LONDON ¿ Celltech plc, of Slough, which specializes in humanized antibodies, said it expects to file its first U.S. new drug application during the third quarter of 1999 for CMA 676, a treatment for acute myeloid leukemia (AML), and, if approved, will launch the product in 2000.

The company reported the latest results on the compound, being developed in collaboration with American Home Products Corp., at last week¿s American Society for Clinical Oncology meeting.

In a multi-center U.S. pivotal study, there was an overall remission rate of 36 percent in 59 first-relapse patients treated, with complete clearance of clinically evident leukemic cells. More than 100 patients now have received CMA 676 in three trials, with remission rates ranging from 36 percent to 44 percent. The favorable safety profile, compared to chemotherapy, was maintained in the latest study.

A study in first-relapse pediatric patients has now begun, and Celltech plans to conduct further studies in induction of first remission in AML and other types of leukemia. CMA 676 consists of a human antibody that targets leukemic cells, linked to the cytotoxic drug calicheamicin.

Celltech also reported progress with its human anti-TNF alpha antibody CDP 571, which previously failed in a Phase III study in sepsis conducted by Bayer. Celltech now is developing the compound as a treatment for Crohn¿s disease, and is awaiting the results of potentially pivotal Phase II trials in 240 patients in centers in the U.S., Canada and the U.K.

In the first study, the drug is being evaluated in 170 patients with active disease, while the second study is assessing the ability of the drug to maintain remission in 70 patients who are on high doses of steroids. The steroid dose was progressively reduced during the four-month study period, which is now complete. Celltech is looking for a partner for the compound and expects to file a U.S. biologics license application in 2000.

This update accompanied financial results for the six months that ended March 31, 1999, which showed the company¿s income from antibody technology licenses nearly doubled at #5.3 million (US$8.5 million), up from #2.7 million for the same period in 1998. There are seven antibody products on the market that rely on Celltech¿s Boss patent, and licensing income is expected to continue to grow. However, the loss for the period was significantly higher at #5.7 million, against #2.9 million. That was a result of higher R&D costs of #11.5 million, up from #9.4 million, due to the CDP 571 studies.

The company had #34.3 million in cash on March 31. n