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Merck's Welireg Approved: Tumor Shrinkage Breakthrough, Risks Remain

5/15/2025

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Summary

Story summary

Merck & Co. has secured FDA approval for Welireg (belzutifan), a groundbreaking pill for treating advanced pheochromocytoma and paraganglioma in patients aged 12 and older. Clinical trials revealed an impressive 26% tumor shrinkage, with effects lasting over 20 months. However, potential risks like severe anemia and pregnancy complications loom large.

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Story summary

Merck & Co. has secured FDA approval for Welireg (belzutifan), a groundbreaking pill for treating advanced pheochromocytoma and paraganglioma in patients aged 12 and older. Clinical trials revealed an impressive 26% tumor shrinkage, with effects lasting over 20 months. However, potential risks like severe anemia and pregnancy complications loom large.