Treatment journey 
for CASGEVY^® one-time infusion for patients aged 12 years or older with SCD or TDT

Voice-over:

Discover the process for manufacturing and quality testing of CASGEVY (exagamglogene autotemcel): a first-of-its-kind, CRISPR/Cas9-modified cellular gene therapy.

The “Manufacturing and Quality” step of the CASGEVY treatment journey is a complex process.

This video will provide a closer look at what happens in the Vertex manufacturing facilities where CASGEVY is produced for your patient.

It takes approximately 5-6 months to manufacture and quality test CASGEVY before it is sent back to your Authorized Treatment Center (ATC) for administration.

INDICATION

CASGEVY is indicated for the treatment of patients aged 12 years and older with:

• sickle cell disease (SCD) with recurrent vaso-occlusive crises (VOCs)
• transfusion-dependent β-thalassemia (TDT)

IMPORTANT SAFETY INFORMATION

WARNINGS AND PRECAUTIONS

Neutrophil Engraftment Failure

There is potential risk of neutrophil engraftment failure after treatment with CASGEVY. In the clinical trials, all treated patients achieved neutrophil engraftment and no patients received rescue CD34⁺ cells.

Monitor absolute neutrophil counts (ANC) and manage infections according to standard guidelines and medical judgement. In the event of neutrophil engraftment failure, patients should be infused with rescue CD34⁺ cells.

Delayed Platelet Engraftment

Delayed platelet engraftment has been observed with CASGEVY treatment. There is an increased risk of bleeding until platelet engraftment is achieved. In the clinical trials, there was no association observed between incidence of bleeding events and time to platelet engraftment.

Monitor patients for bleeding according to standard guidelines and medical judgement. Conduct frequent platelet counts until platelet engraftment and platelet recovery are achieved. Perform blood cell count determination and other appropriate testing whenever clinical symptoms suggestive of bleeding arise.

Hypersensitivity Reactions

Hypersensitivity reactions, including anaphylaxis can occur due to dimethyl sulfoxide (DMSO) or dextran 40 in the cryopreservative solution. Monitor patients for hypersensitivity reactions during and after infusion.

Off-Target Genome Editing Risk

Although off-target genome editing was not observed in the edited CD34⁺ cells evaluated from healthy donors and patients, the risk of unintended, off-target editing in an individual’s CD34⁺ cells cannot be ruled out due to genetic variants. The clinical significance of potential off-target editing is unknown.

Please see additional Important Safety Information in this video and accompanying full Prescribing Information.

After it is determined that your patient is appropriate for CASGEVY, they will start the cell collection process.

Your patient will be required to undergo mobilization followed by apheresis at an ATC to collect as many CD34⁺ hematopoietic stem cells (HSCs) as possible for CASGEVY manufacturing.

Following apheresis, the collected CD34⁺ cells are immediately stored at 2-8 °C in a sterile collection bag and transported to the Vertex manufacturing site. Cells are shipped at the end of Day 1 and Day 2 of collection.

A GPS tracker allows the cells to be monitored as they are transported via courier.

The hold time, or the amount of time between the end of apheresis and the start of manufacturing, should be no more than 58 hours.

During this time frame, cell temperature is maintained at 2-8 °C.

Controlling hold times and maintaining optimal temperatures are important to ensure both the quality and number of cells entering the manufacturing process.

Upon arrival at the manufacturing facility, the collection bags are handled in highly controlled, sterile environments throughout the entire process to reduce any potential risk of contamination.

The collection bags are gradually transferred step-wise through increasingly higher-classification cleanrooms—controlled environments used for manufacturing that filter airborne pollutants like dust and microbes to provide the cleanest area possible.

Strict sanitation procedures for the collection bag occur at each step, until the “sterile core,” the cleanest part of the facility where the gene-editing process takes place, is reached.

Rigorous chain of identity and custody procedures are employed during each step of the manufacturing and quality testing process to ensure your patient receives their edited cells back for infusion.

Our procedures include utilizing unique identification codes, temperature monitoring, GPS trackers, and meticulous documentation of the cells’ location, date, and time of possession.

Once inside the sterile core, the gene-editing process, which takes approximately 6 days, can begin.

CD34⁺ cells now need to be isolated from each collection bag to ensure the enriched CD34⁺ cells advance through the manufacturing process.

This is done using a closed, automated, sterile CliniMACS Prodigy^® Instrument to label the CD34⁺ cells with paramagnetic microbeads conjugated to a monoclonal antibody directed against CD34.

The labeled CD34⁺ cells are then selected in the presence of a magnetic field using an automated cell separation system.

This process is repeated for each collection bag retrieved from your patient.

After each individual collection bag undergoes the isolation process, all isolated CD34⁺ cells are combined into one bag.

The combined CD34⁺ cells are then centrifuged to further separate the isolated CD34⁺ cells from the supernatant.

The CD34⁺ cells are cultured in the presence of growth media and incubated, allowing the cells to recover.

To precisely edit the enriched CD34⁺ cells and manufacture CASGEVY, a CRISPR/ Cas9 complex consisting of Cas9 and a single guide RNA (sgRNA) targeting the erythroid-specific enhancer region of the BCL11A gene is utilized.

In order to edit the CD34⁺ cells, the CRISPR/Cas9 complex is introduced nonvirally via electroporation, an established tool in molecular biology utilized to create temporary pores within the cell membrane.

The CD34⁺ cells are centrifuged again and mixed with CRISPR/Cas9 in preparation for electroporation.

The electroporation mixture containing the CD34⁺ cells and CRISPR/Cas9 is then loaded into a cassette and electroporated using an electroporator.

During electroporation, an electrical pulse creates temporary pores within the cell membrane, which allows the CRISPR/Cas9 complex to enter and edit the CD34⁺ cells.

The sgRNA directs the Cas9 enzyme precisely to the erythroid-specific enhancer region of the BCL11A gene and disrupts it, reducing BCL11A expression.

After electroporation, the cells are incubated and allowed to recover in a culture medium.

Following electroporation and the editing process, the edited CD34⁺ cells need to be harvested and prepared to be shipped back to your ATC.

The edited CD34⁺ cells are centrifuged and prepared for cryopreservation until quality testing has concluded.

To prepare for cryopreservation, the edited cells are suspended in a cryopreservative solution containing 5% dimethyl sulfoxide (DMSO).

The cryopreservative solution protects the edited CD34⁺ cells during the freezing step in a controlled rate freezer.

The cryopreservative solution containing the edited CD34⁺ cells is added to pre-assembled, sterile vials with a sterile needle, which are weighed and examined before being carefully sealed with a laser.

Before being frozen, each vial is carefully inspected and properly labeled to comply with our chain of identity and custody procedures.

A controlled rate freeze is used to gradually freeze and cryopreserve the CD34⁺ cells at an appropriate temperature.

This requires a controlled rate freezer to precisely cool the cell mixture at rates that protect the edited CD34⁺ cells from damage or deterioration.

The edited CD34⁺ cells are cooled to 4 °C and slowly brought down to -85 °C before they’re removed from the controlled rate freezer and transferred to storage at or below -135 °C in vapor phase liquid nitrogen until quality testing is complete.

This entire process, from isolating and editing the cells to properly storing them, takes approximately 6 days.

The remainder of the manufacturing process is dedicated to quality release testing to confirm the product meets release criteria.

While the majority of edited CD34⁺ cells are frozen, a small sample is put through a rigorous quality check process.

Gene editing using CRISPR/Cas9 to make CASGEVY is a precise process. Quality release testing is a time-intensive process done to ensure the final product is ready for your patient.

It may take anywhere from 5-6 months to make sure the product passes all the quality criteria, including viability, purity, content, potency, sterility, and other safety release tests.

Innovative, cell-based assays help ensure a high-quality product is delivered to your patients. Some assays require cell culture and differentiation, which can take multiple weeks.

Vertex’s commitment to patient safety drives our rigorous quality release testing process for CASGEVY. This meticulous approach ensures that each dose of CASGEVY meets stringent standards.

Once quality testing is complete and enough CD34⁺ cells have been edited to meet the minimum dose, CASGEVY is ready to be shipped back to your ATC for infusion.

CASGEVY is shipped cryopreserved at or below -135 °C to the ATC in a sealed vapor phase liquid nitrogen dry shipper that is validated for a hold time of at least 10 days.

On receipt, your ATC must check the integrity of the package and verify that the cellular product labels match the patient's unique identifier. Vials should be labeled “for autologous use only” with identification numbers, lot number, and expiration date in accordance with regulatory requirements. The vials will be stored at your ATC until the next step of the treatment journey.

IMPORTANT SAFETY INFORMATION (continued)

ADVERSE REACTIONS

The most common Grade 3 or 4 non-laboratory adverse reactions (occurring in ≥ 25%) were mucositis and febrile neutropenia in patients with SCD and patients with TDT, and decreased appetite in patients with SCD.

All (100%) of the patients with TDT and SCD experienced Grade 3 or 4 neutropenia and thrombocytopenia. Other common Grade 3 or 4 laboratory abnormalities (≥ 50%) include leukopenia, anemia, and lymphopenia.

DRUG INTERACTIONS

No formal drug interaction studies have been performed. CASGEVY is not expected to interact with the hepatic cytochrome P450 family of enzymes or drug transporters.

Use of Granulocyte-Colony Stimulating Factor (G-CSF): G-CSF must not be used for CD34⁺ HSC mobilization of patients with SCD.

Use of Hydroxyurea: Discontinue the use of hydroxyurea at least 8 weeks prior to start of each mobilization cycle and conditioning. There is no experience of the use of hydroxyurea after CASGEVY infusion.

Use of Voxelotor and Crizanlizumab: Discontinue the use of voxelotor and crizanlizumab at least 8 weeks prior to start of mobilization and conditioning, as their interaction potential with mobilization and myeloablative conditioning agents is not known.

Use of Iron Chelators: Discontinue the use of iron chelators at least 7 days prior to initiation of myeloablative conditioning, due to potential interaction with the conditioning agent. Some iron chelators are myelosuppressive. If iron chelation is required, avoid the use of non-myelosuppressive iron chelators for at least 3 months and use of myelosuppressive iron chelators for at least 6 months after CASGEVY infusion. Phlebotomy can be used instead of iron chelation, when appropriate.

USE IN SPECIFIC POPULATIONS

Pregnancy/Lactation: CASGEVY must not be administered during pregnancy and breastfeeding should be discontinued during conditioning because of the risks associated with myeloablative conditioning. Pregnancy and breastfeeding after CASGEVY infusion should be discussed with the treating physician.

Females and Males of Reproductive Potential: A negative serum pregnancy test must be confirmed prior to the start of each mobilization cycle and reconfirmed prior to myeloablative conditioning.

Women of childbearing potential and men capable of fathering a child should use effective methods of contraception from start of mobilization through at least 6 months after administration of CASGEVY. Advise patients of the risks associated with conditioning agents.

Infertility has been observed with myeloablative conditioning therefore, advise patients of fertility preservation options before treatment, if appropriate.

Please see full Prescribing Information for CASGEVY by scanning the QR code or visiting CASGEVYHCP.com.