* Says FDA seeks more data to evaluate vaccine's safety
* Says FDA willing to discuss restricted approval
* Shares fall as much as 38 pct premarket
By Zeba Siddiqui
Feb 25 U.S. health regulators denied approval
for Dynavax Technologies Inc's adult hepatitis B
vaccine and sought additional data to evaluate its safety,
delaying the market entry of a faster-acting and less frequently
needed vaccine for the liver-attacking infection.
The rejection of Heplisav - Dynavax's most advanced clinical
candidate - sent the company's shares down as much as 38 percent
to $1.84 before the bell on Monday.
The U.S. Food and Drug Administration indicated in a
complete response letter to Dynavax that it was willing to
discuss a more restricted use of the vaccine, the company said
in a statement.
Dynavax pitched Heplisav for use in patients between 18 and
70 years of age, and the vaccine showed promising efficacy in
clinical studies after the administration of just two doses.
GlaxoSmithKline Plc's Engerix B - the most widely
used hepatitis vaccine in the world - requires three or four
doses in adults.
"There are a few possibilities - one is for adults 40 to 70
years of age, because in these older adults, the immune system
is more compromised, so they benefit more from Heplisav. The
current standard-of-care does not work very well," William Blair
& Co analyst Katherine Xu said.
The company could also explore seeking approval for at-risk
hepatitis B populations such as patients with HIV, HCV, diabetes
and those on dialysis, Xu added.
Dynavax filed with European regulators last July for
approval of Heplisav in adults with chronic kidney disease,
which is very often associated with hepatitis B.
An estimated 3.5 million to 5.3 million people are living
with viral hepatitis in the United States, and vaccination is
crucial as it prevents progression of the infection, which is
the leading cause of liver cancer.
Dynavax estimates the global market for adult hepatitis B
vaccines at about $700 million annually.
The FDA noted that the novel adjuvants in Heplisav may cause
rare autoimmune events, Dynavax added.
Adjuvants are added to vaccines to improve their ability to
trigger an immune response, but they carry the risk of causing
several potentially fatal adverse reactions.
"Furthermore, the FDA requested additional data ...
clarifying information on the manufacturing controls and
facilities related to the assurance of the quality of the
commercial product," Dynavax said on Monday.
The company said it expects to meet with the FDA within six
weeks to discuss the steps required for Heplisav's approval.
The FDA echoed the concerns expressed in November by an
advisory committee that recommended against Heplisav's approval
and asked for data from a more diverse study population. The
advisors, however, voted unanimously to support the vaccine's
The Berkeley, California-based company's stock, which
touched a high of $5.00 before the FDA committee's
recommendation in November, has lost about 36 percent of its
value since then.
The FDA's rejection of the vaccine also brings into question
the future of Dynavax, which has no drugs on the market. The
company has been generating revenue so far through its research
and development alliances.
It has a bunch of clinical candidates under tests in
collaboration with British drug giants Glaxo and AstraZeneca Plc
, including potential treatments for asthma and
anti-inflammatory disorders such as rheumatoid arthritis and
Dynavax reported a loss of about $18 million and revenue of
about $3 million in the July-September period.