Inhibrx's combination cancer drug shrinks tumors in mid-stage head and neck cancer study

Sept 8 — Inhibrx Biosciences said on Tuesday its experimental combination cancer drug helped ​reduce tumors in a mid-stage study in patients with a type of head and neck cancer.

• In a 68-patient trial for head and neck ‌squamous cell carcinoma that has spread and is inoperable, the drug INBRX-106 combined with Keytruda shrank or eliminated ⁠tumors in 48.3% of patients, versus ​26.5% for Keytruda alone.

• The benefit ⁠was strongest in patients with HPV-positive disease, with tumors shrinking in 80% of patients ‌who received the combination ‌therapy, compared with 33.3% of those treated with Keytruda alone.

• The ⁠company said it plans to enroll about 50 ⁠more patients with oropharyngeal cancer linked to human papillomavirus (HPV), a common infection that can cause throat and cervical cancers, to support a potential accelerated approval.

• "I think what matters to investors here is that this company went after this really difficult biological target, OX40, and were able to produce not just ‌efficacious, but competitive results," said Stifel analyst Dara Azar, ​adding "we feel good based on...reviewing the data and seeing the numeric proof."

• Inhibrx estimates about 30,000 HPV-positive head and neck cancer patients in the U.S. by 2029, of which about 6,000 are first-line recurrent patients representing a $1 billion annual sales opportunity.

• Shares of the company, however, were down 8.8% at $110.45.

• "We can't provide any explanation for the stock movement today, but it's a great entry ​point for anyone looking at the stock. Today's data was very de-risking for the program," ‌said CEO Mark ‌Lappe. The ⁠HPV-positive results don't limit where we can go but just the opposite, he added.

• INBRX-106 is an immunotherapy designed to activate OX40, a protein on T cells that helps boost the body's immune response.

• Other drugs targeting the OX40 pathway, including Amgen ‌and Kyowa Kirin's rocatinlimab ​and Sanofi's amlitelimab, have been discontinued.

• The company ‌also plans to explore ⁠the potential of ​INBRX-106 in combination with therapeutic cancer vaccines.

(Reporting by Sneha S K in Bengaluru; Editing by ​Vijay Kishore)

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