CRISPR Therapeutics Provides Business Update and Reports First Quarter 2019 Financial Results -Enrollment ongoing in Phase 1/2 clinical trials of CTX001 for patients with severe hemoglobinopathies- -IND and CTA approved

CRISPR Therapeutics Provides Business Update and Reports First Quarter 2019 Financial Results

-Enrollment ongoing in Phase 1/2 clinical trials of CTX001 for patients with severe hemoglobinopathies-

-IND and CTA approved for CTX110 , wholly-owned allogeneic CAR-T cell therapy targeting CD19+ malignancies-

-On track to initiate Phase 1/2 clinical trial for CTX110 in 1H 2019-

-$437.5 million in cash as of March 31, 2019-

ZUG, Switzerland and CAMBRIDGE, Mass., April 29, 2019 -- CRISPR Therapeutics (Nasdaq: CRSP), a biopharmaceutical company focused on creating transformative gene-based medicines for serious diseases, today reported financial results for the first quarter ended March 31, 2019.

"This past quarter, we began an important new period for CRISPR Therapeutics with the treatment of the first patient in our clinical trial for CTX001 in hemoglobinopathies," said Samarth Kulkarni, Ph.D., Chief Executive Officer of CRISPR Therapeutics. "This is a significant landmark for the Company and we continue to enroll patients in our trials for both beta thalassemia and sickle cell disease. With the acceptance of our IND and CTA for CTX110, we look forward to the initiation of our clinical trials for our allogeneic CAR-T programs in the near-term and hope to bring other CAR-T programs to the clinic in the next six to twelve months."

Recent Highlights and Outlook

In April 2019, CRISPR Therapeutics and its partner, Vertex, announced that the U.S. Food and Drug Administration (FDA) had granted Fast Track Designation for CTX001, an investigational, autologous, gene-edited hematopoietic stem cell therapy, for the treatment of transfusion-dependent beta thalassemia (TDT). In February 2019, CRISPR and Vertex announced that the first patient had been treated with CTX001 in a Phase 1/2 clinical study of patients with TDT, marking the first company-sponsored use of a CRISPR/Cas9 therapy in a clinical trial. Enrollment in the Phase 1/2 study in patients with TDT is ongoing.

The companies are also evaluating CTX001 for the treatment of sickle cell disease (SCD) and received Fast Track Designation for CTX001 from the FDA in January 2019 for SCD. The companies announced in February 2019 that the first patient had been enrolled in a Phase 1/2 clinical study of CTX001 in severe SCD in the U.S. and is expected to be infused with CTX001 in mid-2019. Enrollment in the Phase 1/2 study in patients with SCD is ongoing.

Earlier this year, the FDA approved CRISPR Therapeutics' Investigational New Drug (IND) application for CTX110, its wholly-owned allogeneic CAR-T cell therapy targeting CD19+ malignancies. Additionally, the Company has obtained approval from Health Canada for its Clinical Trial Application (CTA). CRISPR Therapeutics remains on track to initiate a Phase 1/2 trial to assess the safety and efficacy of CTX110 in the first half of 2019 and continues to work closely with various clinical sites to begin the trial. The Company's proprietary CRISPR-based allogeneic CAR-Ts have the potential to create the next-generation of cell therapies that may have a superior product profile compared to current autologous therapies and allow accessibility to broader patient populations.

First Quarter 2019 Financial Results

About CRISPR Therapeutics

CRISPR Therapeutics is a leading gene editing company focused on developing transformative gene-based medicines for serious diseases using its proprietary CRISPR/Cas9 platform. CRISPR/Cas9 is a revolutionary gene editing technology that allows for precise, directed changes to genomic DNA. CRISPR Therapeutics has established a portfolio of therapeutic programs across a broad range of disease areas including hemoglobinopathies, oncology, regenerative medicine and rare diseases. To accelerate and expand its efforts, CRISPR Therapeutics has established strategic collaborations with leading companies including Bayer AG, Vertex Pharmaceuticals and ViaCyte, Inc. CRISPR Therapeutics AG is headquartered in Zug, Switzerland, with its wholly-owned U.S. subsidiary, CRISPR Therapeutics, Inc., and R&D operations based in Cambridge, Massachusetts, and business offices in London, United Kingdom. For more information, please visit www.crisprtx.com.

CRISPR Forward-Looking Statement

This press release may contain a number of "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including statements regarding CRISPR Therapeutics' expectations about any or all of the following: (i) clinical trials (including, without limitation, the timing of filing of clinical trial applications and INDs, any approvals thereof and the timing of commencement of clinical trials), development timelines and discussions with regulatory authorities related to product candidates under development by CRISPR Therapeutics and its collaborators; (ii) the number of patients that will be evaluated, the anticipated date by which enrollment will be completed and the data that will be generated by ongoing and planned clinical trials, and the ability to use that data for the design and initiation of further clinical trials; (iii) the scope and timing of ongoing and potential future clinical trials; (iv) the intellectual property coverage and positions of CRISPR Therapeutics, its licensors and

third parties; (v) the sufficiency of CRISPR Therapeutics' cash resources; and (vi) the therapeutic value, development, and commercial potential of CRISPR/Cas9 gene editing technologies and therapies. Without limiting the foregoing, the words "believes," "anticipates," "plans," "expects" and similar expressions are intended to identify forward-looking statements. You are cautioned that forward-looking statements are inherently uncertain. Although CRISPR Therapeutics believes that such statements are based on reasonable assumptions within the bounds of its knowledge of its business and operations, forward-looking statements are neither promises nor guarantees and they are necessarily subject to a high degree of uncertainty and risk. Actual performance and results may differ materially from those projected or suggested in the forward-looking statements due to various risks and uncertainties. These risks and uncertainties include, among others: the outcomes for each CRISPR Therapeutics' planned clinical trials and studies may not be favorable; that one or more of CRISPR Therapeutics' internal or external product candidate programs will not proceed as planned for technical, scientific or commercial reasons; that future competitive or other market factors may adversely affect the commercial potential for CRISPR Therapeutics' product candidates; uncertainties inherent in the initiation and completion of preclinical studies for CRISPR Therapeutics' product candidates; availability and timing of results from preclinical studies; whether results from a preclinical trial will be predictive of future results of the future trials; uncertainties about regulatory approvals to conduct trials or to market products; uncertainties regarding the intellectual property protection for CRISPR Therapeutics' technology and intellectual property belonging to third parties; and those risks and uncertainties described under the heading "Risk Factors" in CRISPR Therapeutics' most recent annual report on Form 10-K, and in any other subsequent filings made by CRISPR Therapeutics with the U.S. Securities and Exchange Commission, which are available on the SEC's website at www.sec.gov. Existing and prospective investors are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date they are made. CRISPR Therapeutics disclaims any obligation or undertaking to update or revise any forward-looking statements contained in this press release, other than to the extent required by law.

CRISPR Therapeutics AG

Condensed Consolidated Statements of Operations

(Unaudited, In thousands except share data and per share data)

CRISPR Therapeutics AG

Condensed Consolidated Balance Sheets Data

(Unaudited, in thousands)

WCG on behalf of CRISPR