ALX Oncology Shares Phase 1 ASPEN-07 Evorpacept Combo Data for Advanced Bladder Cancer

ALX Oncology Holdings Inc., a company specializing in immuno-oncology, recently revealed promising data from its Phase 1 ASPEN-07 clinical trial. The trial investigates the combination of evorpacept and PADCEV® (enfortumab vedotin or “EV”) in patients with advanced urothelial cancer. The findings were presented in a poster session at the 2024 American Society of Cancer Oncology (ASCO) Annual Meeting.

Evorpacept is a CD47 blocker designed to reduce toxicity by having an inactive Fc effector domain. The clinical trial enrolled 28 patients who had not previously been treated with EV. These patients had all experienced disease progression after undergoing platinum chemotherapy and checkpoint inhibition. A significant proportion, around 93%, had metastatic disease, and nearly 29% had received three or more prior lines of therapy.

The combination of evorpacept and PADCEV was generally well tolerated even in this heavily pre-treated patient group. No maximum tolerated dose was identified, with the highest administered dose of evorpacept being 30 mg/kg biweekly. Common side effects included low-grade fatigue, dysgeusia, nausea, diarrhea, hyperglycemia, and pruritus, and there were no treatment-related deaths.

In terms of efficacy, the trial showed that the combination therapy resulted in a tumor reduction in most patients. As of the data cut-off date in April 2024, the overall response rate (ORR) was 59%. This rate increased to 61% with subsequent patient evaluations, including two complete responses and six partial responses. A majority of patients remained in the study, indicating sustained engagement and potential for ongoing benefit.

Sophia Randolph, M.D., Ph.D., Chief Medical Officer of ALX Oncology, expressed optimism about the preliminary results, noting that this was the first clinical demonstration of anti-tumor activity using a CD47 blocker in combination with an ADC in such a patient population. Jason Lettmann, CEO of ALX Oncology, also highlighted the significance of the complete responses observed, expressing hope for improved outcomes as the study progresses.

The ASPEN-07 trial continues to enroll new cohorts and to follow up with patients who have not previously been treated with EV. The company plans to further evaluate clinical development options for both PADCEV-naïve and experienced patients.

ALX Oncology will host a virtual event to discuss the trial results and their implications for future treatment paradigms. The event will feature Dr. Samuel A. Funt from Memorial Sloan Kettering Cancer Center, who is the principal investigator for ASPEN-07. Dr. Funt is an expert in bladder cancer and has extensive experience in clinical trials focusing on genitourinary oncology.

The ongoing trial aims to assess the safety, tolerability, and efficacy of evorpacept combined with EV in patients with advanced bladder cancer. The trial involves dose escalation and has so far included patients receiving either 20 mg/kg or 30 mg/kg of evorpacept biweekly alongside standard EV treatment.

Bladder cancer is a significant health concern, being the sixth most common cancer type in the United States. Urothelial carcinoma (UC) is its most prevalent form, accounting for about 90% of cases. In 2024, it is estimated that there will be approximately 83,000 new cases of bladder cancer in the U.S., with 16,800 resulting in death.

ALX Oncology is committed to advancing cancer treatment through its innovative CD47 blocking therapeutic, evorpacept. This drug has shown a favorable safety and efficacy profile in various hematologic and solid malignancies. The company's strategy focuses on combining evorpacept with other anti-cancer antibodies, ADCs, and PD-1/PD-L1 inhibitors to enhance the immune system's ability to combat cancer.

Overall, the initial data from the ASPEN-07 clinical trial are promising, indicating that evorpacept, in combination with PADCEV, could offer a new treatment avenue for patients with advanced urothelial cancer. The company is optimistic about the potential for improved patient outcomes as further data is collected and analyzed.