Amgen Lung-Cancer Drug That Targets Mutation Cleared in U.S.

(Bloomberg) -- Amgen Inc.’s lung-cancer treatment sotorasib won approval from U.S. regulators, becoming the first therapy to target a tumor-stoking genetic mutation scientists have tried to block for decades.

The Food and Drug Administration clearance, while only for a small group of patients, is a milestone for oncology. The drug is the first to directly target a mutant gene called KRAS G12C that’s present in about 13% of non-small-cell lung cancers.

KRAS is a growth-promoting gene that’s mutated in numerous lung, colon and pancreatic tumors. The mutations cause a key protein to send constant signals for cells to grow and proliferate.

For some four decades, pharmaceutical companies have sought ways to block KRAS. So many efforts have failed or gone nowhere that it was sometimes considered impossible to thwart the mutation with a drug.

Amgen’s therapy targets one of several KRAS mutations and is unlikely to be the last of its kind approved. Numerous other companies, including Mirati Therapeutics Inc., are working on KRAS inhibitors.

“It’s been a 40-year quest,” David Reese, Amgen’s research head, said in an interview before the approval. “It is one of the first examples of drugging what has been considered to be an undruggable target.”

The shares rose 1.4% at 1 p.m. in New York. They had gained 2.3% this year through Thursday.

Data released by Amgen in January showed the therapy shrank tumors in 37% of advanced lung-cancer patients who hadn’t responded to chemotherapy and other treatments. Sotorasib, which will be sold under the brand name Lumakras, also prevented malignancies from progressing for a median of 6.8 months.

The treatment will cost $17,900 a month, in line with other targeted lung-cancer therapies, Amgen executives said in an interview before the approval. Patients will need a genetic test to confirm that their tumor contains the KRAS mutation before being treated.

The drug could generate $864 million in annual sales by 2025, according to an estimate from Bloomberg Intelligence. Wall Street analysts surveyed by Bloomberg expect $818 million.

Common side effects included diarrhea, musculoskeletal pain, nausea, fatigue, liver damage and cough, the FDA said in a statement. The agency’s analysis found the response rate to the drug was 36%. The drug was approved for advanced lung-cancer patients whose tumors have the mutation and who have failed at least one prior systemic therapy, the FDA said in a statement.

“KRAS mutations have long been considered resistant to drug therapy,” said Richard Pazdur, director of the FDA’s Oncology Center of Excellence. “Today’s approval represents a significant step towards a future where more patients will have a personalized treatment approach.”

Dosing Study

After the data was released in January, the FDA granted sotorasib priority review status, meaning the agency looks to make a decision within six months. The standard review time is about 10 months.

In April, Amgen said an agreement had been reached with the FDA to conduct a post-marketing study comparing the standard once-daily 960 milligram dose to a daily 240 milligrams. Amgen is exploring the lower dose to see whether the current regimen of eight pills a day can be cut, while maintaining effectiveness, Reese said. Results are expected in late 2022.

In addition to lung cancer, Amgen is testing sotorasib in colon-cancer patients.

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