By Karen Bernstein

As profit margins on drug sales are squeezed by changes in the pharmaceutical markets, it's likely there will be more deals between companies pooling both sales forces and related products to gain marketing clout.

One model for the future could be last week's agreement between MedImmune Inc. and American Cyanamid Co. The deal covers three products for respiratory syncytial virus (RSV) and one broad anti-infective. Each company contributes two products.

MEDI is contributing Respivir, a polyclonal antibody awaiting FDA approval for prophylactic use in children at high risk of RSV; and a second-generation monoclonal antibody in preclinical development to prevent and treat RSV.

Cyanamid, together with its Lederle Laboratories and Lederle Praxis Biologicals divisions, is contributing Zosyn, a broad-spectrum anti-infective for hospital use for which marketing approval is expected later this year; and a vaccine for RSV that is in Phase I/II trials in toddlers. Zosyn is a combination of piperacillin, a semisynthetic penicillin, and tazobactam, a betalactamase inhibitor.

1,000 sales reps

MEDI will sell the products to hospitals, while Lederle will sell to hospitals and pediatricians through its 1,000-person pediatric sales force. The companies will co-promote Respivir in the U.S. and co-develop and co-promote MEDI's MAb. MEDI would co-promote Zosyn and would have the