* Fostamatinib relieves rheumatoid arthritis symptoms
* New pill fails to impact joint damage measured by X-ray
* Side effects include hypertension and diarrhoea
* Rigel shares slump 33 pct, AstraZeneca little changed
(Updates with latest Rigel share price, further analyst
By Ben Hirschler
LONDON, April 5 AstraZeneca's
experimental rheumatoid arthritis pill fostamatinib met only one
of two goals in a late-stage clinical trial, leaving the future
of one of the group's few advanced pipeline products uncertain.
Shares in its smaller U.S. partner Rigel Pharmaceuticals
slumped 33 percent in early Nasdaq trade on the news.
Fostamatinib is a potential competitor to injectable drugs
like AbbVie's Humira and a new pill from Pfizer
called Xeljanz in a $20 billion-plus market. Disappointing
results from earlier tests, however, mean investor hopes for the
medicine are low.
The latest findings will do little to restore confidence,
especially as increased blood pressure and diarrhoea were again
noted among patients taking the AstraZeneca product.
"Our misgiving is that fostamatinib appears to be inferior
to Humira on efficacy and now the adverse events seem to pitch
it below Pfizer's (Xeljanz), so it is hard to see where the
product will fit," said Panmure Gordon analyst Savvas Neophytou.
Results of another AstraZeneca-funded study in December
found fostamatinib was inferior to Humira in controlling
In the latest trial, AstraZeneca's new drug achieved a
statistically significant improvement at 24 weeks, compared to
placebo, in a test assessing signs and symptoms of the disease -
the so-called ACR20 response rate.
But it failed to show an improvement in an X-ray test
measuring the progression of joint damage, according to results
from the OSKIRA-1 Phase III study released by the company on
Side effects seen among patients taking the drug were
similar to those experienced in earlier studies, including
hypertension, diarrhoea, nausea, headache and common cold.
Hypertension is a particular concern, since raised blood
pressure could be a serious obstacle to approval.
ISI Group analyst Mark Schoenebaum said even if fostamatinib
was approved in 2014, as AstraZeneca and Rigel hope, its use
would be secondary to Xeljanz and other oral arthritis drugs
that are expected to be approved over the next few years.
Fostamatinib's ACR20 scores of 44-49 percent were lower than
the 52-62 percent seen with Xeljanz in Phase III studies, he
AstraZeneca licensed fostamatinib in 2010 from Rigel and the
South San Francisco, California-based company's fortunes are
closely tied to the medicine, since it does not yet have any
drugs on the market.
Given the doubts surrounding the product, forecasts among
AstraZeneca analysts for fostamatinib sales are low, averaging
just $171 million in 2016, according to Thomson Reuters data.
Humira, by contrast, has annual worldwide sales of more than
Briggs Morrison, head of global medicines development at
Britain's second-biggest drugmaker, said the latest study
findings showed the new pill did have an effect in rheumatoid
But AstraZeneca is being cautious about talking up
fostamatinib's prospects and its researchers want to see more
results before deciding their strategy for the drug.
"We will await the results of the remaining Phase III
studies, OSKIRA-2 and OSKIRA-3, to further evaluate and
characterise the profile of fostamatinib as a potential
treatment for rheumatoid arthritis," Morrison said.
The OSKIRA-2 and OSKIRA-3 results are expected later in the
second quarter of 2013.
With last year's loss of exclusivity on schizophrenia drug
Seroquel, and Nexium for stomach acid and cholesterol fighter
Crestor set for U.S. patent expiries in 2014 and 2016,
AstraZeneca faces one of the industry's steepest "cliffs" of
Worryingly, it has few new drugs in late-stage development
to replace them, which is something that new CEO Pascal Soriot
aims to address through a radical shake-up of the group's
Shares in AstraZeneca were little changed in London.
(Editing by Helen Massy-Beresford and Clelia Oziel)