What exactly is chemotherapy-induced nausea and vomiting (CINV) and why is it important to prevent?

Chemotherapy-induced nausea and vomiting, or CINV, is a very common side effect for cancer patients undergoing chemotherapy. It can significantly decrease their quality of life and make it harder for them to stick to their treatment plan. Preventing CINV is a really important part of cancer care to ensure patients can tolerate and benefit from their therapy.

What is rolapitant (Varubi®), and how does the new intravenous (IV) version change the game for CINV prevention?

Rolapitant, also known as Varubi, is a medication called a neurokinin-1 (NK-1) receptor antagonist. It's specifically designed to prevent delayed CINV, which is nausea and vomiting that starts more than 24 hours after chemotherapy. Previously, rolapitant was only available as an oral medication. Now, an intravenous (IV) version offers another option, especially useful for patients who can't swallow or absorb oral medications properly.

What does it mean that intravenous and oral rolapitant are bioequivalent, according to this research?

The study showed that intravenous rolapitant and oral rolapitant are bioequivalent. Bioequivalence means that both forms of the medication deliver the same amount of the drug to the body and have similar effects. The study confirmed that the clinical benefits seen with oral rolapitant can also be achieved with the IV formulation, giving patients and healthcare providers another effective option to prevent CINV.

How was the study designed to compare intravenous and oral rolapitant, and what key measurements were used?

The study compared a single IV infusion of 166.5 mg of rolapitant to a single oral dose of 180 mg in healthy volunteers. Researchers collected blood samples over 912 hours to measure rolapitant levels in the body. They looked at how the drug was absorbed and eliminated to determine if the IV formulation was bioequivalent to the oral one. They measured AUC0-t and AUC0-∞, systemic exposure, and tolerability to ensure that the IV version performed similarly to the oral version.

What are the broader implications of having an intravenous rolapitant option, and what future research could build on these findings?

The introduction of intravenous rolapitant offers a significant advantage for patients who have difficulty taking oral medications due to nausea, vomiting, or other complications. While this study focused on bioequivalence, future research could explore specific patient populations who might benefit most from the IV formulation. Additionally, studies comparing rolapitant to other antiemetic drugs could further refine CINV prevention strategies.

Intravenous chemotherapy treatment visualized with a calming blue drip.

IV vs. Oral Rolapitant: Which is the Best Option for Chemotherapy-Induced Nausea?

Avery Sinclair in Health & Wellness December 2025 • 4 min read.

"A new study reveals the bioequivalence of intravenous and oral rolapitant, offering more options for CINV prevention."

Chemotherapy-induced nausea and vomiting (CINV) is a common and debilitating side effect of cancer treatment, significantly impacting a patient's quality of life and their ability to adhere to treatment plans. Effective prevention of CINV is therefore a critical aspect of cancer care. While several antiemetic drugs are available, finding the optimal route of administration and ensuring consistent efficacy remains a challenge.

Rolapitant (Varubi®) is a neurokinin-1 (NK-1) receptor antagonist approved for preventing delayed CINV. The original formulation was an oral medication, but now an intravenous (IV) version is being explored to offer more flexibility in treatment. This is particularly helpful for patients who have difficulty swallowing or absorbing oral medications.

A pivotal study was conducted to determine if the IV formulation of rolapitant is bioequivalent to the oral formulation. Bioequivalence means that both formulations deliver the same amount of drug to the body and have similar effects. The study's goal was to assess whether the clinical benefits of oral rolapitant could be extended to the IV formulation, offering another option for patients at risk of CINV.

Rolapitant Study: IV and Oral are Equally Effective

Intravenous chemotherapy treatment visualized with a calming blue drip.

The study, a randomized, open-label phase I trial, compared a single intravenous infusion of rolapitant (166.5 mg) to a single oral dose (180 mg) in healthy volunteers. Blood samples were collected over 912 hours to measure rolapitant concentrations and assess how the drug was absorbed and eliminated from the body.

The key finding was that the IV infusion of rolapitant met the criteria for bioequivalence when compared to the oral dose. This means that both formulations result in similar overall exposure to the drug in the body.

AUC0-t and AUC0-∞: The 90% confidence intervals (CIs) for the ratios of geometric least-squares means (GLSMs) for the area under the plasma concentration-time curve (AUC) from time 0 to the time of the last quantifiable concentration (AUC0-t) and AUC from time 0 extrapolated to infinity (AUC0-∞) were within the 0.80-1.25 range, indicating bioequivalence.
Systemic Exposure: Mean rolapitant systemic exposure and half-lives were similar in both the oral and intravenous groups.
Tolerability: The incidence of treatment-emergent adverse events (TEAEs) was similar in the intravenous and oral groups, and all were mild or moderate in severity.

The study also found that while the peak concentration (Cmax) was higher and the time to reach peak concentration (Tmax) was shorter with the IV formulation, the overall systemic exposure (AUC) was comparable. This suggests that the IV route allows for faster absorption but doesn't change the total amount of drug the body receives.

Intravenous Rolapitant: A Game Changer for CINV Prevention?

This bioequivalence study supports the use of intravenous rolapitant as an alternative to the oral formulation for preventing CINV. This is particularly important for patients who cannot tolerate oral medications due to nausea, vomiting, or other complications.

The availability of both oral and IV rolapitant allows healthcare providers to tailor treatment plans to individual patient needs, potentially improving compliance and overall CINV control. Furthermore, because rolapitant is not an inhibitor or inducer of CYP3A4, dose adjustments of concomitant dexamethasone are not required, offering a simpler approach to CINV management.

Ultimately, the findings suggest that IV rolapitant could be a valuable addition to the antiemetic toolkit, offering an effective and well-tolerated option for preventing delayed CINV in patients undergoing chemotherapy. Further studies may explore the benefits of IV rolapitant in specific patient populations or clinical settings.