As early as the 1990s, physicians treated cancer with immunotherapy drugs, which use the body’s own immune system to destroy cancer cells. Immunotherapies are evolving, offering hope for patients with hard-to-treat cancers. Within the past decade, researchers developed a new class of immunotherapy drugs called bispecific antibody T-cell engagers (BsAbs). While not available for all cancers, their use is expanding. The Froedtert & the Medical College of Wisconsin Cancer Network is one of only a few in Wisconsin that provides BsAb therapy. It was the first in the state to offer tarlatamab, a recently FDA-approved BsAb therapy for small cell lung cancer.
Q: How does bispecific antibody T-cell engager therapy work?
Dr. D’Souza: BsAb therapy is called “bispecific” because it identifies two different targets — a protein on cancer cells and a protein on T cells that are part of our immune system. Essentially, BsAbs connect T cells to tumor cells, triggering the immune system to eliminate cancer cells.
Q: How effective is BsAb therapy?
Dr. D’Souza: It can be effective for certain types of cancer. For example, BsAb therapies have produced good responses for most people with multiple myeloma, even when they have had multiple relapses. Additionally, in some clinical trials, these patients stay in remission for upwards of a year. BsAbs have produced good response rates as single treatments. We are learning how to combine them with other effective therapies to make response rates even better.
Q: What cancers can be treated with BsAb therapy?
Dr. D’Souza: BsAbs are FDA-approved to treat several challenging cancers: multiple myeloma, melanoma, lymphoma, leukemia and small cell lung cancer. The drug tarlatamab, for small cell lung cancer, has only been approved for a few months. Several more BsAb therapies are in the clinical research pipeline or available through clinical trials.
Q: Why is it important to receive BsAb therapy in an academic medical center with an experienced team?
Dr. D’Souza: Safe treatment with BsAb therapy requires intensive resources. A team experienced in delivering BsAbs, along with the right facilities and support resources, is essential for good patient outcomes. Patients who receive BsAb treatment need careful monitoring due to the potential for serious side effects. They must be educated about symptoms that could become serious, have access to the treatment team and be near emergency care. Often, we give these drugs during a hospital stay, starting with small doses before stepping up to higher doses. We do that for two to three doses. Only then, do we administer a full dose. If side effects occur, we immediately use drugs to counteract them. Our center is unique because we have the experience and ability to treat patients in our outpatient clinic. If there are no complications, they go home the same day, returning the following day. If they develop complications, we treat them in our 24-Hour Cancer Clinic.
Q: What does the future hold for BsAb therapy?
Dr. D’Souza: There are many exciting developments in BsAb therapies. In multiple myeloma, researchers are trialing newer antigen targets and new BsAbs. In other clinical trials, they are exploring if BsAbs can effectively treat people with earlier-stage cancers and how BsAbs may be combined with existing therapies. Finally, myeloma trials are evaluating if BsAbs can be stopped safely in select circumstances, especially if tests show there is no longer evidence of disease. This could provide patients with a much-needed treatment break.
