FDA Grants Two Designations to TT125-802 for Mutated Lung Cancers

The U.S. Food and Drug Administration (FDA) has granted two fast track designations to TT125-802, an investigational therapy, for the treatment of patients with advanced or metastatic non-small cell lung cancer (NSCLC), according to a news release from TOLREMO therapeutics.

The designations include patients with either epidermal growth factor receptor (EGFR) mutations or KRAS-G12C mutations whose disease has worsened after prior therapies, including targeted inhibitors.

“NSCLC is a major cause of cancer-related death. While oncogene-targeting drugs such as EGFR and KRAS inhibitors improve survival, a significant number of patients eventually experience disease progression,” said Dr. Stefanie Flückiger-Mangual, CEO at TOLREMO. “TT125-802 has the potential to address this challenge by blocking transcriptional pathways that drive tumor growth and treatment evasion in parallel to the driving oncogene.”

TT125-802 is an orally available small-molecule inhibitor. Unlike some agents in this class, TT125-802 has shown a favorable safety profile without causing thrombocytopenia, a serious side effect involving dangerously low platelet counts.

Data from the ongoing phase 1 trial, presented at the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting, highlighted encouraging single-agent activity in patients with solid tumors, including those with EGFR- and KRAS-G12C–mutated NSCLC. Several patients achieved durable responses, underscoring the potential of TT125-802 as a backbone therapy for drug-resistant disease, according to the news release.

“TT125-802’s highly selective mechanism of action and favorable safety profile differentiate it from other agents,” said Dr. Alan Sandler, Scientific Advisory Board member at TOLREMO. “The fast track designations highlight its potential to provide a new approach for tackling resistance and tumor survival in patients with EGFR- and KRAS-G12C–mutant NSCLC.”

The FDA’s fast track designation provides multiple advantages during clinical development, including more frequent communication with the agency, eligibility for rolling review of data, and potential priority review or accelerated approval if certain criteria are met. These benefits may help speed the availability of TT125-802 to patients who urgently need additional treatment options.

Addressing an Unmet Need in Lung Cancer Treatment

Lung cancer remains the leading cause of cancer-related death in the United States, accounting for approximately one in five cancer deaths each year. NSCLC represents nearly 87% of all lung cancer cases, and an estimated 30% of these tumors harbor either an EGFR mutation or a KRAS-G12C mutation. Although targeted therapies such as EGFR inhibitors and KRAS inhibitors have improved outcomes for many patients, resistance often develops, leaving few treatment options when the disease progresses.

Metastatic lung cancer, also called advanced lung cancer, occurs when cancer spreads from the lungs to other organs, such as the brain, bones, liver, or adrenal glands, according to the Cancer Research UK website. In many cases, advanced disease cannot be cured, although treatments may help control the cancer, relieve symptoms, and improve quality of life. The FDA’s Fast Track program is designed to accelerate the development of therapies for serious conditions where there is high unmet medical need, offering patients quicker access to treatments.

What’s Next for TT125-802 in Lung Cancer?

TOLREMO continues to advance TT125-802 through its multicenter, first-in-human phase 1 trial, which is assessing the drug’s safety, tolerability, pharmacokinetics, and preliminary efficacy across advanced solid tumors. Building on the early findings, the company also plans to investigate TT125-802 in combination with oncogene-targeted therapies for patients with EGFR- and KRAS-mutated NSCLC.

Although additional clinical testing is needed, the fast track designations represent an important milestone in the development of TT125-802 and reinforce the need for innovative strategies to overcome resistance in lung cancer treatment.

“By working closely with the FDA under the Fast Track program, we hope to deliver on our mission to bring differentiated treatment approaches to patients with urgent unmet needs,” Flückiger-Mangual said.

References

1. “TOLREMO Therapeutics Receives Two FDA Fast Track Designations for TT125-802 in Pretreated, Advanced or Metastatic NSCLC With Either an EGFR or a KRAS-G12C Mutation,” by TOLREMO Therapeutics. News release; Aug. 28, 2025.
2. “What is Metastatic Lung Cancer?” by Cancer Research UK. https://www.cancerresearchuk.org/about-cancer/lung-cancer/metastatic/what-is

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