Recently revealed trial results for Roche's experimental weight-management drug suggest Viking Therapeutics is on the right track.Weight-management treatments are all the rage lately. According to Morgan Stanley, combined sales of injections that curb appetites and promote weight loss could reach an estimated $105 billion by 2030.Viking Therapeutics (VKTX 3.25%) is still a clinical-stage drugmaker that's developing an anti-obesity candidate called VK2735 that appears competitive with a similar drug the U.S. ...