recision oncology promises a new model of cancer care where medical decisions are based on a holistic view of the patient, including their genes, environment, and lifestyle, and tailored to the molecular profile of their tumor. To date, great strides toward the paradigm of precision oncology have been made in the area of cancer immunotherapy, which boosts a patient’s own immunity to combat tumor cells. Immune checkpoint inhibitors and chimeric antigen receptor (CAR) T-cell therapies have dramatically improved outcomes for a select number of patients, but widespread use of these treatments remains elusive.
To make personalized cancer treatment a reality for all patients, we need to reimagine the biopharmaceutical business model and drug development process, both of which have traditionally been focused on broad drug development and blockbuster drugs. New regulatory, technical, clinical, and economic frameworks are needed to ensure that the right patient can access the right therapy in a meaningful timeframe. In this article, I discuss three key challenges which must be addressed to fulfill the promise of precision oncology.
Understanding and addressing mechanisms of resistance
The ultimate goal of cancer immunotherapy is to stimulate the immune system to launch a sustained attack against tumor cells. Given the complex and dynamic interactions between tumors and the immune system, achieving this is complicated. The challenge lies in managing the delicate balance between autoimmunity and the immune system’s ability to recognize non-self. In some cases, the immune system may fail to recognize tumor cells as non-self and may develop a tolerance to them. Moreover, tumors have myriad methods for evading the immune system (see Figure 1).
Resistance to cancer immunotherapy can be categorized as primary (i.e., failure to respond) or secondary (i.e., relapse after successful treatment). Approaches for optimizing response and minimizing resistance to cancer immunotherapies include developing biomarkers to assist with patient selection or treatment monitoring, altering the tumor microenvironment, and educating healthcare practitioners on the potential for delayed response with these types of treatments. With CAR-T therapies, resistance may be due to poor persistence of CAR T-cells after infusion or due to antigen loss of the target receptor.
Given the elaborate interplay between cancer and immunity, combination therapies may be a rational approach to addressing resistance. For example:
- Combining two immunotherapies targeting distinct immune checkpoints (see Figure 1)
- Combining an immunotherapy with chemotherapy, which directly kills tumor cells and may help activate the immune system to boost the response to immunotherapy
- Combining an immunotherapy with targeted therapy to create a possible synergistic effect
Solving the logistics of manufacturing
Whereas the conventional manufacturing process is typically confined to a single facility, manufacturing of cell therapies requires multiple hand-offs. While the process begins and ends at the bedside, the process of genetic modification involves a complex chain of custody that blends manufacturing and administration (see Figure 2). The manufacturing process is further complicated by the fact that, unlike traditional manufacturing where the starting materials are standardized, the starting materials for cell therapies are highly variable because they are derived from patients.
As evidenced by the highly publicized manufacturing hurdles surrounding the launch of Kymriah (tisagenlecleucel), meeting label specifications for commercial use is challenging, even for industry leaders. Sponsors must consider how manufacturing will evolve from a single center or investigator-initiated trial to a multi-site commercial endeavor. Proactive planning around logistics is also critical, and the sponsor will need to create an infrastructure for tackling and managing all aspects of chain of custody in a highly controlled manner.
Developing innovative pricing models
Targeted therapies are quite costly in comparison to their traditional counterparts, and existing health insurance models have not been structured to reimburse for these types of treatments. The pricing model for CAR-T therapies may be especially challenging for commercial insurers, which typically have higher turnover and shorter coverage windows than national health insurance programs. Value- or outcomes-based pricing models represent one approach for addressing the challenge of reimbursement. These new pricing models will rely heavily on patient selection, and sponsors will need to develop tools for identifying those patients who are most likely to respond to particular precision medicines.
Notably, the Centers for Medicare & Medicaid Services (CMS) recently finalized their decision to cover FDA-approved CAR-T therapies when provided in healthcare facilities enrolled in the FDA risk evaluation and mitigation strategies (REMS) for FDA-approved indications. Medicare will also cover FDA-approved CAR-T treatments for off-label uses that are recommended by CMS-approved compendia.
Realizing the promise of precision oncology
The precision medicine market is expected to exceed $96 billion by 2024, with the oncology segment of the market leading the way. Patients, providers, and advocacy groups are pushing for innovation, but precision oncology is still in its infancy and significant challenges remain. As advanced technologies and data analytic techniques are increasingly incorporated into the drug discovery and development process, the hope is that precision oncology will not only enable the personalization of cancer treatment, but also improve population health as new genetic and molecular insights enhance our understanding of the mechanisms of disease.