Therapeutic Interchange Programs Rapidly Growing Across Oncology  

Updated on June 16, 2022
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By Kaci Dominguez, senior director of Pharmacy Solutions for The US Oncology Network

Over the last five to ten years, therapeutic interchange (TI) programs have soared in oncology, as more and more drugs have been approved with similar efficacy and indications to those already on the market. Before then, the oncology landscape was mostly comprised of novel agents with fewer alternatives with comparable efficacy from which to choose. 

Driven by efforts to reduce patient costs and total healthcare spending, TI is now common in oncology. Given the widespread prevalence of these programs, it is worth examining the many benefits TI delivers to oncology stakeholders, as well as the critical role oncology pharmacy plays in developing and managing these vital programs.

Pharmacists are key players in oncology TI 

Oncology pharmacists are uniquely positioned to develop and manage TI programs for many reasons. First, their training and education enable them to evaluate the efficacy and safety of comparable drugs, as that skill set is at the core of pharmacy education. Second, pharmacists are respected members of the multi-disciplinary team and excel at presenting recommendations. In most practices, they already work with physicians on a regular basis and present to the practice’s Pharmacy and Therapeutics (P&T) committee, where the practice’s medication policy is decided. 

Third, and very importantly, they are already placed in the workflow of how drugs are ordered, so they are in the right place at the right time to efficiently make the interchange. In most oncology clinics, a chemotherapy order is reviewed by a pharmacist before it goes further in the process and reaches the patient. The pharmacist is in the best place within the workflow to make a change, if needed, to a comparable drug with lower cost, fewer barriers to access or improved efficacy.

Pharmacists have a long history of developing and managing TI programs in the acute hospital setting, so expanding that concept from hospitals to outpatient oncology is a natural extension. Auto-substitution policies and collaborative practice agreements are tools that practices can implement to enhance the efficacy of TI programs. Pharmacists have been employing these tools in other settings for years, such as for anticoagulation management, and the same principles apply to oncology. These agreements or policies give the pharmacist a very specific scope of which decisions they can make independently without directly talking to the physician. One example is switching to preferred agents, that were previously approved by the P&T Committee. The pharmacist has some independence to make that decision, but the scope is usually limited and tightly defined. In cases with more complexity, pharmacists discuss their recommendations directly with the physician before implementing the changes.

How pharmacists evaluate interchanges

Pharmacists employ a careful decision-making process when evaluating therapeutic interchanges. The main priority and the very first step in the TI process is to identify agents with equal efficacy that deliver good outcomes for the patient. The goal is to ensure outcomes are maintained or improved if an alternative is chosen.

Once the efficacy hurdle is met, other factors come into play, such as payer restrictions, cost for the patient, and financial impact for the practice. Efficacy and delivering the best possible patient outcomes are always the priorities, as they should be.

Many benefit from oncology TI programs

Therapeutic interchange programs can provide value to all oncology stakeholders. Perhaps the biggest benefit to patients is the lower cost of therapy, reducing the financial burden many encounter. Along with reduced cost comes improved access to care, as limited financial resources can inhibit the patient’s ability to start a therapy or continue treatment. From our experience across The US Oncology Network, in many cases TI has allowed financially challenged patients to access their medications and continue them for a longer period of time. Increasing adherence drives and supports better patient outcomes.1-2

Thoughtfully designed TI programs also benefit the practice. By ensuring a pharmacist reviews the order early in the workflow, TI programs can save time downstream by preventing rework if the drug order needs to be changed. 

Practices may also realize a financial benefit from a TI program. Sometimes a practice can profit by using a certain drug over another even when the cost to the patient is similar.

Therapeutic interchange also supports practice compliance with value-based care programs. For instance, the Oncology Care Model (OCM), a pilot program from the Centers for Medicare & Medicaid Services Innovation Center, incentivized practices to use lower cost therapies while providing higher-quality, better-coordinated care. The government is continuing its goal to transition healthcare to value-based care with various new reimbursement models, and many commercial payers are following the same path. Being able to comply with these new programs is a huge benefit that TI programs deliver back to the practice.

Additionally, practices benefit by allowing pharmacists to take on the time-consuming burden of developing and managing these complex programs, freeing up the physician’s schedule for patient care—always the main priority.

Lastly, payers also gain benefits from cost savings delivered through TI, as these programs provide the opportunity to lower total cost of care while still ensuring members receive high-quality effective therapies. 

Challenges to therapeutic interchange

While TI programs are becoming more common in oncology, there are still some major hurdles that practices must overcome when developing and managing a program. The first is payer restrictions. Commercial payers may have certain preferred drugs within a class they want providers to use for their patients, and that makes it more difficult to develop and implement TI programs consistently. Pharmacists must constantly be aware of the insurance the patient has and whether that insurer has specific restrictions. 

Additionally, biosimilars are dramatically impacting the healthcare landscape, delivering a roughly 30 percent discount over brand biologics in the U.S., with the potential to decrease spending by as much as $100 billion over the next five years.3 Biosimilars are approved through a different pathway than traditional generic drugs and switching studies are not required. Most agree there is probably no reason to be concerned, however, the lack of interchangeability studies can be an issue in some cases. Also, the rapid pace of new biosimilars coming to market makes it difficult to continually modify TI programs to ensure the best biosimilar is on the preferred drug list.

Some challenges that were common 10 or 15 years ago have been overcome. For instance, physicians were often reluctant to allow pharmacists to do this type of interchange. Due to the rising complexity of cancer care and a better understanding of pharmacists’ expertise, physicians now seek out a pharmacist’s intervention to ensure high-quality, cost-effective care. 

Managing payer step edits 

Oncology pharmacists play a key role in dealing with payer step edits that can inhibit timely care. Payer coverage rules are becoming increasingly more complex, especially for biosimilars. As there are no biosimilars in oncology that have an interchangeability designation, an intervention by a pharmacist or other healthcare provider is required. 

Pharmacists are highly qualified to lead TI programs 

Therapeutic interchange programs driven by pharmacists are very common in many medical settings all across the healthcare landscape, and they are very well executed. These programs are now widespread within community oncology and undoubtedly will grow even more as cancer care continues to transition to more cost-effective, value-based care.

Oncology pharmacists are uniquely positioned to do this type of work, as they have extensive education and training in both medicinal chemistry and pharmacology, enabling them to evaluate the scientific data behind various therapies to navigate complex drug choices. Developing and managing TI programs allow these highly specialized pharmacists to use the vast knowledge they have acquired to improve patient outcomes, playing a key role in providing high-quality, cost-effective care.


1. Sabaté E. Adherence to long-term therapies: Evidence for action.Geneva: World Health Organization.2003.;jsessionid=5B8E7E01031EB9D743CBA1BE5D9530C8?sequence=1.Accessed May 18, 2022.

2. Kim J, et all. Medication Adherence: The Elephant in the Room. Medication Management. January 19, 2018. room#:~:text=Medication%20adherence%20can%20affect%20quality,outcomes%2C%20and%20overall%20healthcare%20costs.&ext=Nonadherence%20can%20account%20for%20up,year%20in%20the%20United%20States. Accessed May 18, 2022.

3. Andrews M. Biosimilar drugs are cheaper than biologics. Are they similar enough to switch? Kaiser Health News. September 23, 2021.,brand%20biologic%20to%20a%20biosimilar. Accessed April 3, 2022.

The Editorial Team at Healthcare Business Today is made up of skilled healthcare writers and experts, led by our managing editor, Daniel Casciato, who has over 25 years of experience in healthcare writing. Since 1998, we have produced compelling and informative content for numerous publications, establishing ourselves as a trusted resource for health and wellness information. We offer readers access to fresh health, medicine, science, and technology developments and the latest in patient news, emphasizing how these developments affect our lives.