13 years after Roche halted its GLP-1 drug trials due to side effects, it's making a $3.1B acquisition to get back in the weight loss game.

Today's acquisition of Carmot Therapeutics and its portfolio of GLP-1 candidates shows just how hot the market is for weight loss drugs.

While Novo Nordisk and Eli Lilly and Company have a commanding lead, others are jumping into the race - here's a recap of the most recent entrants and their their development status:

Roche: Roche's $3.1 billion dollar acquisition of Carmot puts it back in the GLP-1 game more than a decade after it paused trials of a previous medicine, taspoglutide, back in 2010 due to serious gastrointestinal side effects. It's a reminder that the craze for obesity drugs today comes after many years of failures to get an effective treatment with tolerable side effects.

Name: CT-388; CT-996; CT-868

Deal value: $2.7 billion upfront, plus $400 million based on milestones

Dosage form:
CT-388: Injectable, once weekly
CT-996: Oral pill once daily
CT-868: Injectable, once daily

Phase:
CT-388: Phase 2 ready
CT-996: Phase 1
CT-868: Phase 2

Acquisition Target: Carmot Therapeutics

AstraZeneca's November deal with China's Eccogene gave it exclusive global rights for development and commercialization worldwide except China, where it will share rights with Eccogene. One notable aspect of the deal was the increased profile of Shanghai, China based Eccogene, which is only 5 years old.

Name: ECC5004

Deal value: $185 million upfront, plus up to $1.825 billion based on milestones

Dosage form: Oral pill, once daily

Phase: Phase 1

Partner: Eccogene

Boehringer Ingelheim's ongoing partnership with Zealand resulted in a promising GLP-1 class drug that demonstrated an up to 19% reduction in weight after 46-weeks in a recent trial. The German drugmaker is planning to conduct three late-stage trials to further advance the drug towards market.

Name: Survodutide

Deal value: N/A - result of multi-year collaboration with multiple research targets

Dosage form: Injectable, once weekly

Phase: Phase 3 trial currently being enrolled

Partner: Zealand Pharma

Merck: Merck has recently made continued strides in the development of efinopegdutide, a promising drug initially targeted for treating Nonalcoholic Fatty Liver Disease (NAFLD). Interestingly, efinopegdutide belongs to a class of drugs also used in treating obesity, positioning Merck at the threshold of the burgeoning obesity drug market. For NAFLD itself, Merck's drug outperformed Ozempic by achieving a higher mean reduction in liver fat content of 72.7% vs 42.3%.

Name: Efinopegdutide

Deal value: $10 million upfront, plus up to $860 million based on milestones

Dosage form: Injectable, once weekly

Phase: Phase 2

Partner: Hanmi Pharmaceutical

Pfizer's efforts in the space recently suffered a slight setback with a Phase 2b trial for its twice daily oral drug Danuglipron having high rates of adverse reactions, causing more than half of participants to drop out of the trial. Pfizer has previously said that it believes its oral obesity pills could eventually generate more than $10 billion in potential revenue. Pfizer plans to drop the twice daily version and instead focus on a once-daily formulation of danuglipron that has reduced side effects.

Name: Danuglipron

Deal value: N/A, developed in-house

Dosage form: Oral pill, once daily

Phase: Phase 1

Partner/Acquisition Target: N/A, developed in-house