Evaluating a Digital Tool for Monitoring Drug Toxicities in Patients With Colorectal Cancer

Insights From the 2022 ASCO Quality Care Symposium

Dose modifications and toxicity management are common challenges associated with administering cancer therapies, particularly among patients treated in the outpatient setting.

In a recent feasibility study, Dr Reetu Mukherji and coinvestigators evaluated whether a smartphone application could be used for monitoring patients with metastatic colorectal cancer who started treatment with regorafenib. Dr Mukherji shares the results of the study, which she and her coinvestigators presented at the 2022 ASCO Quality Care Symposium.

What is the CarePrompter smartphone app, and how is it used?

CarePrompter is a novel smartphone application that has patient and provider interfaces. When patients enrolled in our study, a research coordinator downloaded the application on a patient's iOS or Android smartphone. The coordinator trained patients on using the application, including how to record metrics like blood pressure and answer daily questions related to side effects from a particular therapy.

The CarePrompter application prompts patients to answer questions like, did you take your pills for your cancer? If yes, how many? If no, why not? What was your blood pressure range that day? The app also prompts patients to rate predefined symptoms on a scale of 1 to 10, with 10 being worst in severity. CarePrompter asks patients whether they had blood work done that week, saw their provider that week, and have any questions or need advice for managing symptoms.

Oncologists and nurses have access to the application. On the provider interface, they use a triage tool and are alerted to patient responses. For instance, providers are alerted if the patient reports a high blood pressure range or high severity score (8 or higher). If a patient says they did not know to get blood work done or they needed more advice, this will alert the providers, who can address those problems accordingly.

Thank you. What inspired your research into using the CarePrompter app for patients with metastatic colorectal cancer being treated with regorafenib?

In the past decade, numerous oral therapies targeting cancer have received regulatory approval across cancer types. While these therapies can improve survival and oncologic outcomes, they have varying rates of toxicity, and recognizing and managing side effects is important from safety, quality of life, and efficacy standpoints.

We often perform these assessments and have interventions, whether it be holding the drug or modifying the dose, but this is often done during a clinic visit. We may have several days or a week between clinic visits where side effects go untreated. We thought it was important to investigate novel strategies for early recognition and management of outpatient ambulatory drug toxicities.

Regorafenib is an oral multikinase inhibitor that improves survival in colorectal cancer. Regorafenib is approved in patients who have previously been treated with chemotherapy like fluorouracil, oxaliplatin, irinotecan, and biologics like anti-EGFR and anti-VEGF therapies.

The target daily dose of regorafenib is 160 mg, which is often given as four 40-mg pills. But regorafenib can cause symptoms like skin reactions, including dryness, peeling, and cracking; discoloration of the hands and feet; fatigue; high blood pressure; and diarrhea, among other side effects. In clinical trials, these side effects have led to dose interruptions in nearly 40% of patients and dose modifications in around 25% of patients.

We often manage these side effects in a real-world clinic setting as well. In this study, we wanted to evaluate the feasibility and usability of this patient engagement tool in patients starting regorafenib in the outpatient setting.

What were the major findings from your study? Did any of the outcomes surprise you?

This was a feasibility study which included a small number of patients. Eleven patients were enrolled, but we ultimately analyzed data for 10 patients because one dropped out shortly after enrollment due to drug toxicity. The time of study ranged from 1 month to 5 months per patient. On average, patients completed the daily questionnaire and recorded their blood pressure 10 days (range: 2 to 20) out of a 30-day period. Providers were alerted to a trigger an average of 2 times per patient (range: 1 to 5), and 100% of triggers were addressed and resolved by the provider with the triage tool.

At the end of the study, 25% of patients were on the target daily dose of regorafenib at 160 mg daily. The majority (50%) were on one dose level down at 120 mg, and 25% were on an even lower daily dose of 80 mg.

Across the study, 62.5% of patients received the highest dose at some point in their treatment. The average dose increase per patient from start to end of the study was 1.25 regorafenib pills.

Overall, the application was usable by both providers and patients based on usage statistics and qualitative surveys.

How can these findings inform real-world clinical practice?

Since this was a feasibility study, these findings do not yet change real-world practice, but we have learned this digital tool is usable and acceptable from both patient and provider standpoints.

It could be useful to evaluate these tools in larger studies with more patients to see if an intervention like this can improve endpoints like quality of life, patient experience, toxicity management, or even compliance to drug dosing and titration. Larger studies could also show whether using a tool like this could impact survival, with increased patient compliance and decreased toxicity from drugs. I think we will see more studies interfacing clinical care and technology. Feasibility studies like ours somewhat lay the groundwork for these larger studies looking at oncologic and patient outcomes.

Is there anything else you would like to add?

With widespread smartphone and internet usage, it will be interesting to see if applications like the CarePrompter or others that patients can use on the go or at home will facilitate their cancer management. At the same time, we must recognize not all patients have the same resources or access to smartphones or internet, but this would be valuable to consider in future study designs.

Integrating tools like this to monitor patients is promising and has the potential to be applied across multiple disease subtypes and therapeutics. With more research, we may see the potential for these tools to improve patient experiences.

About Dr Mukherji

Reetu Mukherji, MD, is a gastrointestinal medical oncologist and assistant professor at Georgetown University. She practices at Georgetown University Medical Center in the Lombardi Comprehensive Cancer Center.

Dr Mukherji participated in this interview on behalf of John Marshall, MD, also affiliated with the Lombardi Comprehensive Cancer Center in Georgetown; Howard Isenstein and Amani Boudriga from Digidence, who developed the CarePrompter app; and Bayer, who funded the study.