A Bayer drug designed to attack tumors caused by a rare genetic mutation has now accelerated FDA approval, providing another treatment option for certain patients with advanced cases of lung cancer.
Wednesday’s regulatory decision for Bayer’s drug sevabertinib covers the treatment of adults whose locally advanced or metastatic non-squamous non-small cell lung cancer (NSCLC) has tumors with HER2 (also called ERBB2) mutations. In addition to carrying this mutation, patients eligible to receive Bayer’s drug must have cancer that has progressed after at least one prior line of systemic therapy. In addition to approving the drug, which will be branded Hyrnuo, the FDA also approved a companion diagnostic from Life Technologies to identify patients who may be eligible for treatment with Bayer’s twice-daily pill.
HER2, a cell surface receptor, helps regulate normal cell growth. Mutations in HER2 can cause cancer. These mutations are rare and are found in approximately 2% to 4% of NSCLC cases. Hyrnuo is an oral small molecule inhibitor of mutated HER2.
Bayer evaluated Hyrnuo in a single-arm, open-label Phase 1/2 study in patients who had received prior therapy. In the 70 patients who had never received therapy targeting HER2 mutations, the results showed an objective response rate of 71%. The median duration of response was 9.2 months; Of those who responded to treatment, 54% showed a duration of response of six months or more.
In 52 participants who had received prior systemic therapy, including a HER2-targeting antibody drug conjugate such as AstraZeneca and Daiichi Sankyo’s Enhertu drug, Bayer’s drug produced an objective response rate of 38%. The median duration of response was 7.0 months; 60% of patients who responded to treatment had a duration of response of six months or more. Detailed results were published last month in the New England Journal of Medicine.
While patients with advanced cases of NSCLC have had the option of treatment with Enhertu, this medication carries the risk of interstitial lung disease. Bayer’s drug does not avoid that risk. The FDA notes that interstitial lung disease is among the possible risks of complications associated with Hyrnuo. Other side effects reported in the clinical trial include diarrhea, liver toxicity, eye toxicity, and elevated pancreatic enzymes.
The FDA’s decision for Hyrnuo is an accelerated approval based on Phase 1/2 data. Bayer may need to provide additional clinical data to confirm the safety and effectiveness of the product.
The approval of Hyrnuo follows the accelerated approval in August of Boehringer Ingelheim’s zongertinib, brand Hernexeos, an oral HER2-targeting drug that was also developed for advanced cases of NSCLC. While both drugs are approved for the same indication, Boehringer’s drug has the advantage of being administered once a day.
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