Eur Urol Oncol: What is the real-world practice model and safety of radiotherapy and cabozantinib in combination for metastatic renal cell carcinoma?

Currently, there are very few
data on the safety of cabozantinib in combination with radiotherapy.

Recently, researchers from Canada published an article in Eur Urol Oncol investigating the practice model, safety and efficacy of cabozantinib combined with radiotherapy for the treatment of metastatic renal cell carcinoma (mRCC).

The researchers conducted an international multicenter retrospective study of mRCC patients who received cabozantinib treatment from 2014 to 2020 who received radiation therapy
30 days before starting cabozantinib to 30 days after cabozantinib was discontinued.
The primary outcome was the rate
of grade ≥3 adverse events (AEs) occurring within 90 days of radiotherapy.
Secondary outcomes included hospitalisation rates and patterns
of use of cabozantinib and radiotherapy.
Baseline characteristics and AEs are descriptive results
.

A total of 127 consecutive patients
were included.
Most patients had clear cell histologic features (88%), had intermediate-risk disease as defined by the International Consortium for Metastatic Renal Cell Carcinoma Database (57%), and had received at least one frontline treatment (93%)
.
Of the 127 patients, 67 (53%) received cabozantinib at the same time as radiotherapy
.
Overall, grade 3 to 4 AEs occurred in 6.
3% (n=8/127) of patients, and no grade 5 events
were observed.
Among patients receiving conventional palliative radiotherapy (n=88), the incidence of grade 3-4 AEs in patients receiving cabozantinib and radiotherapy and patients not receiving cabozantinib and radiotherapy was 6.
3% (n=3/48) and 5.
0% (n=2/40),
respectively.
No patients were hospitalized
for radiotherapy-related toxicity.
After receiving stereotactic ablative radiotherapy (SABR; n=50), the rates of grade 3-4 AEs in patients who received cabozantinib and did not receive cabozantinib and radiotherapy were 3.
6% (n=1/28) and 9.
1% (n=2/22),
respectively.
One patient in the non-contemporaneous group was hospitalized with muscle weakness suspected to be associated with
angioedema associated with multiple brain metastases 19 days after SABR.

Toxicity levels at different treatment sites and regimens

In summary, in this real-world study of patients treated with mRCC with cabozantinib, 53% of patients received radiation therapy at the same time, and within 90 days of receiving radiotherapy, few reports of grade 3-4 AEs were reported
.
In addition, the use of radiotherapy and cabozantinib requires risk-benefit assessment of patient and disease characteristics to optimize treatment regimens
.

Original source:

Chun Loo Gan， Jiaming Huang， Elizabeth Pan et al.
Real-world Practice Patterns and Safety of Concurrent Radiotherapy and Cabozantinib in Metastatic Renal Cell Carcinoma： Results from the International Metastatic Renal Cell Carcinoma Database Consortium.
Eur Urol Oncol.
Nov 2022