Pfizer’s Lung Cancer Drug Is Extending Survival Rates and Stopping Cancer Spread

Responsible for one in eight cancers worldwide, lung cancer is the most frequently diagnosed cancer. Despite the available treatment options of surgery, chemotherapy, radiation therapy, and immunotherapy drugs, survival rates among patients with advanced stages of lung cancer have been bleak.

However, Pfizer’s lung cancer drug is showing promising results. New clinical trial results show that Lorbrena (lorlatinib) stops lung cancer from advancing in patients with ALK-positive non-small cell lung cancer (NSCLC), a type of lung cancer that occurs when the ALK gene mutates and causes abnormal lung cell growth.

The Best Survival Rates Yet

Among 296 patients with ALK-positive lung cancer participating in Pfizer’s CROWN trial, Lorbrena demonstrated a 94% reduction in the risk of developing intracranial progression—the stage where tumors begin forming in the brain. This resulted in the longest progression-free survival results ever recorded in patients with NSCLC.

“After a five-year follow-up, we’ve not hit a median progression-free survival, which means it’s still 60% of the patients who are on [Lorbrena] continue to be on it,” study coauthor Todd Bauer, MDmedical oncologist with Tennessee Oncology in Nashville, told Verywell.

This is a “good problem to have,” as patients are continuing to benefit from the treatment, Bauer said.

Lorbrena is the only ALK tyrosine kinase inhibitor (TKI) to have reported five-year progression-free survival. As cancer drugs, ALK TKIs work by stopping proteins that cause tumor cells to grow abnormally. Other inhibitors, like Xalkori (crizotinib), have been effective for the first 12 months, but drug resistance and cancer mutations mean cancer typically progresses after that.

Most Common Side Effects Are Manageable

Bauer said the two most common side effects of Lorbrena are hypercholesterolemia, which is high levels of cholesterol in the blood, and hypertriglyceridemia, which is elevated levels of triglycerides in the blood. Both can be managed using statins and fibrates.

Other common side effects of Lorbrena include but are not limited to:

• Swelling in the arms, legs, hands, and feet (edema)
• Numbness
• Weight gain
• Problems with thinking, such as forgetfulness or confusion
• Fatigue
• Breathing difficulty
• Joint pain
• Diarrhea
• Mood changes
• Cough

“To manage, we have to try lifestyle modifications, so compression stockings and raising your legs,” Bauer said.

In clinical practice, side effects can also be managed with a dose reduction or by pausing the drug.

“The standard dose of Lorbrena is a 100 milligram tablet once a day. And if patients start to have those [side effects]you can introduce them to 75 milligrams once a day, or all the way down to 50 milligrams once a day,” Bauer said.

According to the CROWN trial data, dosage changes don’t compromise efficacy. Patients who had a dose reduction within the first 16 weeks of starting saw no difference in median progression-free survival or intracranial response rates.

“Even at that slightly lower dose, you still maintain the full efficacy of the drug,” Bauer said.

Lorbrena’s Protects Against Brain Cancer, Too

Brain metastases, which occur in about 25% of lung cancer patients at diagnosis, generally lead to a poor prognosis. However, the CROWN study showed that Lorbrena was effective at preventing brain metastases. After five years, 92% of patients on Lorbrena hadn’t developed brain cancer, compared to 21% of patients on Xalkori.

For patients with existing brain metastases, 81% of those on Lorbrena hadn’t developed more brain cancer while taking Lorbrena, whereas all patients on Xalkori either saw their cancer progress or dropped out of the study within two years.

Lorbrena was also effective in patients without brain metastases. Only 4 of 114 patients developed brain lesions in the first 16 months of treatment.

Who’s a Good Candidate for Lorbrena?

Lorbrena is currently approved in the U.S. for adults with NSCLC whose tumors are ALK-positive, as detected using an FDA-approved test of a tissue sample. Bauer said that there are other predictors of response, such as looking at whether there’s a commutation in the TP53 gene.

ALK positive NSCLC is an aggressive cancer, but it’s important to note that not all NSCLCs are ALK-positive. In fact, only 5% of NSCLC cases are ALK-positive.

Since Lorbrena is an ALK inhibitor, it may not be an effective form of treatment for NSCLC patients who do not have the ALK mutation or other forms of lung cancers. Lung cancer patients should talk to their oncologist about ALK testing.