Benzinga | Nov 9, 2020 08:21AM EST

ALX Oncology Announces New Data from ASPEN-01, the Phase 1b Study of ALX148, Showing Promising Initial Clinical Responses in Patients with Advanced Solid Tumors

ALX Oncology Holdings Inc., ("ALX Oncology") (NASDAQ:ALXO), a clinical-stage immuno-oncology company developing therapies to block the CD47 checkpoint mechanism, today announced new results from ASPEN-01, the ALX148 Phase 1b study, evaluating patients with solid tumor malignancies at the Society for Immunotherapy of Cancer's 35th Anniversary Annual Meeting [abstract 404].

ALX Oncology reports new preliminary data from the gastric/gastroesophageal junction cancer ("GC") patient cohort receiving ALX148 plus trastuzumab plus chemotherapy, and from the head and neck squamous cell carcinoma ("HNSCC") patient cohort receiving ALX148 plus pembrolizumab plus chemotherapy. In addition, updated data are presented from the GC patient cohort receiving ALX148 plus trastuzumab, and from the HNSCC patient cohort receiving ALX148 plus pembrolizumab. All data reflect response evaluable patients as of October 1, 2020.



* In patients with >2L HER2 positive GC (n=14), whose tumors have progressed upon prior trastuzumab therapy, ALX148 demonstrates a promising initial objective response rate (ORR) of 64% in combination with trastuzumab plus ramucirumab and paclitaxel that compares favorably with historical data.

* In initial patients with 1L HNSCC who have not received prior treatment for their advanced disease (n=4), ALX148 demonstrates a promising initial ORR of 75%, including a complete response, in combination with pembrolizumab plus 5-fluorouracil and platinum.

* Updated data from patients with >2L HER2 positive GC receiving ALX148 plus trastuzumab suggests promising clinical activity after their tumors have progressed upon prior trastuzumab therapy.

* Updated data from patients who have never been treated with a PD-1/PD-L1 inhibitor for their >2L HNSCC and who received ALX148 plus pembrolizumab suggests clinical activity beyond that expected from pembrolizumab monotherapy.

* Preliminary data suggests that ALX148 can be safely combined with multi-agent chemotherapy regimens studied with no maximum tolerated dose reached. The maximum administered dose of ALX148 in combination was 15 mg/kg once per week.

"This remarkable emerging data suggest that ALX148 in combination with the standard chemotherapy based regimens studied may induce meaningful clinical benefit in patients with advanced HER2 positive gastric as well as head and neck cancers," said Dr Keun-Wook Lee, Professor of Internal Medicine at Seoul National University College of Medicine, and Chief of The Clinical Trials Center at Seoul National University Bundang Hospital, South Korea.

"To our knowledge, these data are the first to support this degree of clinical activity in patients with solid tumors by a CD47 targeted agent," said Dr. Sophia Randolph, M.D., Ph.D., Chief Medical Officer, ALX Oncology. "Importantly, these results and ALX148's favorable tolerability profile further differentiate it from other CD47 targeted approaches, and we look forward to continuing its clinical development in our robust phase 2 program."