Pfizer (PFE.N) plans to move a reworked, once-a-day version of its weight-loss pill danuglipron into clinical trials later this year, the company said on Thursday, after scrapping a twice- daily version of the drug late last year.

The new drug is part of the second generation of weight-loss pills under development by companies including Eli Lilly (LLY.N) and Novo Nordisk (NOVOb.CO) that will offer patients a more convenient alternative to injections.

Some analysts expect the weight-loss drug market, currently dominated by Novo Nordisk’s Wegovy and Eli Lilly’s Zepbound, to be worth more than $150 billion in annual sales by the early 2030s.

The drugmaker did not lay out an exact timeline for development of the drug. It plans to evaluate multiple doses of the reformulated drug in the second half of this year before advancing it into clinical trials.

Pfizer last year said it was focusing on the development of the new version of danuglipron after it scrapped the twice-daily version because most patients dropped out of its mid-stage trial with high rates of side effects such as nausea and vomiting.

It had already dropped another daily weight-loss drug, called lotiglipron, due to safety concerns as it raised levels of liver enzymes in some patients.

JP Morgan analyst Chris Schott said in a research note that Eli Lilly’s experimental weight-loss pill has a significant time-to-market advantage over Pfizer’s and he was still concerned about side-effects from the drug.

He said he sees “a limited role for the asset absent more clarity on the tolerability profile of the new formulation.”

Shares of Pfizer rose 2.8% to $29.14 in premarket trading.

The shares closed at $28.35 on Wednesday and have lost more than half of their value since hitting $61 in December 2021, due to a steep drop in sales of its COVID products and investor worries over its pipeline including lotiglipron.

Pfizer said on Thursday early study results supported a once-daily dosing, with no liver enzyme elevations observed in more than 1,400 healthy adult volunteers.

GLP-1s, originally developed for type 2 diabetes, mimic the action of the GLP-1 hormone to regulate blood sugar, slow digestion and suppress appetite.

Other companies working on next-generation weight loss drugs include Amgen (AMGN.O) and Viking Therapeutics (VKTX.O).

Sales of Pfizer’s COVID-19 vaccine and pill have fallen drastically from their peak during the pandemic, putting pressure on CEO Albert Bourla to drive growth through newer drugs.

The company on Tuesday announced that chief scientific officer Mikael Dolsten would step down after a more than 15-year stint with Pfizer.