Science - 06.12.2019

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FDA approves sickle cell drug
and Drug Administration (FDA) on
25 November approved a novel therapy
for sickle cell disease, an often fatal
blood disorder that afflicts about 100,
Americans. The drug, developed by Global

Blood Therapeutics based in South San
Francisco, California, is the first to target
the disease’s root cause—a mutant form
of the protein hemoglobin, which carries
oxygen inside red blood cells. Critics of
the drug complain that in clinical trials it
improved people’s blood test results but
not symptoms, such as pain caused when

sickled cells block small blood vessels. FDA
may approve drugs for serious conditions
based on improvements in “surrogate”
endpoints such as blood tests if other treat-
ments are lacking. The sickle cell drug will
cost about $125,000 annually; the firm said
it will explore how to provide the treat-
ment affordably in developing countries.



Edited by Jeffrey Brainard

Record high
temperatures across
Europe this summer
sent people wading in
fountains in Paris.


Older climate models pass temperature test


lder climate models, even those created half a century
ago, faithfully predict recorded increases in tempera-
ture, a study has found—suggesting scientists can trust
model predictions of future warming caused by rising
levels of greenhouse gases. Critics of climate science
often claim such models are flawed. But the new analy-
sis determined that the predictions of 10 out of 17 past climate
models released between 1970 and 2001 tracked with mea-
surements of global temperatures. And four of the inaccurate
models improved when scientists accounted for unanticipated
changes in the amount of greenhouse gases humans generated,

they report in the 4 December issue of Geophysical Research
Letters. Difficult-to-predict influences such as new regulations
can skew emissions and throw off a model’s temperature pre-
dictions, explains the paper’s lead author, Zeke Hausfather of
the University of California, Berkeley. But the overall accuracy
of even older models, simpler than those used today, confirms
that scientists’ understanding of the physics behind greenhouse
warming is sound, he adds. The findings come as officials from
around the world meet this week in Madrid for the United
Nations’s annual conference on climate change, with a focus on
implementing pledges to reduce greenhouse gases.

1174 6 DECEMBER 2019 • VOL 366 ISSUE 6470
Published by AAAS

on December 12, 2019^

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