Updated from 2:22 p.m. EDT

Shares of

Introgen Therapeutics

(INGN) - Get Report

were among the best-performing health and pharmaceutical stocks Thursday, rising 15.3% after the company's cancer drug showed promising results in phase II trials.

The company's Advexin drug (which is used to treat breast cancer), when used in with neoadjuvant chemotherapy, reduced tumor size by an average of 80% in 12 patients with locally advanced breast cancer who subsequently underwent surgery to remove residual tumors.

"These very promising data suggest that advexin may be combined with neoadjuvant chemotherapy to further reduce tumor size and improve patient outcomes by facilitating complete surgical tumor removal," the company said. Shares traded up $1.17 to $8.82.

Dynavax Technologies

(DVAX) - Get Report

rose 9.6% after the company said its vaccine to treat hepatitis B showed "statistically significant superiority" in protective antibody response after two vaccinations compared with

GlaxoSmithKline's

(GSK) - Get Report

Engerix-B vaccine. The vaccine was used in an older adult population that is typically more difficult to immunize with conventional vaccines. Based on the results, Dynavax now plans to pursue a broad phase III trial using multiple age groups. The trial is expected to begin in mid-2005. Shares traded up 70 cents to $8.

Shares of

Nastech Pharmaceutical

( NSTK) fell 8.4% after the company sold 4.25 million shares of stock for $13.50 apiece, yielding proceeds -- before underwriting fees -- of $57.4 million. The price represents a 4% discount to Wednesday's closing price of $14.07. Shares traded down $1.18 to $12.89.

Symmetry Medical

(SMA)

rose 24% on its first day of trading as a public company. The medical-device maker priced 8 million shares at $15 apiece, raising $120 million. The pricing came in at the high end of its expected range of $13 to $15 a share. Banc of America Securities and Credit Suisse First Boston led the underwriting syndicate. Shares traded up $3.60 to $18.60.

Other health care volume movers included

Pfizer

(PFE) - Get Report

, down 13 cents to $27.37;

Biomira

(BIOM)

, up 14 cents to $2.68;

Merck

(MRK) - Get Report

, up 4 cents to $28.73;

Occulogix

( RHEOV), unchanged $12; and

Amgen

(AMGN) - Get Report

, up $1.26 to $64.33.