eFFECTOR Therapeutics has discontinued the development of tomivosertib as a frontline treatment for non-small cell lung cancer (NSCLC) following negative topline results.

The Phase II KICKSTART trial was investigating tomivosertib in combination with MSD’s Keytruda (pembrolizumab) in patients with NSCLC with programmed death-ligand 1 (PD-L1) expression in tumours higher than 50%. Patients receiving the combo were compared to those receiving a placebo along with Keytruda.

The US biotech reported the trial did not meet the primary endpoint of hazard ratio for progression-free survival. Additionally, eFFECTOR did not discern a trend favouring tomivosertib for overall survival.

Whilst eFFECTOR’s combo therapy led to modest improvements, there were 67% treatment-emergent adverse events in the tomivosertib treatment arm compared to 37% receiving the placebo combo.

eFFECTOR’s Steve Worland said: “Based on the totality of the data currently available we do not see an obvious path forward to continue developing tomivosertib in frontline NSCLC.”

Worland said focus will now shift to the company’s other pipeline candidates, including eIF4A inhibitor Zotatifin for the treatment of breast cancer.

Earlier this month, AstraZeneca reported positive data from its FLAURA2 Phase III clinical trial of Tagrisso (osimertinib) combined with chemotherapy. MAIA Biotechnology also unveiled positive efficacy data from its Phase II THIO-101 clinical trial of THIO sequenced with cemiplimab (Libtayo).

NSCLC is the most common type of lung cancer. In 2024, it is estimated there will be nearly 235,000 new cases of lung cancer.

The NSCLC market is largely dominated by Keytruda, which saw $25bn in global sales last year. Across 15 global markets, the NSCLC market is predicted to reach over $45.4bn in total by 2031, according to a report by GlobalData.

GlobalData is the parent company of Clinical Trials Arena.