Written by: David Cosgrove, MD
Sponsored by: Takeda
Treatment algorithms for patients with metastatic colorectal cancer (mCRC) have become increasingly complex in recent years, as new drug approvals have created additional therapeutic avenues for specific subsets of patients.1 Traditionally, mCRC patients who are fit enough for active therapy would undergo combination cytotoxic chemotherapy utilizing a fluoropyrimidine backbone, until disease progression or unacceptable toxicity. There were a limited number of effective agents available, and specific combinations were selected primarily based on patient comorbidity and toxicity risk, rather than on any tumor-specific factors. Predictably, within this model, response rates were modest and long-term outcomes remained grim.
Today, the majority of mCRC patients will still receive initial treatment with cytotoxic chemotherapy, but diagnostic testing is often incorporated to uncover actionable tumor-specific genomic and/or immune signatures, and these insights may be leveraged to guide the use of specific targeted therapies with improved patient outcomes.2,3,4 Information on tumor mismatch repair status (or microsatellite instability), specific mutations within KRAS/NRAS/BRAF, POLE/POLD-1, overexpression of HER2, and fusions within the NTRK gene all now contribute to treatment decisions at the time of diagnosis and at the time of disease progression where a treatment plan change is indicated. In addition to the recent approval of drugs to target these molecular signatures, an accompanying shift in drug formulation has impacted the mCRC treatment landscape.
Traditional mCRC anticancer agents were formulated for intravenous administration and delivered in an oncology office or hospital infusion suite. Dosing choices, supportive care medications, and treatment adjustments were typically decided by the treating oncologist, in conjunction with infusion nurses and the supporting clinical team; pharmacists played a role in dose confirmation, drug-drug interaction checks and admixture, but direct input beyond that was limited. Today, a majority of the new FDA-approved mCRC therapies are formulated for oral administration. Oral formulations free patients from being tethered to an infusion suite and alter the frequency and personnel involved in treatment touchpoints. The shift to oral formulations has expanded the role of pharmacy teams in patient education, dosing input, dispensing and toxicity assessment, while maintaining their role in drug safety.
Most oncology clinics have had to adapt their staffing and patient flow model to account for this new dynamic. Patient education is a key component to chemotherapy delivery – with traditional intravenous agents, infusion room nurses and oncology nurse educators typically took on this role, performing toxicity assessments and managing side effects chair-side. Traditionally, cytotoxic agents within the same drug class and mechanism of action often exhibited similar toxicity profiles, further simplifying toxicity risk assessments and corresponding patient education. With today’s newer, oral formulations, mechanisms of action and toxicity profiles are more varied – some retain cytotoxic effects, such as capecitabine or tipiracil/trifluridine, whereas others carry very specific toxicity profiles.
As patients may no longer receive treatment in an infusion suite, a significant portion of the responsibility for providing patient-level therapeutic education has been transferred to the pharmacist and pharmacy team. This educational role may be replicated through a series of subsequent treatments, as newer agents are typically delivered sequentially to these patients in later lines of therapy, depending on patient functional status, and suitability for ongoing treatment. Equally as important as pre-treatment education, on-therapy toxicity assessments and potential dose adjustments are now typically shared responsibilities between the treating physician and pharmacy team, and often incorporate patient reported outcomes (PROs) or electronic patient reported outcomes (ePROs)5, as the patient is taking these medications at home, and not under the direct supervision of an infusion nurse team as with the intravenous therapies.
Today’s mCRC treatment model requires close collaboration between the treating oncologist, who has typically developed a long-term therapeutic relationship with the patient and has knowledge of patient-specific factors that will influence treatment tolerance and potential side effects, and the pharmacy team. Lack of a robust communication system and/or improper delegation of tasks pose significant risks to the vulnerable mCRC patient population. To this end, many centers have developed Medically Integrated Pharmacies (MIP) for specialized oncology drugs, which provide direct oversight of quality and safety metrics, enhance adherence, reduce the risk of access delays and deliver appropriate patient-centered care. In our practice, we have seen countless examples of the MIP team lowering barriers to access, expediting delivery and intervening with dose adjustments or concomitant medication changes to ensure our mCRC patients glean as much benefit from their therapies as possible, while maintaining their desired quality of life in the face of a devastating illness.
As crucial as these aspects of care are for the treatment team, financial risk is a major concern for the mCRC patients themselves. Most of the newer therapies approved in the mCRC space in recent years are high-cost agents, and unlike intravenous agents, which were delivered in a medical facility and therefore covered under the medical benefit portion of a patient’s health insurance plan, oral formulation drugs fall under the pharmacy benefit. While we have seen fewer outright denials of coverage for clinically appropriate drugs, challenges remain such as prior authorization, onerous paperwork and especially patient co-payment requirements.
Unfortunately, a number of my patients have also faced barriers from their insurance-mandated, Limited Distribution Network (LDN), which incorporates an external Pharmacy Benefit Manager (PBM) and requires dispensing through a mail-order specialty pharmacy.6 The inability to communicate closely with LDNs and PBM-mandated third-party decision makers has proven challenging – without an on-site team to understand the specifics of a patient’s case, treating providers have limited ability to control dosing adjustments, maintain drug supply and limit care delays. Care delays pose very serious risks, especially in the later stages of mCRC during which dosing flexibility is critical and the majority of patients require dose holds or adjustments on a regular basis. While this issue remains to be solved, having an active MIP in a treatment center with dedicated staff to facilitate co-pay assistance and access to manufacturer- or foundation-level support has proven instrumental in many practices. This resource helps alleviate financial burden and ensures the patient is not forced to make therapy choices based on ability to pay when facing this illness.
In summary, therapeutic management of mCRC has become increasingly complex in recent years. The introduction of new therapeutic agents offers renewed hope for patients dealing with this devastating disease, while simultaneously requiring oncology practices to adjust treatment team infrastructure, and has shifted the onus of delivering patient education to the pharmacy team, who must work in close collaboration with the treating physician. Today’s shift to oral drug formulations introduces financial risks for patients, as at-home medications fall under a prescription drug benefit which may introduce additional barriers such as may PBM-mandated LDNs or specialty pharmacy requirements. The creation of MIPs has significantly enhanced provider communication, reduced barriers to access, expedited therapy delivery, and supported timely dose adjustments or medication changes to help mCRC patients gain the most benefit from treatment. MIPs have also been essential in building a broader administrative team focused on ensuring patients receive maximum benefit from breakthrough anticancer agents, while minimizing both physical and financial toxicity.
References:
- https://www.nccn.org/professionals/physician_gls/pdf/colon.pdf
- Yaeger R, Weiss J, Pelster M, et al. Adagrasib with or without Cetuximab in colorectal cancer with mutated KRAS G12C. N Engl J Med 2023;388:44-54
- Kopetz S, Yoshino T, Cutsem EV, et al. Encorafenib, cetuximab and chemotherapy in BRAF-mutant colorectal cancer: a randomized phase 3 trial. Nat Med 2025
- Overman MJ, Lonardi S, Wong K, et al. Durable clinical benefit with nivolumab plus ipilimumab in DNA mismatch repair-deficient/microsatellite instability-high metastatic colorectal cancer. J Clin Oncol 2018;36:773-779
- Basch E, Deal A, et al. Overall survival results of a trial assessing patient-reported outcomes for symptom monitoring during routine cancer treatment. JAMA 2017 July 11;318(2):197-198
- https://www.ncoda.org/oold/
