The vaccine shrank tumors that were directly
injected with the drug and tumors around the body that were not
injected, according to the data.
The drug, talimogene laherparepvec, also known as T-vec, is an
engineered virus designed to replicate inside the injected tumor,
killing cancer cells there, as well as prime the immune system to
attack other cancer cells around body.
Dr. Robert Andtbacka, one of the study's lead investigators, in a
telephone interview, called the results "very encouraging."
Amgen last year released initial data from the 295-patient Phase III
study showing that T-vec succeeded in demonstrating a significant
tumor response that lasted at least six months. The latest data
analyzed 4,000 tumor lesions to study the response to the drug in
injected versus non-injected tumors.
Of the directly injected tumors, 64 percent shrank by at least half,
and 47 percent of those had a complete response, meaning the lesion
had disappeared, researchers said.
Of the uninjected lesions in the skin or lymph nodes, known as
non-visceral tumor lesions, 34 percent shrank by at least half with
a complete response seen in 21 percent of those.
"We also want to see responses in distant lesions that are not
injected such as in the liver, in the lung and other places,"
Of those so-called visceral tumors on solid organs, 15 percent
shrank by at least 50 percent, said Andtbacka, who presented the
data at the Society of Surgical Oncology Cancer Symposium in
"This indicates to us that we have activation of the immune system
to fight these tumors at a distant site," Andtbacka said.
"This is a new generation of oncolytic immunotherapy where you're
seeing very robust responses in injected lesions but also robust
responses in non-injected lesions. This bodes well for the future
for this product," added Andtbacka, an associate professor in the
division of surgical oncology at the University of Utah School of
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Amgen said it expects to have further data in the first half of
this year showing whether T-vec ultimately helped patients in the
study to live longer. The company has not yet said when it will
apply for approval of the medicine.
Andtbacka said he expects the future of the drug will involve its
use in combination with other types of cancer immunotherapies,
especially in treating patients with non injectable visceral tumors.
Amgen is already testing T-vec in combination with Bristol-Myers
Squibb's melanoma drug Yervoy and has agreed to study T-vec in
combination with Merck & Co's experimental immunotherapy from a
highly promising class called PD-1 inhibitors.
Melanoma is the most aggressive form of skin cancer. About 132,000
melanoma cases occur globally each year, according to World Health
"We are extremely excited about the data and the potential for
combinations with other treatments," said David Chang, Amgen's head
of global oncology development.
(Reporting by Bill Berkrot; editing by
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