Targeted Drug Erdafitinib Benefits Some Patients with Advanced Bladder Cancer

In April, the drug erdafitinib (Balversa) became the first therapy targeting a genetic alteration to be approved by the Food and Drug Administration (FDA) of US to treat patients with metastatic urothelial carcinoma, the most common type of bladder cancer.

FDA granted
an accelerated approval to the drug, which blocks the activity of a family of
proteins called fibroblast growth factor receptors (FGFR), for patients with
specific FGFR gene alterations, based on preliminary data from a clinical

New findings
from that trial have just been published. The updated results confirm that
erdafitinib can benefit patients with advanced bladder cancer whose tumors have
a genetic alteration in one of the four FGFR genes, according to Arlene
Siefker-Radtke, M.D., of the University of Texas MD Anderson Cancer Center, who
led the trial.

In the
study, erdafitinib decreased the tumors of some patients whose cancers did not
respond to other treatments, the researchers reported in the New England
Journal of Medicine on July 25.

approval covers patients whose cancer has spread outside of the bladder locally
or to other parts of the body during or after treatment with standard

“Our patients with metastatic bladder
cancer have very limited treatment options, and this represents a real unmet
need,” Dr. Siefker-Radtke said. 

“Now that erdafitinib has been
approved by the FDA, doctors can incorporate the drug into treatment strategies
to benefit patients with FGFR-altered urothelial cancer,” she continued.
“Additional research is ongoing to learn how to combine erdafitinib with
immunotherapy drugs such as immune checkpoint inhibitors.”

FDA has
approved several checkpoint inhibitors for advanced bladder cancer, but only
approximately 20% of patients benefit from these
treatments, Dr. Siefker-Radtke noted.

comparison, 40% of the patients in the international
phase 2 trial that led to the approval
responded to erdafitinib, Dr. Siefker-Radtke and her colleagues reported.

To confirm
the study’s results, a phase 3 clinical
trial is comparing erdafitinib with standard chemotherapy and with the
checkpoint inhibitor pembrolizumab (Keytruda) in patients with advanced bladder
cancer whose tumors have an FGFR alteration.

Trial Results

20% of patients with metastatic urothelial cancer of the
bladder and 35% of patients with metastatic
urothelial cancer of the renal pelvis and ureter have an alteration in an FGFR
gene. When FDA approved erdafitinib, which is given as a pill, the agency also approved
a companion diagnostic test that doctors can use to help identify patients
whose tumors carry one of these FGFR alterations.

Of the 99 patients in the trial, 87 had been treated previously with chemotherapy, and 43% had received at least two prior courses of treatment.
Nearly 80% had metastases beyond nearby lymph

“Overall, this group of patients
typically has poor outcomes,” said Dr. Siefker-Radtke.

For this
reason, a 40% response rate is “really
remarkable,” noted Andrea Apolo, M.D., of NCI’s Center for Cancer Research, who
was not involved in the trial.

“Erdafitinib is an important new drug
for some of our patients with bladder cancer,” she added.

In the
trial, the median amount of time before the disease progressed
(progression-free survival) was 5.5 months,
and the median overall survival was 13.8

The most
common treatment-related side effects included inflammation or irritation of the
mucous membranes in the mouth, changes to nails, and hand–foot syndrome.

can also cause eye disorders
that can lead to changes in the visual field, although these
can be managed, according to Dr. Siefker-Radtke. 

In the
trial, 46% of patients experienced side effects
that were largely managed by adjusting the dose of therapy. Thirteen percent of
the patients discontinued treatment because of side effects.

Research & Development, which developed erdafitinib in collaboration with Astex
Pharmaceuticals, sponsored the trial.

Responses to Treatment

For some
patients in the trial, tumors started responding to erdafitinib soon after
their treatments began, Dr. Siefker-Radtke noted. 

“I was surprised by how quickly some
patients with rapidly progressing disease responded to the drug,” she said.
“Within a week or two of starting treatment, the health of some of these
patients improved significantly.”

For one
group of patients—those whose cancers did not respond to immunotherapy drugs—the
response rate was 59%, suggesting to the researchers that
these patients, in particular, might benefit from erdafitinib.  

In previous
bladder cancer clinical trials, Dr. Siefker-Radtke had noticed that patients
with FGFR mutations
were less likely to respond to checkpoint inhibitors
than patients who lacked the mutations.

erdafitinib became available, she and her colleagues developed the phase 2 trial. But the current results are not definitive, Dr.
Siefker-Radtke cautioned.

The phase 3 trial, she added, will provide more information about
“whether patients with FGFR-altered urothelial cancer benefit more from
erdafitinib or a checkpoint inhibitor.”

Targeted Drug Erdafitinib Benefits Some Patients with Advanced Bladder Cancer was originally published by the National Cancer Institute (US).”

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