The Coming of Age of Cell-based Therapies
From the AAO-HNS Medical Devices and Drugs Committee Committee Chair and Series Editor: Anand K. Devaiah, MD, Boston University School of Medicine and Boston Medical Center Jennifer Long, MD, PhD UCLA David Geffen School of Medicine and Greater Los Angeles VA Medical Center Otolaryngologists have a number of tools in development that may revolutionize how we practice medicine. Cell and tissue engineering is one of these exciting scientific frontiers deserving special attention by otolaryngologists. The therapeutic potential of isolated cells is a subject of intense investigation, with basic science and translational studies underway in all areas of otolaryngology. Conditions as diverse as hearing loss, vocal fold scar, the aging face, peripheral nerve injury, chronic rhinosinusitis, microtia, cleft palate, and head and neck neoplasms could benefit from cell-based therapies. Concepts for treatment include replacing injured or dysfunctional tissues, delivering a drug or therapeutic molecule directly to the site of interest, and modifying the immune or wound response to attack cancer cells or prevent adverse sequelae from injuries or surgery. We are learning more almost daily about an ever-expanding array of cell-based therapies, their behaviors in culture dishes and in animals, and new methods to generate or analyze them. With so many studies earning attention, otolaryngologists may be left wondering how to employ these emerging treatments for their patients. In reality, of the thousands of proposed ideas, far fewer are currently vetted enough for clinical trials. Thorough animal study and subsequent regulatory review is required to ensure safety and efficacy before advancing to human use, as discussed here. Cell-based therapies, defined as the introduction of cells to humans after some isolation or manipulation ex vivo, are regulated by the FDA. Like traditional pharmaceuticals, they require submission of extensive pre-clinical data in an Investigational New Drug Application, or IND, prior to any human application or clinical trial. However, the standard pre-clinical testing paradigm that has been used for decades in pharmaceutical research (centered on dose response, metabolic kinetics, and toxicities) is often inapplicable to these complex “biological therapeutics.” As such, the FDA has issued special guidance to industry, investigators, and users of cell-based technologies when preparing for clinical trials. The FDA’s Center for Biologics Evaluation and Research (CBER), Office of Cellular, Tissue, and Gene Therapies (OCTGT), published a guidance statement in November 2013 to assist in design and implementation of pre-clinical trials of biological therapies in preparation for IND application.1 The rapid evolution of biological therapies poses challenges from a regulatory standpoint. Each IND is therefore considered in a case-by-case manner, allowing for a more individualized approach than in traditional drug and device applications. Nonetheless, the CBER has identified key objectives for pre-clinical study for new “biological products.” These include: Establishing biological plausibility, feasibility, and safety, including of the route of administration Defining patient selection criteria, starting dose and administration schedule, and outcome and monitoring parameters Identifying any public health risk to healthcare workers or patient contacts The guidelines urge investigators to address these points in animal trials submitted for IND application. Additionally, the pre-clinical study model (animal species and disease model) should be relevant to humans, and the pre-clinical product should be as similar as possible to the intended human product. CBER also issued a draft guidance statement of design considerations for early phase clinical trials, in July 2013.2 In particular, risk-benefit analysis for study participants is stressed, in light of study-related deaths and tumors that occurred in early gene and cell therapy trials. Some level of risk is inherent in studies of new therapies, especially where prior experience in humans is still limited. CBER has acknowledged the need to balance individual risk to study volunteers with potential benefits to the individual and to the greater community. This ethical issue should be considered with each new therapy and trial, including single-patient “emergency” or “compassionate use” applications that do not proceed through standard clinical trial mechanisms. Despite the scientific complexity and uncertainty about long-term risks after implantation, cell-based therapies are now being performed in humans. Trachea tissue has become an unlikely golden child in the tissue-engineering arena, thanks to multiple implantations worldwide. The first recipient of a tissue-engineered organ recently reached five years of survival with her cell-populated bronchus replacement.3 The knowledge gained from these few initial patients is invaluable for promoting the concept of cell-based therapies. Their success should support more widespread introduction of pioneering technologies into carefully planned clinical trials. References 1. Guidance for Industry: Preclinical Assessment of Investigational Cellular and Gene Therapy Products. November 2013. http://www.fda.gov/BiologicsBloodVaccines/GuidanceComplianceRegulatoryInformation/Guidances/CellularandGeneTherapy/UCM376136.htm 2. Draft Guidance for Industry: Considerations for the Design of Early-Phase Clinical Trials of Cellular and Gene Therapy Products. July 2013. http://www.fda.gov/downloads/BiologicsBloodVaccines/GuidanceComplianceRegulatoryInformation/Guidances/CellularandGeneTherapy/UCM359073.pdf 3. Gonfiotti A, Jaus MO, Barale D, et al. The first tissue-engineered airway transplantation: 5-year follow-up results. The Lancet 2014;383(9913):238-244. Disclosures: Dr. Long is currently an investigator in a clinical trial of a cell-based therapy. The industry sponsor, Fibrocell Technologies, supplies the processed cells. Dr. Long does not receive any compensation or research funds from the sponsor, and holds no financial interest in the company. This is another in a series of articles being produced by the Medical Devices and Drugs Committee, written by committee members, consultants, and invited guests for the AAO-HNS member. Do you have a question or topic we can address that may fall under the committee’s charge? Do you have a comment about an article? Please let us know! Email our coordinator, Harrison Peery, at hpeery@entnet.org and the chair, Anand Devaiah, MD, at anand.devaiah@bmc.org, with the subject line “MDDC question/article,” so we can properly identify and answer your query. We strive to quickly answer our “fan mail.” Please note that we will ask your permission to publish your note, in anonymous or edited form, if it becomes the inspiration for a Bulletin article.
From the AAO-HNS Medical Devices and Drugs Committee
Committee Chair and Series Editor: Anand K. Devaiah, MD,
Boston University School of Medicine and Boston Medical Center
Jennifer Long, MD, PhD
UCLA David Geffen School of Medicine and Greater Los Angeles VA Medical Center
Otolaryngologists have a number of tools in development that may revolutionize how we practice medicine. Cell and tissue engineering is one of these exciting scientific frontiers deserving special attention by otolaryngologists. The therapeutic potential of isolated cells is a subject of intense investigation, with basic science and translational studies underway in all areas of otolaryngology. Conditions as diverse as hearing loss, vocal fold scar, the aging face, peripheral nerve injury, chronic rhinosinusitis, microtia, cleft palate, and head and neck neoplasms could benefit from cell-based therapies. Concepts for treatment include replacing injured or dysfunctional tissues, delivering a drug or therapeutic molecule directly to the site of interest, and modifying the immune or wound response to attack cancer cells or prevent adverse sequelae from injuries or surgery.
We are learning more almost daily about an ever-expanding array of cell-based therapies, their behaviors in culture dishes and in animals, and new methods to generate or analyze them. With so many studies earning attention, otolaryngologists may be left wondering how to employ these emerging treatments for their patients. In reality, of the thousands of proposed ideas, far fewer are currently vetted enough for clinical trials. Thorough animal study and subsequent regulatory review is required to ensure safety and efficacy before advancing to human use, as discussed here.
Cell-based therapies, defined as the introduction of cells to humans after some isolation or manipulation ex vivo, are regulated by the FDA. Like traditional pharmaceuticals, they require submission of extensive pre-clinical data in an Investigational New Drug Application, or IND, prior to any human application or clinical trial. However, the standard pre-clinical testing paradigm that has been used for decades in pharmaceutical research (centered on dose response, metabolic kinetics, and toxicities) is often inapplicable to these complex “biological therapeutics.” As such, the FDA has issued special guidance to industry, investigators, and users of cell-based technologies when preparing for clinical trials.
The FDA’s Center for Biologics Evaluation and Research (CBER), Office of Cellular, Tissue, and Gene Therapies (OCTGT), published a guidance statement in November 2013 to assist in design and implementation of pre-clinical trials of biological therapies in preparation for IND application.1 The rapid evolution of biological therapies poses challenges from a regulatory standpoint. Each IND is therefore considered in a case-by-case manner, allowing for a more individualized approach than in traditional drug and device applications. Nonetheless, the CBER has identified key objectives for pre-clinical study for new “biological products.”
These include:
- Establishing biological plausibility, feasibility, and safety, including of the route of administration
- Defining patient selection criteria, starting dose and administration schedule, and outcome and monitoring parameters
- Identifying any public health risk to healthcare workers or patient contacts
The guidelines urge investigators to address these points in animal trials submitted for IND application. Additionally, the pre-clinical study model (animal species and disease model) should be relevant to humans, and the pre-clinical product should be as similar as possible to the intended human product.
CBER also issued a draft guidance statement of design considerations for early phase clinical trials, in July 2013.2 In particular, risk-benefit analysis for study participants is stressed, in light of study-related deaths and tumors that occurred in early gene and cell therapy trials. Some level of risk is inherent in studies of new therapies, especially where prior experience in humans is still limited. CBER has acknowledged the need to balance individual risk to study volunteers with potential benefits to the individual and to the greater community. This ethical issue should be considered with each new therapy and trial, including single-patient “emergency” or “compassionate use” applications that do not proceed through standard clinical trial mechanisms.
Despite the scientific complexity and uncertainty about long-term risks after implantation, cell-based therapies are now being performed in humans. Trachea tissue has become an unlikely golden child in the tissue-engineering arena, thanks to multiple implantations worldwide. The first recipient of a tissue-engineered organ recently reached five years of survival with her cell-populated bronchus replacement.3 The knowledge gained from these few initial patients is invaluable for promoting the concept of cell-based therapies. Their success should support more widespread introduction of pioneering technologies into carefully planned clinical trials.
References
1. Guidance for Industry: Preclinical Assessment of Investigational Cellular and Gene Therapy Products. November 2013. http://www.fda.gov/BiologicsBloodVaccines/GuidanceComplianceRegulatoryInformation/Guidances/CellularandGeneTherapy/UCM376136.htm
2. Draft Guidance for Industry: Considerations for the Design of Early-Phase Clinical Trials of Cellular and Gene Therapy Products. July 2013. http://www.fda.gov/downloads/BiologicsBloodVaccines/GuidanceComplianceRegulatoryInformation/Guidances/CellularandGeneTherapy/UCM359073.pdf
3. Gonfiotti A, Jaus MO, Barale D, et al. The first tissue-engineered airway transplantation: 5-year follow-up results. The Lancet 2014;383(9913):238-244.
Disclosures: Dr. Long is currently an investigator in a clinical trial of a cell-based therapy. The industry sponsor, Fibrocell Technologies, supplies the processed cells. Dr. Long does not receive any compensation or research funds from the sponsor, and holds no financial interest in the company.
This is another in a series of articles being produced by the Medical Devices and Drugs Committee, written by committee members, consultants, and invited guests for the AAO-HNS member. Do you have a question or topic we can address that may fall under the committee’s charge? Do you have a comment about an article? Please let us know! Email our coordinator, Harrison Peery, at hpeery@entnet.org and the chair, Anand Devaiah, MD, at anand.devaiah@bmc.org, with the subject line “MDDC question/article,” so we can properly identify and answer your query. We strive to quickly answer our “fan mail.” Please note that we will ask your permission to publish your note, in anonymous or edited form, if it becomes the inspiration for a Bulletin article.