---
schema_version: "secwatch.filing_event.v1"
accession: "0001104659-22-082470"
form_type: "8-K"
ticker: "RIGL"
cik: "0001034842"
company_name: "RIGEL PHARMACEUTICALS INC"
filed_at: "2022-07-25T23:59:59+00:00"
generated_at: "2026-06-24T09:01:52.841015+00:00"
event_type: "litigation"
sentiment: "neutral"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# Rigel files patent lawsuit against Annora to block generic TAVALISSE

## Summary
- Filed suit in U.S. District Court for New Jersey against Annora Pharma, Hetero Labs, and Hetero USA for patent infringement.
- Lawsuit responds to Annora's ANDA seeking FDA approval for a generic version of TAVALISSE (fostamatinib).
- Annora sent Paragraph IV Notice Letter in June 2022 alleging the five asserted patents are invalid or not infringed.
- Asserted patents: 7,449,458, 8,263,122, 8,652,492, 8,771,648, and 8,951,504 listed in the FDA Orange Book.
- Rigel seeks equitable relief to enjoin Annora from infringing the patents covering TAVALISSE.

## SEC filing metadata
- accession: 0001104659-22-082470
- form_type: 8-K
- ticker: RIGL
- cik: 0001034842
- company_name: RIGEL PHARMACEUTICALS INC
- filed_at: 2022-07-25T23:59:59+00:00
- event_type: litigation
- sentiment: neutral
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 8.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1034842/000110465922082470/0001104659-22-082470-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1034842/000110465922082470/tm2221725d1_8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001104659-22-082470
- JSON: https://secwatch.observer/filing/0001104659-22-082470.json
- Plain text: https://secwatch.observer/filing/0001104659-22-082470.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.