Minghui Pharma Shares Phase 1/2 Data on MHB088C for Solid Tumors at 2024 ASCO Meeting

Minghui Pharmaceutical, Inc., a biopharmaceutical company in its late clinical stages, has unveiled promising preliminary Phase 1/2 data for the novel drug MHB088C (B7-H3 ADC) at the 2024 American Society of Clinical Oncology (ASCO) Annual Meeting. This investigational treatment, a B7-H3 Antibody-Drug Conjugate (ADC), targets recurrent or metastatic solid tumors and incorporates a potent DNA Topoisomerase I inhibitor.

The Phase 1/2 study focused on evaluating the safety, tolerability, pharmacokinetics, and efficacy of MHB088C in patients with various recurrent or metastatic solid tumors. The results thus far have been promising, with MHB088C being generally well-tolerated. Hematological toxicities were the most common treatment-related adverse events (TRAEs), but the drug demonstrated a favorable safety profile at doses of 1.6 mg/kg Q2W, 2.0 mg/kg Q3W, and 2.4 mg/kg Q3W. The dose-limiting toxicity (DLT) was identified at 4 mg/kg Q3W, and the maximum tolerated dose (MTD) was established at 3 mg/kg Q3W. Notably, there were no reported cases of interstitial lung disease (ILD) as of the data cutoff.

For efficacy, the data was analyzed from 98 patients with various tumor types receiving doses from 0.8 mg/kg to 4.0 mg/kg. The overall response rate (ORR) was 33.7%, and the disease control rate (DCR) was 83.7%, with the duration of response (DoR) yet to be determined. The majority of these patients are still undergoing treatment.

Focusing on specific cancer types, the study highlighted significant efficacy in small cell lung cancer (SCLC) patients: among 31 evaluable patients, the ORR was 61.3%, and the DCR was 93.5%. About 77.4% of these patients continue with the treatment, and 19.4% achieved a 60% or more reduction in tumor size, with two complete responses (CRs) noted at the 3.0 mg/kg dosage. Additionally, a subset of 10 SCLC patients treated with 1.6 mg/kg Q2W had an ORR of 80% and a DCR of 90%.

For patients with esophageal squamous cell carcinoma (ESCC), out of seven evaluable patients, the ORR was 42.9%, and the DCR was 85.7%, with a median follow-up exceeding three months.

Professor Lin Shen from Beijing Cancer Hospital remarked on the innovative nature of MHB088C, emphasizing its clinically significant and durable antitumor activities at very safe doses across multiple cancer types. He expressed optimism for the continuing study and future positive outcomes.

Dr. Guoqing Cao, CEO of Minghui Pharmaceutical, shared enthusiasm about the Phase 1/2 study results presented at ASCO. He noted that MHB088C is distinguished by its robust efficacy at very safe doses without major hematological toxicity or ILD. He particularly highlighted the impressive results in SCLC, where the ORR reached 80% among patients treated with 1.6 mg/kg Q2W. He also mentioned the notable response durability in ESCC.

The safety profile of MHB088C aligns with another of Minghui's ADC programs, MHB036C, showing no major hematological toxicity or ILD. With data from over 250 patients, Minghui Pharmaceutical believes it holds one of the leading ADC platforms in the industry. The company plans to initiate registrational trials for MHB088C as a monotherapy for selected tumor types by the end of 2024, as well as to explore immune-oncology (IO) combinations in earlier treatment settings.

MHB088C leverages Minghui's SuperTopoiTM ADC platform, featuring a payload significantly more potent than DXd and equipped with a proprietary B7-H3 antibody that shows superior binding and internalization properties. This has resulted in remarkable anti-tumor efficacy across various cancer types, outperforming competitors' compounds in preclinical models.

Minghui Pharmaceutical is dedicated to developing innovative treatments for oncology and autoimmune diseases, utilizing proprietary technology platforms to advance a strong clinical-stage pipeline of first-in-class or best-in-class product candidates.