UK drug advisory body Commission on Human Medicines (CHM) has permitted Teva to reintroduce levothyroxine tablets in the United Kingdom market. CHM triggered the withdrawal of the product four years back by calling for the suspension of its marketing authorization on the grounds of evidence of lesser efficacy than the reference drug.
Teva’s levothyroxine tablets were supposed to be comparable to those marketed by another manufacturer. However, doctors reported reduced efficacy when switching patients from the reference product to Teva’s generic copy. When linked to manufacturing issues, CHM believed these reports were serious enough to warrant recommending the suspension of Teva’s levothyroxine. Now, almost 4 years after CHM made its original recommendation, Teva has come back with a formulation that addressestheconcerns of the CHM.
CHM described the re-formulation work undertaken by Teva as “extensive.” More significantly, data it started assessing in February suggest that the safety and efficacy of the drugs are acceptable. Teva presented data from clinical trials in volunteers demonstrating its re-formulated levothyroxine tablets trigger thyroid levels in the blood to increase to levels equivalent to those associated with the reference product. CHM also thinks modifications to the formulation and production process will ensure future batches of Teva’s drugs remain equivalent to the reference product throighout their shelf lives.
In reformulating the product, Teva has removed lactose from the tablets. The transformation means its new formulation can be taken by patients who are galactose intolerant — a product of the breakdown of lactose — or have some other conditions. Teva has also introduced new tablet strengths to its portfolio. In addition to 50 and 100 microgram tablets, Teva is manufacturing 12.5 and 25 microgram versions. CHM stated the broader range will help patients take the right dose without having to split tablets.