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Catalyst pharmaceuticals Exhibit 99.1 Catalyst Pharmaceuticals Reports Third Quarter 2021 Financial Results Continued Strong Financial and Operational Performance in the Third Quarter 2021 FIRDAPSE® Revenue of $ 35.9 Million Increased 23.1 % Compared to Third Quarter 2020 Plans to Seek to Expand the U.S. Approval of FIRDAPSE To Include Pediatric LEMS Patients Strong Cash Position $ 174.8 Million Supports Long - term Growth Strategy Company to Host Quarterly Conference Call on November 10 , 2021 , at 8:30 AM ET CORAL GABLES , Fla . , November 9 , 2021 — Catalyst Pharmaceuticals , Inc. ( Catalyst ) ( Nasdaq : CPRX ) , a commercial - stage , patient - centric biopharmaceutical company focused on in - licensing , developing , and commercializing novel high - quality medicines for patients living with rare diseases , today reported financial results for the third quarter ended September 30 , 2021 , and provided a corporate update . " We delivered another quarter of strong financial results while making important progress on all fronts , " said Patrick J. McEnany , Chairman and CEO of Catalyst . " We reported a record quarter for net sales for FIRDAPSE® , further underscoring the strength of our commercial capabilities while advancing our efforts in support of the orphan drug exclusivity of FIRDAPSE for the treatment of LEMS . We continued to execute on all key growth initiatives , including plans to expand the label for FIRDAPSE to include all LEMS patients , including the very few pediatric patients diagnosed with LEMS . Our quarterly achievements demonstrate continued performance excellence supported by several key strategic decisions that have positioned Catalyst firmly for the future . In saying that , we are excited about the path ahead as we continue to execute across all fronts to drive sustainable growth for the long term . Operational Highlights Achieved record net FIRDAPSE revenue in the third quarter of 2021 of $ 35.9 million driven by strong patient persistency and new patient enrollments , representing a 6.7 % increase compared to the second quarter 2021 . Received favorable decision from the U.S. 11th Circuit Court of Appeals supporting the orphan drug exclusivity for FIRDAPSE® ( amifampridine ) Tablets 10 mg for LEMS treatment in the U.S. Strengthened the intellectual property portfolio for FIRDAPSE with a second patent published in the Orange Book , extending the intellectual property to 2034 , with additional patents pending . 1