Teva Pharmaceutical Industries ( TEVA), the maker of the popular multiple sclerosis treatment Copaxone, says it has stopped work on a pill version of the drug. Teva received discouraging results earlier this month from two midstage clinical trials, prompting the company and its partner, H. Lundbeck of Denmark, to halt development of a coated pill for MS. "Nevertheless, Teva is considering future development of Copaxone in various noninjectable formulations and will make its decision in the context of its entire MS portfolio," the Israeli company said in a Monday filing with the Securities and Exchange Commission. An MS pill is a major research goal, and many companies -- even those that don't make MS drugs -- are looking for a solution. Teva had been conducting clinical trials on oral Copaxone for six years. Results from trials in 2000 and 2002 weren't statistically significant. In late 2004, Teva and Lundbeck tried again, but the results weren't good enough. Teva is involved in two other efforts to find an MS pill. Since 2004, it has been working with Active Biotech of Sweden on laquinimod. Results of a midstage clinical trial, held in several European countries, are due this year. Teva also is discussing with the Food and Drug Administration the possibility of conducting U.S. clinical trials. Teva has rights to the compound in all but Nordic and Baltic countries. Additionally, Teva is indirectly involved in MS pill research thanks to its recent acquisition of Ivax, a former rival generic drug company. Ivax has had a deal with Switzerland's Serono ( SRA) for developing an MS pill. "Ivax has a passive financial interest in such agreement, but does not have any active involvement in the development of this product," says the Teva SEC filing. The Ivax-Serono product, called Mylinax, is a pill version of injectable cladribine, which treats a form of leukemia. "Previous clinical trials had demonstrated the positive effect of injectable cladribine in patients with multiple sclerosis as well as a dramatic reduction in new lesion development,' Teva says. Last year, Serono commenced a two-year clinical trial of Mylinax involving 1200 MS patients. Although Teva is the world's biggest maker of generic drugs, the brand-name Copaxone provided $1.18 billion of last year's revenue, or 22% of its total, and a bigger percentage of its profit. Copaxone is sold in 44 countries and has been available in the U.S. since 1997. Shares of Teva were off 18 cents to $42.35 Tuesday.