LONDON (Reuters) -
A new kind of antibody drug that makes
the body's own “killer” cells fight tumors has produced
promising early-stage results in patients with a deadly form of
blood cancer, researchers said on Thursday.

All seven patients with previously incurable non-Hodgkin's
lymphoma (NHL) who were given the highest dose of Micromet
Inc's experimental drug blinatumomab showed either complete or
partial responses.

The results, which were published in the journal Science,
are a boost for the concept of harnessing the power of the
body's cytotoxic, or cell-destroying, T-cells against tumors.

Until now, scientists have struggled to find a way of
triggering a T-cell attack. But blinatumomab works by binding
them to cancer cells, allowing the T-cells to more effectively
kill the tumor.

Importantly, it does so without setting off uncontrolled
T-cell activity. Two years ago six men were left seriously ill
when a clinical trial of another experimental drug made by
TeGenero went badly wrong.

“It's a very different kind of response,” Patrick Baeuerle,
Micromet's chief scientific officer, told Reuters. “It does
activate the T-cells but it only activates those in contact
with a tumor cell, so it is very conditional.”

If all goes well, German-U.S. firm Micromet hopes next year
to conduct a pivotal clinical trial necessary to win regulatory
approval.

The drug, for which AstraZeneca has marketing rights in
North America, is also in mid-stage Phase II clinical tests
against acute lymphocytic leukemia.

In the Phase I trial reported for NHL, 38 patients were
given varying doses of the drug, with 11 of those receiving
higher dosages showing major responses and tumor regression,
despite being given no other supporting chemotherapy.

There were a number of side effects with the product, which
targets a protein called CD19, but most occurred in the first
week of treatment and usually normalized.

Significantly, the amount of drug needed was much lower
than for existing antibody treatments such as Roche and
Genentech's Rituxan/MabThera.

“With these low doses, cost of goods should not be much of
an issue,” said Baeuerle.

(Editing by Paul Bolding)