Rigel receives Paragraph IV notice from Annora for generic TAVALISSE; intends to defend patents

RIGEL PHARMACEUTICALS INC

Annora Pharma filed ANDA with FDA for generic fostamatinib tablets (100mg and 150mg base).
Notice letter includes Paragraph IV certifications alleging Rigel's TAVALISSE patents are invalid or not infringed.
Rigel states it will vigorously enforce its intellectual property rights related to TAVALISSE.
TAVALISSE is Rigel's sole approved product; generic entry would materially impact revenue.

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