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Merus Merus Announces Regulatory Update on Zenocutuzumab , Financial Results for the Third Quarter and Provides Business Update November 2 , 2021 • Merus participated in a Type B meeting with the FDA regarding its zenocutuzumab development program and obtained alignment with FDA on registration approach for a potential tumor agnostic indication • Merus presented early clinical data on MCLA - 158 at the AACR - NCI - EORTC Virtual International Conference reporting interim data for patients with advanced head and neck squamous cell carcinoma ( HNSCC ) UTRECHT , The Netherlands and CAMBRIDGE , Mass . , Nov. 02 , 2021 ( GLOBE NEWSWIRE ) -- Merus N.V. ( Nasdaq : MRUS ) ( " Merus " , the " Company , " " we " , or " our " ) , a clinical - stage oncology company developing innovative , full - length multispecific antibodies ( Biclonics® and Triclonics® ) , today announced a regulatory update for the zenocutuzumab ( Zeno ) program in NRG1 positive ( NRG1 + ) solid tumors , financial results for the third quarter that ended September 30 , 2021 , and provided a business update . " Our recent regulatory interactions with the FDA demonstrate the maturation of the Zeno program as we continue on the path to potential BLA submission , " said Bill Lundberg , M.D. , President , Chief Executive Officer of Merus . " In addition , with MCLA - 158 , we are also encouraged by the early interim clinical data we recently reported in head and neck cancer , and the continued progress of our other clinical programs . We believe the positive results we are seeing in the clinic further validate the strength of our platform . " Clinical Programs Zenocutuzumab ( Zeno or MCLA - 128 : HER3 x HER2 Biclonics® ) Alignment obtained with the FDA on registration approach for a potential tumor agnostic indication : clinical update planned for 1H22 Merus met with the U.S. Food and Drug Administration ( FDA ) in an end - of - phase Type B meeting to discuss interim results from the ongoing phase 1/2 eNRGy trial and Early Access Program ( EAP ) in NRG1 + cancers , and to discuss the development plan for Zeno . Merus and the FDA officials discussed the available Zeno monotherapy data and a potential data package to support a biologics license application ( BLA ) submission . Merus designed the phase 1/2 eNRGY trial to support potential registration in either a tumor - specific or a tumor agnostic NRG1 + indication ( s ) . Based on feedback received from the FDA , Merus believes that the trial design and planned enrollment will be appropriate to potentially support a BLA submission seeking a tumor agnostic indication for Zeno in patients with previously treated NRG1 + cancers . Merus believes that , if the rate of enrollment and efficacy remains consistent , a sufficient number of patients will be enrolled in the eNRGy trial and EAP , with sufficient follow up , by mid - 2022 , that could provide a potential registrational data set . Andrew Joe , M.D. , Chief Medical Officer of Merus , stated , " We are very pleased with our recent regulatory interactions including alignment with the FDA on a tumor agnostic approach for NRG1 + cancers , for which Zeno has already received Fast Track designation . Regulatory interactions such as these represent continued progress in Merus ' mission to bring our novel multispecific antibody therapy candidates to patients with serious unmet medical need . " As of September 1 , 2021 more than 80 patients with NRG1 + cancers have been treated with Zeno monotherapy in our phase 1/2 eNRGy trial and EAP . Merus plans to provide a further clinical program update in the first half of 2022 . Details of the eNRGy trial can be found at www.ClinicalTrials.gov and Merus ' trial website at www.nrg1.com or by calling 1-833 - NRG - 1234 . In addition , we presented preclinical data on Zeno at the 2021 AACR - NCI - EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics . The bispecific HER2 / HER3 antibody Zeno blocked cell growth 100 fold more potently than the bivalent HER3 antibody derived from Zeno , in an NRG1 driven growth assay , and potently blocked NRG1 - fusion mediated downstream signaling and growth in in vitro and in vivo models . Zeno induced both antibody - dependent cellular cytotoxicity ( ADCC ) and antibody - dependent cellular phagocytosis ( ADCP ) mediated killing of cancer cells in a dose - dependent manner . MCLA - 158 ( petosemtamab : Lgr5 x EGFR Biclonics® ) : Solid Tumors Dose expansion continues in the phase 1 trial : update planned for 2022 We shared early interim clinical data of the MCLA - 158 program in patients with advanced HNSCC at the 2021 AACR - NCI - EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics . Among 10 patients with previously treated advanced HNSCC , as of the August 9 , 2021 safety and efficacy data cutoff , the median age was 65 and the median number of prior lines of therapy was two . Seven patients were evaluable for an interim efficacy analysis by investigator assessment ( three patients were enrolled < 8 weeks from the data cutoff date ) . Three of seven patients achieved a best response of partial response , with one achieving complete response after the data cutoff date . Tumor reduction was observed in the target lesions of all seven patients . The safety results presented for MCLA - 158 were based on 29 patients with advanced solid tumors who were treated at 1500 mg every two weeks across the phase 1 trial . The most frequent adverse events ( AEs ) were infusion related reactions with 72 % any grade and 7 % grade 3 or greater . Mild to moderate skin toxicity ( 3 % grade ≥3 ) was also observed . MCLA - 145 ( CD137 x PD - L1 Biclonics® ) : Solid Tumors