EGFR+ lung cancer is a form of lung cancer not associated with smoking, caused by nonhereditary gene mutations. One of these mutations, known as exon 20, had limited treatment options until the introduction of Mobocertinib in 2021. However, the drug was withdrawn from the U.S. market by the manufacturer, and the UK plans to follow suit. This has raised concerns among EGFR+ campaigners, as those with this mutation may have limited treatment options after chemotherapy. This type of lung cancer affects younger individuals and presents with atypical symptoms, such as musculoskeletal pain, rather than the typical symptoms of smoking-related lung cancer.
EGFR+ lung cancer is primarily caused by mutations of the epidermal growth factor receptor, such as EGFR 19 deletion and EGFR L858R point mutation. The exon 20 insertion mutation is the third most common cause, accounting for up to 10% of cases. People with this mutation generally have a poorer prognosis compared to other mutations. Mobocertinib, a tyrosine kinase inhibitor, was designed specifically to target this uncommon mutation and received approval for use in the U.K. in 2021. However, the drug was recently withdrawn from the U.S. market due to lack of significant impact on progression-free survival in clinical trials.
The withdrawal of Mobocertinib has raised concerns among EGFR+ patients and campaigners, as it leaves a significant treatment gap for those with the exon 20 mutation. Dr. Gini Harrison, a psychologist and research trustee at EGFR+ UK, emphasized the impact of removing the drug from the market, stating that it would reduce lifespans and increase mortality rates among affected patients. While the drug was well tolerated and showed promise in early trials, it failed to meet its primary endpoint in phase 3 clinical trials, leading to its withdrawal by the manufacturer.
Despite the withdrawal of Mobocertinib, patients already on the medication can access it through a compassionate use program if they are benefiting from the treatment. However, there are limited alternatives for new patients with the exon 20 mutation, as Mobocertinib was the only NHS-funded treatment in the U.K. Another drug, aminvantamab, has shown potential for exon 20 patients but is only available privately, making it inaccessible to many patients without private insurance. Dr. Harrison called for expedited NICE approval processes to make aminvantamab available to NHS patients facing a treatment gap.
The decision to withdraw Mobocertinib was based on its failure to meet primary endpoints in clinical trials, rather than safety concerns. Health authorities are now faced with the challenge of providing alternative treatment options for EGFR+ patients with the exon 20 mutation. Dr. Harrison highlighted the necessity of making effective treatments like aminvantamab accessible to NHS patients to address the unmet need in this patient population. Overall, the withdrawal of Mobocertinib has underscored the importance of ensuring access to effective treatments for individuals with rare mutations of EGFR+ lung cancer.
