Investors are very eager to buy into biotechs and pharmaceuticals that are involved in developing weight-loss medications. This is why Viking Therapeutics (VKTX 7.92%), which has such a drug in its pipeline, has been a popular stock lately.

Over the past few trading days, Viking has made many investors richer; according to data compiled by S&P Global Market Intelligence, as of early Friday morning, it was up nearly 18% week-to-date. Some encouraging clinical results for the drug helped power the stock higher, as did analyst price target increases.

Obesity drug tests well, again

On Tuesday, Viking provided details of a phase 1 study of that weight-loss drug, currently tagged VK2735. The biotech reported that patients in the study who received tablets of the drug achieved noticeable weight loss after 28 days. The medication was also deemed safe and well tolerated; side effects were mild to moderate. The company aims to advance the drug to a phase 2 trial.

Viking is also putting VK2735 through its paces as an injectable treatment. It has also demonstrated weight-loss properties.

Several analysts tracking the company's stock wasted little time getting more bullish on its prospects. Pundits from Oppenheimer, BTIG, and Stifel all upped their fair-value estimations. Of the three, the most optimistic was Oppenheimer, which set a new price target of $138.

A bright future for VK2735, one analyst believes

In raising his level (from the previous $116), Oppenheimer's Jay Olson maintained his outperform (read: buy) recommendation on the stock. The analyst was particularly cheered by the fact that Viking has a solid opportunity to test different dosing and administration models.