KEY TAKEAWAYS

• Incyte led S&P 500 decliners Tuesday afternoon after the pharmaceutical firm said it will stop developing one drug and pause enrollment in the study of another.

• Enrollment in the ongoing Phase 2 trial of a drug to treat chronic spontaneous urticaria (CSU), or chronic hives, was paused.

• The biopharmaceutical firm also said it won't develop the drug to treat cholestatic pruritus (CP), a liver disorder that causes intense itching.

Incyte (INCY) led S&P 500 decliners Tuesday afternoon after the pharmaceutical firm said it will stop developing one drug and pause enrollment in the study of another.

Enrollment in the ongoing Phase 2 trial of MRGPRX2 (INCB000262) in chronic spontaneous urticaria (CSU), or chronic hives, was paused "following the observation of certain in vivo preclinical toxicology findings."

In vivo toxicology is the study of the effect of the toxicity of a drug on a live organism, usually an animal.

Incyte Says It Won't Develop Drug To Treat Intense Itching

It also said data from the Phase 2 study of MRGPRX4 (INCB000547) to treat cholestatic pruritus (CP), a liver disorder that causes intense itching, "does not support further development."

Incyte said it had shared the data with the Food and Drug Administration (FDA) and will work with the agency to "determine next steps."

The company's stock recently was down more than 13%. It is up about 6% this year.