The Food and Drug Administration approved Mirati Therapeutics' rival to Amgen's lung cancer drug, sending MRTX stock higher on Tuesday.
In premarket trading on today's stock market, MRTX stock popped 5.1% near 43.50. Amgen stock also advanced 2.9% near 284.90.
The drug now dubbed Krazati is the second to hit the market that blocks a specific mutation in a protein called KRAS. For decades, researchers knew the protein had ties to cancer but, based on its bowling-ball-like shape, couldn't figure out how to give an antibody a toehold on it. Without that ability, they couldn't stop the cancer-driving protein from wreaking havoc.
Now, in the span of two years, the FDA has granted accelerated approval to two KRAS blockers.
"Forty years ago, KRAS was identified and now it's actually a druggable target and actionable, which is just great for the patients out there," Mirati Chief Executive David Meek told Investor's Business Daily. "Physicians actually have something else in their treatment armamentarium to treat these patients."
MRTX Stock: Rivaling Amgen's Lumakras
The FDA granted Krazati accelerated approval, meaning it's contingent upon further testing. Mirati's drug can now treat patients with non small-cell lung cancer whose tumors have what's called the G12C mutation in the KRAS protein. Patients must have first received at least one prior treatment.
The approval is based on a midstage study that showed 43% of patients responded to treatment. Overall survival — a metric that examines how long patients lived before any cause of death — was 14.1 months.
In comparison, when Amgen's Lumakras was approved, the drug showed an overall response rate of 36%. Recently, Amgen said 28% of patients responded to Lumakras in a study pitting it against chemotherapy. Overall survival was 10.6 months.
"We have a 50% difference in response rates and a slightly longer overall survival," Mirati's Meek said. "That's compelling for physicians."
Bullishly for MRTX stock, Krazati has shown promise in treating patients whose cancer has spread to the brain. Meek estimates 40% of patients in this lung cancer population have brain metastases and an additional 20% go on to develop them.
Krazati's label doesn't note the potential to treat brain metastases. Meek says the company will have to run additional testing before requesting a label update from the FDA.
Mirati Shares Are On A Wild Ride
The approval comes at a wild time for MRTX stock.
Last month, shares surged on reports that a Big Pharma company could acquire Mirati. The list of potential buyers included Pfizer, Merck, Bristol Myers Squibb and AstraZeneca.
But earlier this month, shares crashed after Mirati unveiled the results of a study combining Krazati and Merck's blockbuster Keytruda in previously untreated lung cancer patients. The regimen appeared safe — a key point for combination approaches — but analysts questioned whether it could outperform standard chemotherapy added to Keytruda.
Overall, 49% of patients responded, compared with 48% for Keytruda plus chemo, SVB Securities analyst Andrew Berens said in a report.
"Ultimately, we think the data will continue to fuel speculation on whether (Krazati) can successfully achieve a place in the (previously untreated) treatment paradigm commercially," he said.
MRTX stock plummeted over three days, losing more than half its value.
Follow Allison Gatlin on Twitter at @IBD_AGatlin.
