Johnson & Johnson (NYSE:JNJ) takes a critical step toward approval of a new diabetes drug Thursday but it must first answer questions about the medicine’s safety. In documents prepared for a panel of US government advisers released Tuesday staff reviewers for the Food and Drug Administration said J&J’s experimental therapy Invokana appears to work but also may have some safety risks that need to be discussed before any approval is granted for the product. Side effects for the drug also known as canagliflozin are being examined by government officials. FDA reviewers appear to be most concerned about cardiovascular risk ...