monomethyl-auristatin-e and Stomach-Neoplasms

Disitamab vedotin (Aidixi

Topics: Antibodies, Monoclonal; Antineoplastic Agents; Drug Approval; Drug Development; Humans; Immunoconjugates; Neoplasms; Oligopeptides; Receptor, ErbB-2; Stomach Neoplasms

RC48 contains the novel humanized anti-HER2 antibody hertuzumab conjugated to MMAE via a cleavable linker. A phase I study was initiated to evaluate the toxicity, MTD, PK, and antitumor activity of RC48 in patients with HER2-overexpressing locally advanced or metastatic solid carcinomas, particularly gastric cancer.. This was a 2-part phase I study. Successive cohorts of patients received escalating doses of RC48 (0.1 mg/kg, 0.5 mg/kg, 1.0 mg/kg, 2.0 mg/kg, 2.5 mg/kg, and 3.0 mg/kg). Dose expansion proceeded at the dose of 2.0 mg/kg Q2W. The efficacy and safety set included all patients who received at least one dose of RC48.. Fifty-seven patients were enrolled, the MTD was unavailable due to termination of 3.0 mg/kg cohort; 2.5 mg/kg Q2W was declared the RP2D. RC48 was well tolerated, the most frequent grade 3 or worse TRAEs included neutropenia (19.3%), leukopenia (17.5%), hypoesthesia (14.0%), and increased conjugated blood bilirubin (8.8%). Four deaths occurred during the whole study, three of which were believed to be related to RC48. Overall, ORR and DCR were 21.0% (12/57) and 49.1% (28/57). Notably, patients who were HER2 IHC2+/FISH- responded similarly to those who were IHC2+/FISH+ and IHC3+, with ORRs of 35.7% (5/14), 20% (2/10), and 13.6% (3/22), respectively. In patients who were pretreated with HER2-targeted drugs, RC48 also showed promising efficacy, with ORR of 15.0% (3/20) and DCR of 45.0% (9/20).. RC48 was well tolerated and showed promising antitumor activity in HER2-positive solid tumors, including gastric cancer with HER2 IHC 2+/FISH- status.. NCT02881190.

Topics: Adult; Aged; Antibodies, Monoclonal, Humanized; Antineoplastic Agents, Immunological; Female; Humans; Immunoconjugates; Male; Maximum Tolerated Dose; Middle Aged; Oligopeptides; Receptor, ErbB-2; Stomach Neoplasms; Treatment Outcome

Gastric cancer is a worldwide health problem. Chemotherapy and radiotherapy are of great importance in the management of advanced gastric cancer. However, their therapeutic efficacy is limited by off-target side effects. Peptide-drug conjugates (PDCs) are a novel strategy for tumor-targeted drug delivery to overcome the existing drug resistance mechanisms and improve antitumor effects. Kita-Kyushu lung cancer antigen 1 (KK-LC-1) is exclusively expressed in several types of cancer including gastric cancer, representing a promising target for drug delivery. Here, we suggested KK-LC-1 as a potential target for PDC design for the first time and reported the first KK-LC-1-targeting PDC product 1131-MMAE, which is composed of a KK-LC-1-targeting peptide and an antimitotic drug conjugated by an enzymatically cleavable linker. We observed that 1131-MMAE could be efficiently endocytosed by KK-LC-1 positive gastric cancer cells for subsequent drug release and arrest the cell cycle at the most radiosensitive G2/M phase. We demonstrated that 1131-MMAE could significantly delay tumor growth with reduced toxicity than free drugs as a monotherapy. We further confirmed that 1131-MMAE was also a potent radiosensitizer. 1131-MMAE could selectively enhance the radiation response of KK-LC-1 positive tumor cells and achieve improved tumor control when combined with low-dose radiation. Overall, our study proposed an optimized therapeutic regimen for precision chemoradiotherapy, which has translational potential in multiple types of cancer.

Topics: Aminobenzoates; Antigens, Neoplasm; Cell Line, Tumor; Chemoradiotherapy; Humans; Immunoconjugates; Lung Neoplasms; Oligopeptides; Stomach Neoplasms; Xenograft Model Antitumor Assays

Carcinoembryonic antigen (CEA) is a classic tumor-specific antigen that is overexpressed in several cancers, including gastric cancer. Although some anti-CEA antibodies have been tested, to the best of our knowledge, there are currently no clinically approved anti-CEA antibody therapies. Because of this, we have created the novel anti-CEA antibody, 15-1-32, which exhibits stronger binding to membrane-bound CEA on cancer cells than existing anti-CEA antibodies. 15-1-32 also shows poor affinity for soluble CEA; thus, the binding activity of 15-1-32 to membrane-bound CEA is not influenced by soluble CEA. In addition, we constructed a 15-1-32-monomethyl auristatin E conjugate (15-1-32-vcMMAE) to improve the therapeutic efficacy of 15-1-32. 15-1-32-vcMMAE showed enhanced antitumor activity against gastric cancer cell lines. Unlike with existing anti-CEA antibody therapies, antitumor activity of 15-1-32-vcMMAE was retained in the presence of high concentrations of soluble CEA.

Topics: Animals; Antibodies, Monoclonal; Carcinoembryonic Antigen; Cell Line, Tumor; Cell Proliferation; Cell Survival; Humans; Mice; Oligopeptides; Stomach Neoplasms

Antibody-drug conjugate (ADC) is a novel class of therapeutics for cancer target therapy. This study assessed antitumor activity of ADC with an antimitotic agent, monomethyl auristatin E (MMAE) and a humanized monoclonal anti-HER2 antibody, hertuzumab, in gastric cancer. The efficacy of hertuzumab-MC-Val-Cit-PAB-MMAE (hertuzumab-vcMMAE) on human epidermal growth factor receptor 2 (HER2) positive human gastric cancer cells, NCI-N87, was evaluated in vitro and in vivo. The cytotoxicity of hertuzumab was significantly enhanced after conjugation with MMAE. Compared to trastuzumab, hertuzumab had a higher affinity to HER2 and had more potent antibody-dependent cell-mediated cytotoxicity (ADCC) activity in vitro. After conjugation with MMAE, the binding specificity for HER2 was not affected. Furthermore, the internalization of hertuzumab-vcMMAE in HER2 positive gastric cancer cells was verified. Although the conjugation of hertuzumab and MMAE decreased the ADCC effect, the overall cytotoxicity was dramatically increased in HER2 positive gastric cancer cells. In vitro data on this hertuzumab-vcMMAE has exerted much stronger antitumor activity compared to trastuzumab-DM1 in HER2 positive gastric cancer cells. A single administration of hertuzumab-vcMMAE at 5 or 10 mg/kg showed high potency and a sustained tumor inhibitory effect on NCI-N87 xenografts in mice. In conclusion, hertuzumab-vcMMAE conjugate is a highly effective anti-HER2 targeted therapy for HER2-positive gastric cancer.

Topics: Animals; Antibodies, Monoclonal; Cell Line, Tumor; Disease Models, Animal; Humans; Mice; Mice, Nude; Oligopeptides; Receptor, ErbB-2; Stomach Neoplasms; Xenograft Model Antitumor Assays