* Hybridon Inc., of Cambridge, Mass., began treatment in a Phase I dose-escalation trial of its second-generation antisense product, GEM 231, in patients with refractory solid tumors. GEM 231 is an 18-mer RNA/DNA hybrid antisense oligonucleotide, intended to inhibit expression of the R1-a subunit of protein kinase A. The trial is expected to enroll up to 25 patients.

* Cephalon Inc., of West Chester, Pa., said its subsidiary in the U.K., Cephalon U.K. Ltd., entered into a 10-year agreement with Laboratoire Aguettant SA, of Lyon, France, to promote and market Apokinon (apomorphine hydrochloride) in France for Parkinson's disease. The drug is injected subcutaneously with a metered-dose pen device designed and developed in France by Aguettant. It is used in treating levadopa therapy fluctuations common in late-stage sufferers of Parkinson's disease.

* Penederm Inc., of Foster City, Calif., entered an agreement with Alpharma Inc., of Fort Lee, N.J., to market Alpharma's permethrin cream 5 percent for the treatment of scabies infection. Penederm will market the drug in the U.S. under its Acticin brand name. Alpharma will manufacture and supply the product to Penederm, which will pay Alpharma milestones and royalties based on product sales and profits.

* IGEN International Inc., of Gaithersburg, Md., completed two milestones in a high-throughput screening agreement with Agouron Pharmaceuticals Inc., of San Diego. The companies completed optimization and validation of IGEN's assay and the first segment of compound analysis.