Astra’s Immune Drug First to Check Mid-Stage Lung Cancer Growth

  • Trial results “opens a door that’s very big,” CEO Soriot says
  • Study gives Imfinzi an edge over drugs from Merck, Roche

Lung cancer on the left pulmonary lobe.

Source: BSIP/UIG Via Getty Images

AstraZeneca Plc’s Imfinzi stalled the progress of mid-stage lung cancers in a trial, offering patients a potential new therapy for the deadly condition and boosting the U.K. company’s prospects in the race to develop breakthrough treatments.

Patients who received Imfinzi after radiation and chemotherapy saw growth of their tumors pause about three times as long as those who took a placebo after the standard treatments, according to study results that will be presented on Saturday at the ESMO 2017 Congress in Madrid. The clinical trial dubbed Pacific is the first to look at using immunotherapies, or drugs that harness the body’s own defense system, in earlier stage lung cancers that can’t be removed surgically. 

The results give the Cambridge, England-based company an edge over key rivals including Merck & Co., Roche Holding AG and Bristol-Myers Squibb Co. in providing a treatment to patients whose cancer hasn’t spread widely. It also reinforces Astra Chief Executive Officer Pascal Soriot’s confidence in the drug that’s poised to become the company’s best-selling medicine but failed a key test for halting tumors in sicker patients in July, sending the shares into a tailspin.

Opens Door

“The Pacific data is opening a door that’s very big,” Soriot said in an interview in London. “We are looking at additional studies to expand in this early phase, which is where the majority of the patients are and also where you can save lives.”

Imfinzi, which is already approved in treating bladder cancer, could generate about $8.14 billion annually by 2023 when used by itself or in combination with another immunotherapy, according to the average of analysts’ estimates compiled by Bloomberg. Sales of the drug for treating stage 3 lung cancer patients alone could reach as much as $1.7 billion, analysts at Jefferies Group LLC estimate.

Astra is in discussions with regulators in advance of seeking approval for using the treatment for lung cancer, the world’s most common and deadly tumor. The U.S. Food and Drug Administration granted Imfinzi breakthrough status last month for certain stage 3 cancers, making it eligible for priority review and a faster decision.

“In the early stage, we’re first and alone for a couple of years,” Soriot said.

About one-third of patients with non-small cell lung cancer, the most common form of the disease, are diagnosed in stage 3.

Imfinzi is likely to become standard treatment for these patients, who almost always relapse after the first round of treatment, said Stefan Zimmerman, head of outpatient immune oncology at Lausanne University Hospital in Switzerland.

Stalling Growth

“It’s really an area where we need progress,” he said. “It doesn’t make sense to wait for progression or relapse to give them a late sequential immunotherapy.”

The median time for cancers to resume growing was 16.8 months for patients taking Imfinzi, compared with 5.6 months among patients receiving placebo. The results were also published online by the New England Journal of Medicine.

Rates of severe adverse events were similar in both groups, with pneumonia being the most common. 

Testing Imfinzi in stage 3 cancers gave the company an opportunity to be first and do something different than competitors testing drugs in later-stage, metastatic cancers that have spread extensively, Soriot said. Earlier-stage patients may respond better to immune therapies because their bodies’ own defenses remain strong and can be better activated by drugs, according to the CEO.

Potential for Cures

“In metastatic, you extend lives, you keep patients alive -- you don’t cure them,” he said. “In the early stage, you can potentially cure them.”

In a separate study, Astra’s Tagrisso outperformed the company’s older Iressa drug and a Roche medicine called Tarceva in halting the growth of tumors for patients with advanced lung cancers and an abnormal, tumor-spurring protein called EGFR. The other two medicines, which are typically used to treat such patients, block the protein’s activity, but often stop working over time because of mutations in the gene that makes EGFR. 

Tagrisso, a pill that’s already approved in treating some forms of lung cancer, blocks a gene mutation that causes drug resistance. Sales of the therapy may climb to $3.75 billion by 2023, according to estimates compiled by Bloomberg. It’s likely to face competition from Pfizer Inc.’s experimental treatment dacomitinib.

Asian patients are more likely to have EGFR-driven lung tumors, and almost two-thirds of the patients in the study were Asian. Patients who received Tagrisso went 18.9 months before their cancers started growing again, compared with 10.2 months to cancer growth among the patients getting Iressa or Tarceva. In a trial reported earlier this year, Pfizer’s treatment slowed the growth of tumors by 14.7 months, compared to 9.2 months for Iressa.

Researchers pointed out that, unlike many other drugs, Astra’s therapy also enters the brain, where it can fight cancers that often spread there from the lung.

“There’s no competition there now,” Lausanne University Hospital’s Zimmerman said. “When you almost double the duration of response for all patients, so for the whole population, then this is really compelling.”

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