By Debbie Strickland

In a deal conservatively estimated at $35 million, Bayer AG has gained access to Genzyme Corp.'s library of more than 1 million small molecules, along with rights to develop any hits that emerge from churning the compounds through the pharmaceutical company's battery of high-throughput screens.

Bayer did not disclose disease targets.

The $35 million figure is based on just one or two hits, said Genzyme spokeswoman Cheryl Greenhouse. If Bayer develops more compounds, the milestone payments could jump.

Genzyme will receive up-front and service fees, plus milestone payments as selected compounds proceed through clinical trials.

The Leverkusen, Germany-based pharmaceutical company joins five other partners in screening Genzyme's library, which has been assembled over the course of three years as part of a small-molecule discovery program. The program also has produced 30 biological drug-discovery assays plus lead compounds in the core therapeutic areas of cancer, infectious disease and autoimmune and inflammatory diseases.

At the other end of the pipeline, Genzyme this week submitted a new drug application to the FDA and a marketing authorization application in Europe for Thyrogen, a recombinant human thyroid stimulating hormone for use in diagnosing thyroid cancer recurrence.

Approval is likely in 1998, with sales estimated at $15 million in 1999 and $21 million in 2000, according to analyst Peter Drake ,of Vector Securities International Inc., in Deerfield, Ill.

"We believe that Thyrogen represents a significant step forward in the management of patients with thyroid cancer who undergo the primary treatment — surgical removal of the thyroid gland," Drake stated in a report on the regulatory submissions.

Thyrogen boosts bloodstream levels of thyroid stimulating hormone (TSH). Patients who have had thyroid cancer must increase their bloodstream levels of TSH by several fold prior to annual or biannual screens for cancer recurrence.

The conventional method for elevating TSH is to take patients off synthetic supplements three weeks prior to testing. That method works, but patients develop symptoms of hypothyroidism, including fatigue, weight gain, constipation, mental dullness, lethargy and depression.

With Thyrogen, patients continue taking hormone supplements, thus avoiding these symptoms.

Data from a recent 220-patient Phase III trial showed the hormone produced scans that were equivalent to scans produced by the hormone withdrawal method in more than 90 percent of patients — a statistically significant result. (See BioWorld Today, June 12, 1997, p. 1.)

The company currently has one other drug under FDA review, RenaGel, under development through a 50-50 joint venture with GelTex Pharmaceuticals Inc., of Waltham, Mass. RenaGel is a non-absorbed phosphate binder for the control of elevated phosphate levels associated with chronic kidney failure.

Genzyme shares (NASDAQ:GENZ) closed Thursday at $25.875, down $1.125. *