Small cell lung cancer (SCLC) often responds well to initial treatment before later relapsing. Researchers are continuing to investigate new treatments, such as targeted therapy and immunotherapy drugs.

Clinical trials are studies where researchers investigate new drugs or combinations of drugs to treat a condition. If they find that the new treatment is more effective than the current standard treatment, the drug might become the new standard treatment.

When considering how to best treat SCLC, researchers commonly divide SCLC into:

  • Limited stage: The cancer is only on one side of your chest and can be treated with a single radiation field. The cancer may have reached lymph nodes on the same side of your chest.
  • Extensive stage: The cancer has spread widely throughout your lung, to your other lung, or other parts of the body.

Many current and recently completed clinical trials are looking at new treatments for extensive stage SCLC, which has a particularly less favorable outlook.

This article examines some of the newest treatments for SCLC, treatments under investigation, and current standard treatment.

What is SCLC?

SCLC is a rare but aggressive cancer that makes up roughly 10% to 15% of lung cancers. It gets its name from the microscopic appearance of cancer cells. It’s highly linked to smoking.

SCLC survival rates have only marginally improved over the last several decades in the United States. The 5-year relative survival rate of SCLC remained under 9% in the United States from 2014 to 2020. This means 9% of people with SCLC are living 5 years after their diagnosis than people without SCLC.

Learn more about SCLC.

The Food and Drug Administration (FDA) has recently approved the following SCLC treatments in the United States.

Imdelltra for extensive stage SCLC

The FDA granted accelerated approval to the medication Imdelltra (tarlatamab-dlle) on May 16, 2023, for extensive stage SCLC. This immunotherapy drug is administered as an injection over 1 hour every week for three doses and then every 2 weeks afterward.

In clinical trials, 44% of 99 people with extensive stage SCLC whose cancer relapsed or didn’t respond to treatment had complete or partial shrinkage of their tumors. Forty percent of people whose cancers responded had shrinkage lasting more than 1 year.

Trilaciclib to reduce chemotherapy side effects

Cosela (trilaciclib) was FDA approved on February 12, 2021, to help reduce chemotherapy-induced myelosuppression in people with extensive stage SCLC. Myelosuppression is when the cells in your bone marrow no longer adequately produce blood cells. This medication does not treat the cancer itself.

Reducing myelosuppression can potentially allow doctors to administer a higher dose of chemotherapy, which may help destroy more cancer cells and improve survival.

Cosela is administered through an IV before each dose of chemotherapy.

Durvalumab for extensive stage SCLC

On March 27, 2020, the FDA approved the immunotherapy drug Imfinzi (durvalumab) in combination with the chemotherapy drugs etoposide and either carboplatin or cisplatin as the first-line treatment for people with extensive stage SCLC.

In the clinical trial that led to its approval, half of the people who received durvalumab plus chemotherapy survived 13 months compared with 10.3 months in people who received chemotherapy alone.

Lurbinectedin for metastatic SCLC

The FDA granted accelerated approval for the chemotherapy drug Zepzelca (lurbinectedin) on June 15, 2020, for people with metastatic SCLC.

Metastatic SCLC means the cancer has spread to distant tissues. In clinical trials, the overall response rate of Zepzelca was 35%. For half of the people in the trial, their cancer responded for longer than 5.3 months.

Many clinical trials are currently examining new treatment options for SCLC. Treatments under investigation include the following.

Ivonescimab

Ivonescimab is a targeted therapy drug currently under investigation for treating extensive stage SCLC in combination with another targeted therapy drug called cadonilimab.

It’s currently in phase 2 clinical trials, which are expected to be completed by 2027.

PM8002

PM8002 is an immunotherapy drug currently under investigation with another medication called paclitaxel as a second-line treatment for SCLC compared to chemotherapy. A second-line therapy is one performed when the first treatment doesn’t work.

Doctors currently use paclitaxel by itself as a chemotherapy medication to treat cancer.

PM8002 is currently in phase 3 clinical trials, which are expected to be completed by 2028.

Adebelimab

Researchers are currently examining the effectiveness of the targeted therapy drug adebelimab combined with chemotherapy as a first-line treatment for extensive stage SCLC. A phase 2 clinical trial is expected to be completed by 2028.

A phase 3 clinical trial that’s expected to be finished by 2028 is examining the effectiveness of adebrelimab and chemotherapy with low dose radiation therapy as the initial treatment for extensive stage SCLC.

IBI3009

A phase 1 clinical trial is examining the effectiveness of the targeted therapy drug IBI3009 in people with locally advanced or metastatic SCLC that can’t be treated surgically. It’s expected to be completed by 2027.

YL201

A phase 3 clinical trial expected to be completed by 2030 is examining the effectiveness and safety of the targeted therapy drug YL201 with topotecan hydrochloride for people with relapsed SCLC.

ZG006

Researchers are examining the safety, effectiveness, and tolerability of the immunotherapy drug ZG006 for treating SCLC that did not respond to or is not eligible for standard treatment. A phase 1 clinical trial is expected to be completed in 2027.

Tarlatamb

A phase 1 clinical trial is examining the effectiveness of the immunotherapy drug tarlatamb for treating extensive stage SCLC. It’s expected to be completed in 2028.

Treatment options for SCLC depend on the stage of cancer. Current treatment options include the following.

Limited stage SCLC

Current treatments for SCLC include:

  • a combination of chemotherapy drugs and radiation therapy to the chest with radiation therapy later given to the brain if there is a complete response
  • a combination of chemotherapy drugs alone
  • surgery followed by chemotherapy or chemotherapy combined with radiation therapy
  • radiation therapy to the brain in cancers that have had a complete response to surgery
  • clinical trials of new drugs and combinations of treatment

Extensive stage SCLC

Treatment for extensive stage SCLC includes:

  • the immunotherapy drugs atezolizumab or durvalumab with a combination of chemotherapy drugs
  • a combination of chemotherapy drugs
  • radiation therapy to areas where the cancer has spread as a palliative treatment
  • radiation to the chest if cancer responds to chemotherapy
  • radiation to the brain after a complete response to chemotherapy

Researchers are currently investigating many drugs to treat SCLC. The outlook for people with SCLC in the United States still remains less favorable. Researchers remain hopeful that future treatments like targeted therapy and immunotherapy drugs will help improve survival.

Your doctor can help you figure out whether you might be eligible for clinical trials examining the effectiveness of new treatments. You can also find clinical trials on ClinicalTrials.gov.