The FDA granted ALX Oncology’s head and neck cancer drug a fast-track tag in February, but, now, it’s telling the company to hold its horses. The agency placed a partial clinical hold on the program, allowing it to enroll a maximum of 50 patients across two pivotal trials while it wraps up a nonclinical safety study.
The hold is not related to any side effects seen in clinical trials of the drug, ALX148, said ALX Chief Medical Officer Sophia Randolph, M.D., Ph.D., in a statement Monday.
RELATED: Gilead strikes $4.9B Forty Seven acquisition, paying a hefty premium for cancer drug
The FDA “verbally informed the Company that given its planned initiation of two Phase 2 [head and neck squamous cell carcinoma] studies that could potentially be registrational, they require completion of a routine non-clinical safety study that the Company currently has in process,” ALX said in the statement.
Despite the hold, ALX expects no delays to the drug’s development and plans to send the safety study report to the FDA before it recruits 50 patients for the phase 2 studies.
The company is developing ALX148 for cancers of the stomach, esophagus and breast as well as for head and neck cancer. It works by blocking CD47, which is expressed at high levels in multiple cancers and sends out a “don’t eat me” signal to evade the immune system.
The phase 2 studies will test the drug in combination with Merck’s PD-L1 blocker Keytruda in patients with head and neck cancer that has spread, returned in spite of other treatment or can’t be treated with surgery. Both will test the combo as a first-line treatment, but one trial will recruit patients whose tumors express PD-L1 above a certain threshold while the second will recruit patients regardless of PD-L1 status.
RELATED: ALX raises $105M for midphase trials of CD47 cancer drug
ALX148 grabbed two fast-track tags from the FDA in February, one for the first-line treatment of head and neck cancer and the other for the second-line treatment of patients with HER2-positive gastric or gastroesophageal junction carcinoma. The speedy tags came barely a week after the biotech raised a $105 million series C to bankroll phase 2 studies of ALX148.