CSL Ltd (ASX: CSL) shares are ending the week in the red.
At the time of writing, the biotechnology giant's shares are down almost 2% to $281.78.
Why are CSL shares falling?
With no news out of the company, it isn't clear why its shares are under pressure today.
But given how some analysts believe that weight loss drugs could have a negative impact on the company's sales, it's possible that news of a new wonder drug could be weighing on sentiment.
Earlier this week, Viking Therapeutics (NASDAQ: VKTX) shares rocketed over 100% after announcing positive top-line results from its phase 2 clinical trial of VK2735.
It is a dual agonist of the glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) receptors that is in development for the potential treatment of various metabolic disorders such as obesity.
Viking revealed that the phase 2 trial successfully achieved its primary endpoint and all secondary endpoints. Patients receiving VK2735 demonstrated statistically significant reductions in body weight compared with placebo.
Importantly, the study showed VK2735 to be safe and well tolerated with the majority of treatment emergent adverse events (TEAEs) being categorised as mild or moderate.
Is this a threat to CSL?
Opinion remains divided on whether GLP-1s are a threat to CSL and its shares. A number of analysts believe they could be due to the possible kidney benefits resulting from their use. However, CSL doesn't believe this will be the case.
As we covered here late last year, the company's CEO, Paul McKenzie, commented:
There's been a lot of talk about GLP-1s […] To give you the punchline, based on the high-level results, we do not see GLP-1s as having a material impact on the business.
This sentiment was echoed by CSL Vifor general manager, Hervé Gisserot. He said:
In our view, as already stated by Paul, the renal disease market won't be disrupted by GLP-1.