The FDA’s Real Time Oncology Review (RTOR) pilot has inaugurated yet another new med. This time, the victory goes to a pair of Otsuka subsidiaries in a rare form of bile duct cancer.
Late last week, Otsuka’s Taiho Oncology and Taiho Pharmaceutical nabbed approval for their drug futibatinib in adults with previously treated, unresectable, locally advanced or metastatic cholangiocarcinoma in the liver with fibroblast growth factor receptor 2 (FGFR2) gene fusions or other rearrangements.
Taiho’s drug—an FGFR inhibitor now christened Lytgobi—is wading into an increasingly crowded bile cancer arena where Incyte’s Pemazyre (pemigatinib) and BridgeBio and QED Therapeutics’ Truseltiq (infigratinib) are already duking it out.
Lytgobi nabbed an accelerated approval thanks to its reported overall response rate and response duration in the clinic, Taiho pointed out in a release. To keep hold of the green light, the company says it may have to further validate the med’s benefit in confirmatory trials.
The FDA blessed Taiho’s drug on data from the phase 2 FOENIX-CCA2 study, which enrolled 103 bile duct cancer patients harboring FGFR2 gene rearrangements, including fusions, as determined by next-gen sequence testing. Patients in the study received 20 mg futibatinib tablets by mouth daily until disease progression or unacceptable toxicity.
In the study, Lytgobi yielded an objective response rate of 42%, meeting the trial's primary endpoint. Additionally, Taiho’s drug charted a 9.7-month median duration of response. Among patients who responded, 72% of responses lasted at least six months, the companies added.
Aside from milder Lytgobi side effects like nail toxicity, muscle and skeletal pain, constipation, diarrhea, fatigue, dry mouth and vomiting, the med comes with a warning for eye toxicity and hyperphosphatemia, which can cause soft tissue mineralization, plus formation of calcium deposits in soft tissue, skin ulcers and mineral deposits along the walls of the arteries and veins.
On the whole, cholangiocarcinoma is an aggressive cancer of the bile ducts diagnosed in some 8,000 people each year in the U.S., Taiho notes. That disease population includes those with both intrahepatic and extrahepatic disease, which refers to disease inside and outside of the liver, respectively. Around 20% of patients diagnosed with the cancer suffer from the intrahepatic form, which is covered by Lytgobi’s indication.
Further breaking down the opportunity in store for Lytgobi, Taiho explained that within the 20% of patients with intrahepatic CCA, 10% to 16% have FGFR2 gene rearrangements, including fusions, which “promote tumor proliferation.”
But Lytgobi isn’t the only FGFR inhibitor in town. Incyte’s classmate Pemazyre first entered the fray in 2020, bagging an approval in April of that year to treat bile duct cancers with an FGFR2 fusion or other rearrangement.
A little more than a year after that, BridgeBio and its affiliate QED Therapeutics won an FDA nod for their med Truseltiq, which is also cleared in previously treated, locally advanced or metastatic bile duct cancer with an FGFR2 fusion or rearrangement.
At the time of Truseltiq’s approval last year, Mizuho securities analysts noted the BridgeBio med’s lower price tag could give it an edge over Pemazyre, especially during the first month of treatment.
Pemazyre rolled out with a list price of $17,000 per treatment cycle. At an average treatment duration of around six months and eight or nine cycles, the cost per patient would land somewhere between $136,000 and $153,000. The drug generated $68.5 million in 2021 sales.
BridgeBio, for its part, aimed to launch Truseltiq at a price of about $21,500, the Mizuho analysts said at the time. Under that assumption, the drug would cost around $64,500 every month, marking a roughly 5% lower price than Pemazyre over the same period.
In Lytgobi’s case, it isn’t immediately clear how Taiho plans to price its drug.
Fierce Pharma has reached out to Taiho Oncology for comment on price and launch plans, but the company did not immediately respond.