More Control, Better Quality Of Life: What To Know About Tarlatamab, The New Immunotherapy Drug Approved For Small-Cell Lung Cancer

Second-line treatment — therapy given after the cancer returns — was usually more chemotherapy. While it sometimes slowed the disease briefly, it often came with heavy side effects and only small improvements in survival.

“It was a very high tradeoff,” says Dr. Alahmadi. “Patients paid a lot in quality of life for very little gain.”

The approval of tarlatamab provides a welcome new option for this patient population.

What Is Tarlatamab?

Tarlatamab, also known by its brand name Imdelltra, is a new type of immunotherapy approved for people with small-cell lung cancer whose disease has progressed after chemotherapy and immunotherapy. It received full approval from the Food and Drug Administration (FDA) in late 2025, marking a major step forward for patients who previously had very limited options.

Unlike chemotherapy, which attacks cancer cells but also harms healthy cells, tarlatamab works by re-engaging the body’s immune system.

“Small-cell lung cancer often becomes invisible to the body’s natural defenses,” Dr. Alhamadi explains. “Our immune cells can’t see it or reach it.” Tarlatamab helps solve that problem.

She describes the drug as a “double-sided magnet.” One side attaches to a protein found on small-cell lung cancer cells, while the other side grabs immune cells and brings them face-to-face with the cancer. “It allows the body to take over and destroy the cancer cells,” she explains.

Tarlatamab’s Success: What It Means For Patients

In a large clinical study comparing tarlatamab with standard chemotherapy in the second-line setting, patients who received tarlatamab lived longer overall. More importantly, many of those responses lasted longer.

“The real story is in the durability of response,” Dr. Alahmadi says. “Chemotherapy may work briefly and then stop. But patients who responded to tarlatamab stayed stable much longer.”

Patients also experienced fewer side effects compared with chemotherapy. According to Dr. Alahmadi, the risk of side effects was cut nearly in half. Many patients regained strength, energy, and the ability to carry out daily activities.

“This is not just about improving survival by days,” she says. “It’s about adding life to those days.”

What Are The Side Effects?

Tarlatamab does have unique side effects, the most common being something called cytokine release syndrome (CRS). Symptoms associated with CRS can feel flu-like and may include fever, chills, sweating, or fatigue. Some patients notice changes in taste.

These effects usually happen early and are very manageable. “We typically see these symptoms in the first couple of doses,” Dr. Alahmadi says.

Patients are monitored closely — often in the hospital for the first one or two treatments — so symptoms can be treated quickly with fluids, Tylenol, or steroids if needed.

“The good news is we don’t see these side effects beyond cycle two or three,” she adds. “After that, the risk is almost zero, and patients often feel much better. These side effects can sound scary, but when they’re identified early, we can manage them before they become severe.”

Real World Results

Dr. Alahmadi has seen firsthand how meaningful this treatment can be. She recalls a teenage patient with small-cell lung cancer — an extremely rare and devastating diagnosis at that age — who had progressed through every available option.

After starting tarlatamab, the patient initially experienced side effects that were managed with steroids. Then something remarkable happened. He stabilized. He was able to graduate from school. He spent holidays with his family. It was time they never expected to have.

“That’s why we do this work,” she says. “This drug is amazing, but we’re always striving to do more — to help even more patients benefit.”

Looking to the future, clinical trials are already exploring tarlatamab earlier in treatment, even before chemotherapy. Dr. Alahmadi encourages patients not to rely on outdated statistics found online and to seek care at centers experienced in treating small-cell lung cancer.

“Breakthroughs like this are changing what’s possible,” she says.

Questions To Ask Your Doctor

• Am I eligible for tarlatamab based on my prior treatments?
• How does this treatment compare with chemotherapy for someone like me?
• What side effects should I expect in the first few doses, and how are they managed?
• Where will I receive my initial treatments, and can I continue closer to home later?
• Are there clinical trials available that might allow me to receive this treatment earlier?

Learn more about SurvivorNet's rigorous medical review process.

---