CRSP & Sirius Begin Dosing in Thromboembolic Disorder Study in EU

CRISPR Therapeutics CRSP, along with privately held biotech, Sirius Therapeutics, announced the dosing of the first patient in a phase II study evaluating SRSD107, a next-generation, long-acting siRNA therapy for treating thromboembolic disorders in Europe.

SRSD107 targets Factor XI to treat thromboembolism, which affects millions of people across the world.

The ongoing randomized, multicenter phase II study is assessing the safety and efficacy of SRSD107 for the prevention of venous thromboembolism (VTE) in patients undergoing total knee arthroplasty (TKA).

Year to date, shares of CRISPR Therapeutics have rallied 57.7% compared with the industry’s rise of 3.5%.

CRSP's Recent Deal With Sirius Therapeutics

In May 2025, CRISPR Therapeutics entered into a collaboration deal with Sirius Therapeutics for developing and commercializing novel siRNA therapies.

Per the deal terms, the companies will jointly develop SRSD107 and share all costs and profits equally. Upon potential approval, CRISPR Therapeutics will be responsible for commercializing the drug in the United States and Sirius Therapeutics in Greater China.

CRSP will also have an option to exclusively license up to two siRNA programs. It will solely fund research activities and retain opt-in rights to lead clinical development and commercialization for each target. Sirius Therapeutics will be entitled to receive milestone payments and tiered royalties on net sales.

If successfully developed, SRSD107 has the potential to be a best-in-class therapy for patients who are at risk of life-threatening thromboembolic events due to underlying co-morbid diseases such as malignancy, cardiovascular disease and hyper-coagulability.

The collaboration with Sirius Therapeutics has helped CRISPR Therapeutics diversify its pipeline beyond gene therapies and into RNA therapeutics.

CRSP's Casgevy Sales Gain Momentum

CRISPR Therapeutics and partner Vertex Pharmaceuticals’ VRTX one-shot gene therapy, Casgevy, was approved in late 2023 and early 2024 across the United States and Europe for two blood disorder indications — sickle cell disease (SCD) and transfusion-dependent beta-thalassemia (TDT).

VRTX leads global development, manufacturing and commercialization of Casgevy and splits program costs and profits worldwide with CRSP in a 60:40 ratio.

Though Casgevy’s sales started slowly, they are gaining momentum over time. In its second-quarter 2025 earnings release, Vertex recorded $30.4 million in product revenues from Casgevy sales, compared with $14.2 million in the previous quarter.

CRISPR Therapeutics is also advancing multiple next-generation gene-edited cell therapy programs, including allogeneic chimeric antigen receptor T cell, or CAR T, candidates for the treatment of hematological and solid tumor cancers and other autoimmune diseases.

CRSP's Zacks Rank & Stocks to Consider

CRISPR Therapeutics currently carries a Zacks Rank #3 (Hold).

Some better-ranked stocks in the biotech sector are Akero Therapeutics AKRO and Adaptive Biotechnologies ADPT, each carrying a Zacks Rank #2 (Buy) at present. You can see the complete list of today’s Zacks #1 Rank (Strong Buy) stocks here.

In the past 60 days, estimates for Akero Therapeutics’ 2025 loss per share have narrowed from $3.93 to $3.74. Loss per share estimates for 2026 have narrowed from $4.27 to $4.12 during the same period. AKRO stock has surged 66.8% year to date.

Akero Therapeutics’ earnings beat estimates in three of the trailing four quarters while missing the same on the remaining occasion, the average surprise being 49.24%.

In the past 60 days, estimates for Adaptive Biotechnologies’ 2025 loss per share have narrowed from 87 cents to 71 cents. Loss per share estimates for 2026 have narrowed from 65 cents to 60 cents during the same period. ADPT stock has soared 132.5% year to date.

Adaptive Biotechnologies’ earnings beat estimates in each of the trailing four quarters, the average surprise being 23.99%.

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This article originally published on Zacks Investment Research (zacks.com).

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