Avant soars as cancer vaccine doubles survival

Shares of Avant Immunotherapeutics Inc. surged today, after the Needham vaccine developer and partner Pfizer Inc. released mid-stage data showing their vaccine doubled overall survival time and delayed disease progression in certain brain cancer patients.

The companies presented data from two Phase 2 studies at the American Society of Clinical Oncology's annual meeting in Chicago. CDX-110 is an experimental vaccine targeting a growth factor specific to tumors in patients with glioblastoma multiforme (GBM), the most common and agressive form of brain cancer.

There are an estimated 10,000 new cases of GBM annually in the United States, including the case of US Senator Edward M. Kennedy. An aggressive tumor with a traditionally very poor survival prognosis, current treatment options include surgical tumor removal, radiation and chemotherapy.

(Photo at right is of Una S. Ryan, president and chief executive of Avant.)

In a study of 23 patients with GBM, patients receiving the vaccine lived an average of 33.1 months, compared with 14.3 months for patients receiving standard therapy. The time it took for tumors to recur also more than doubled to 16.6 months for patients receiving the vaccine, from the historical 6.4 months.

The companies said CDX-110 was generally well-tolerated in the ACT II study, with side effects mainly reported as injection site reactions. Avant is starting a mid-to-late-stage clinical trial called ACT III, to evaluate the vaccine in 90 patients at over 20 cancer centers across North America and confirm the latest results. The Phase 3 portion of the trial won't open until data is available from Phase 2b and pending further discussions with the FDA.

Another study of 21 newly-diagnosed GBM patients who had had surgical tumor removal and radiation therapy before starting the vaccine lived an average of 26 months compared with 15.2 months in patients on standard therapy alone. No significant adverse events were seen in this ACTIVATE study.

In midday trading on the Nasdaq Stock Market, Avant shares rose $4.21, or 30 percent, to $18.22 on sharply higher volume, and earlier reached a new 52-week high of $19.79. Pfizer shares slipped 19 cents to $19.17 in trading on the New York Stock Exchange. (AP)