Data reported earlier Monday from Viking Therapeutics (NASDAQ:VKTX) on its weight loss medicine VK2735 indicates that Novo Nordisk (NVO) and Eli Lilly (NYSE:LLY), which currently dominate the obesity drug space, could face competition.

VK2735, which is being developed in both as an injectable and in pill form, is most closely related to Lilly's Zepbound (tirzepatide), given that both are dual GLP-1/GIP agonist. The oral form of VK2735 is in phase 1 while the injectable is in phase 2.

VK2735 grabbed attention on Monday with phase 1 data on the oral version, showing a patient's average loss of 8.2% of their body weight after 28 days. While weight loss results from Zepbound and Novo's Wegovy (semaglutide) are more favorable, both of those medicines are available as injectable only, and many patients are not comfortable taking medicines in that manner.

Lilly was also buoyed in August with results from a study showing that Zepbound greatly reduced the risk of heart failure. The same study showed a 15.7% weight loss over 52 weeks. Later the same month, Novo released results from a trial of Wegovy also demonstrating a heart failure risk reduction benefit.

On Monday, Viking also unveiled updated data on the injectable version of VK2735. Based on those blood plasma results, the company said the injectable version could be used for once monthly dosing. That would put it at an advantage over Zepbound and Weogvy, which are both dosed weekly.

Separately on Monday, Novo announced a partnership with Ascendis Pharma (ASND) to develop a once-monthly GLP-1 med.

Novo and Lilly are also working on oral weight loss drugs. In September, Novo released phase 2b data on monlunabant, a cannabinoid receptor 1 (CB1) inverse agonist, though the results appeared to disappoint investors. It also has another pill, amycretin. A phase 1 trial of amycretin released in September showed promising results.

Meanwhile, Eli Lilly has orforglipron, an oral GLP-1 in phase 3. At the Seeking Alpha Investing Summit in June, Louise Chen, managing director at Cantor Fitzgerald, said orforglipron is ahead in development compared to its competition.

Novo is not resting on its laurels with Wegovy as it also has in phase 3 development CagriSema, a fixed-dose combination of semaglutide and a novel amylin analogue, cagrilintide. The Danish pharma has previously said it expects CagriSema and amycretin to achieve better weight loss results than Wegovy.

Lilly is also developing the GIP/GLP-1/glucagon receptor agonist retatrutide, which is currently in phase 3. Both Lilly and Novo each have three other obesity drugs in phase 2.