FDA Approves Amgen Drug for Resistant Lung Cancer

The Food and Drug Administration (FDA) has granted accelerated approval to Amgen's dual-acting drug, Imdelltra, designed to treat small cell lung cancer patients whose disease has continued to progress following chemotherapy. Imdelltra, a form of immunotherapy, aids T cells in targeting tumor cells by binding to specific protein markers on their surface. This drug is notable for being the first bispecific antibody approved for small cell lung cancer and the tenth such drug approved for cancer in general.

The FDA's decision came more than three weeks ahead of the scheduled deadline, based on clinical trial data showing that Imdelltra was able to shrink tumors in 40% of the patients treated. However, Amgen is required to conduct a further study to validate Imdelltra’s benefits compared to other available treatments, which will determine its exact place in the market.

Small cell lung cancer accounts for approximately 14% of all lung cancer cases but has historically received less research focus compared to non-small cell lung cancer. Until the advent of newer treatments, chemotherapy was the predominant treatment option, although it offered a poor survival prognosis. The landscape of small cell lung cancer treatment began to change with the approval of immunotherapies like Roche’s Tecentriq and AstraZeneca’s Imfinzi in 2019 and 2020, respectively. These drugs are now used in combination with chemotherapy for newly diagnosed patients with extensive-stage disease, where cancer has spread beyond its original site.

Amgen’s bispecific antibody, targeting the delta-like ligand 3 protein, follows a similar path as previous efforts, such as AbbVie's antibody-drug conjugate rovalpituzumab tesirine, which failed in clinical trials. The bispecific approach has seen success in other cancer types, particularly blood cancers. For instance, Johnson & Johnson’s Tecvayli has shown efficacy in treating multiple myeloma. Imdelltra operates by engaging the CD3 protein on T cells, a common target for these types of therapies.

Known scientifically as tarlatamab, Imdelltra is specifically for patients whose disease progresses after undergoing chemotherapy. Typically, patients on chemotherapy alone have an average survival span of 10 months. The addition of Imfinzi to chemotherapy has extended survival by three months, and Tecentriq by two months, based on clinical trial results.

However, Imdelltra is associated with significant immune-related side effects, notably cytokine release syndrome. This serious reaction was mostly observed after the initial doses during testing. Accordingly, the FDA label advises patients to remain close to a medical facility for monitoring after the first doses and recommends that doctors interrupt or discontinue treatment in severe cases.

William Blair analyst Matthew Phipps has highlighted the approval of Imdelltra as a substantial improvement over existing treatment options. Given the lack of an approved standard of care for patients in this specific condition, Phipps predicts that Imdelltra could achieve sales of $842 million by 2028. The pricing for Imdelltra is set at $31,500 for the first treatment cycle and $30,000 for subsequent cycles, reflecting the drug’s anticipated impact on the market based on disease prevalence and other economic factors.