Health stocks fell in line with the broader downtrending markets Monday, with a few stocks moving on data presented at the American Society of Clinical Oncology annual meeting over the weekend.

ImClone

(IMCL)

shares dropped $2.64, or 6%, to $40.94 on the first regular trading day since data were released from the FLEX and CRYSTAL studies. For more on the data released at ASCO, check out

TheStreet.com's recent coverage of ImClone

.

Avant Immunotherapeutics

( AVAN) and

Pfizer

(PFE) - Get Report

announced updated midstage-study data on a vaccine for cancer patients with brain tumors. The results sent Avant shares up $3.97, or 28%, to $17.98 Monday. Pfizer's shares were unaffected, falling 18 cents or 0.9% to $19.18.

Meanwhile,

Genentech's

( DNA) shares added $3.08, or 4.4%, to $73.95.

Data from the late-stage AVADO trial

, presented at ASCO, show that Avastin in combination with chemotherapy slowed cancer progression patients with metastatic breast cancer, supporting results of an earlier study that helped the drug gain approval in the breast cancer indication.

Back to the falling side,

Medarex

( MEDX) gave up ground after presenting data on its ipilimumab, which it's developing with

Bristol-Myers Squibb

(BMY) - Get Report

. Jeffries & Co. Eun Yang maintained her buy rating for the stock, while BMO Capital Markets analyst Jason Zhang, who has a market perform rating on the stock, questioned the validity of the company's claims regarding the effectiveness and survival benefits. Shares were down 63 cents, or 7.2%, at $8.08.

ImClone, Genentech and Medarex are components of the Nasdaq biotechnology index, which was down 1% at 809.35.

Away from ASCO,

Acorda

(ACOR) - Get Report

said Monday in a second late-stage trial its multiple sclerosis drug fampridine met the study's primary endpoint by

improving patients' walking ability

. Its shares were up $6.74, or 31%, at $28.30.

Also, the Food and Drug Administration approved

Abiomed's

(ABMD) - Get Report

Impella 2.5 cardiac assist device, which helps maintain blood flow in heart-failure patients during and after surgery. Shares added $2.32, or 15.7% to $17.10.