Landreth, ReXceptor Inc. licensed
options from Case Western on the use of bexarotene in the treatment of AD.
ReXceptor did not respond to requests for comment.
At least one other company is developing an
RXR agonist: Io Therapeutics Inc. has IRX4204 in Phase I testing for AD and PD.
WHOSE CRISIS?
Since the problem was brought to light by
Amgen and Bayer, the academic community has responded with several initiatives
to address reproducibility (see “Reproducibility Initiatives”).
According to Kamb, to define what constitutes
“reproducible,” it’s important to think about what the data need to support.
“The key thing is that the clinical hypothesis
applies robustly in the maelstrom of the clinic,” he said. “So there is work
that might be defined ‘reproducible’ in a very narrow sense, but what we’re
trying to do here is find mechanisms and hypotheses that are robust enough to
really make it in the clinic.”
At the Global Biological Standards Institute
(GBSI)’s annual summit on Feb. 9, keynote speaker Judith Kimble said the two
papers kicking off the reproducibility crisis were “a bomb” for biomedical
researchers. However, she added, “The first question is, is it true? And I
think we don’t really know whether or not it’s true yet.”
Kimble is a professor of biochemistry at the
University of Wisconsin-Madison and an investigator at Howard Hughes Medical
Institute (HHMI).
Kimble questioned the accuracy of one of the
leading points of the summit: a GBSI-backed study published in a June 2015
Perspective in PLoS Biology which calculated the costs of irreproducible
clinical research at $28 billion.
“Trying to define what is reproducible and
what is not — what is a reproducible paper, what is a reproducible panel — is a
science in and of itself,” said Kimble. But regardless of the exact number, she
added, “There are clearly problems.”
During her talk, Kimble pointed to a number of
well-known causes of irreproducibility, covering inadequate training,
problematic stocks, lack of transparency and occasional fraud or misconduct.
But Kimble characterized these as symptoms, adding: “The elephant in the room
is hypercompetition.”
Hypercompetition, she said, has resulted from
ratcheting up the healthy competitive pressures of the field to “the point
where something starts to break.”
“I would say that the system is at that
point,” she added.
One culprit is the push from scientific
publishers, the job market and industry to see that results and publications
are clinically relevant, she said. Another driver is the increase in the number
of researchers while overall financial funding has decreased, with NIH funding
down 30% in constant dollars since 2003.
Although NIH received a budget increase of 3%,
bringing its total for FY16 to $31 billion, Kimble said it would require 5%
annual increases for the next five years just to get back to 2003 levels,
meaning it is unrealistic to expect the public sector alone to solve the
hypercompetition issue.
“This bomb that came in 2012 came from the
pharma/biotech industry,” said Kimble. She added: “The pharma/biotech industry
doesn’t do its own basic research anymore. It relies on research that’s paid
for by NIH, and yet it screams ‘bloody murder’ when things go wrong.”
F1000Research expects more companies besides
Amgen will get involved in the channel as it has actively solicited research
from industry, and Markie expects several pharmaceutical companies will jointly
publish a paper on the channel in the coming weeks. Still, he said, “We don’t
want it to turn into this ‘pharma can’t do it’ channel.”
“Obviously Amgen have taken the leadership
position here like they did with the Bayer article a few years ago,” said
Markie. But he hopes the channel will grow to see 50-100 publications annually,
from both industry scientists and academics, “when someone else apart from
Amgen has done it.”