On November 18, 2025, ToolGen, Inc. (“ToolGen”) filed a complaint (“Complaint”) in the District of Massachusetts alleging infringement of its U.S. Patent No. 12,473,559 (“the ’559 patent”) by Vertex Pharmaceuticals and related entities involved in the development and manufacture of the gene-edited therapy Casgevy^® (exagamglogene autotemcel). ToolGen, Inc. v. Vertex Pharmaceuticals Inc., et al., No. 1:25-cv-13441 (D. Mass.).

In its Complaint, ToolGen alleges that the Defendants have infringed the ’559 patent by manufacturing, importing, offering for sale, and/or selling Casgevy^® in the United States. The ’559 patent claims methods for inducing genomic modification in human cells using Cas9/sgRNA ribonucleoprotein (RNP) complexes, including preparation of Cas9 with nuclear localization signals, chemically synthesized sgRNA, in vitro RNP complex formation under defined stoichiometric ratios, and electroporation-based delivery to human cells.

Casgevy^® is an autologous hematopoietic stem-cell gene therapy edited ex vivo using the CRISPR/Cas9 platform to disrupt a regulatory element of the BCL11A gene, thereby increasing fetal hemoglobin (HbF) levels in patients. Casgevy^® is FDA-approved for treatment of sickle cell disease (SCD) in patients 12 years and older with recurrent vaso-occlusive crises and for transfusion-dependent β-thalassemia (TDT). According to the Complaint, Defendants collectively manufacture Casgevy^® through a network of U.S. and international facilities, including production of Cas9 protein, synthesis of sgRNA, RNP assembly, and editing of CD34+ hematopoietic stem cells.

ToolGen asserts that these activities infringe at least claim 1 of the ’559 patent under 35 U.S.C. §§ 271(a), (b), (c), and (g).

ToolGen seeks, inter alia, a judgment of infringement and willful infringement, damages (including enhanced damages), attorneys’ fees, and other relief. ToolGen alleges that it has been “substantially and irreparably damaged” as a result of Defendants’ activities.

Casgevy^® generated $10 million in sales in 2024, with projected 2025 sales exceeding $100 million.

For more information on this and other biologic and gene therapy patent disputes, please visit BiologicsHQ.com.

 

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The authors would like to thank April Breyer Menon for her contributions to this article.