# Bispecific antibody for topical administration to prevent gonorrhea > **NIH NIH R43** · PLANET BIOTECHNOLOGY, INC. · 2024 · $299,999 ## Abstract 1 Gonorrhea affects over 80 million individuals globally, annually. Over 700,000 cases were reported to the CDC 2 in 2021, a relentless rise since 2009. Women suffer the most serious consequences of this disease, including 3 pelvic inflammatory disease, ectopic pregnancy and infertility. The etiologic agent, Neisseria gonorrhoeae (Ng) 4 has become resistant to almost every antibiotic in clinical use. The emergence of ceftriaxone-resistant isolates 5 in all regions of the world portends an era of untreatable gonorrhea. There is no licensed vaccine against 6 gonorrhea. Thus, safe and effective preventive measures are urgently needed. Ng evade killing by complement 7 (C’) by sialylating its lipooligosaccharide (LOS), which results in recruitment of the C’ inhibitor, factor H (FH). To 8 exploit this virulence mechanism, we fused the Ng-binding fragment of FH (that lacks C’ inhibitory activity) to the 9 C-terminus of human IgG3 Fc to produce Fc3/FH*. Fc3/FH* killed all 46 Ng isolates that expressed the PorB1B 10 allele of the major outer membrane porin B (PorB) protein in a C’-dependent bactericidal assay, and diminished 11 the duration and burden of Ng in the mouse vaginal colonization model. However, Fc3/FH was bactericidal 12 against only 2 of 15 Ng strains that expressed the PorB1A allele. Although responsible for only a minority of 13 infections, PorB1A isolates have a relatively high propensity to disseminate through the bloodstream. To reliably 14 cover PorB1A isolates, we will create a novel bispecific mAb where the C-terminus of FH will be fused to an anti- 15 LOS mAb called 2C7. mAb 2C7 recognizes an epitope distinct from LOS sialic acid, which is critical for Fc3/FH 16 binding. Further, mAb 2C7 binds independently of the PorB allele expressed. The 2C7 LOS epitope is critical for 17 Ng colonization, and therefore expressed by >95% of Ng in vivo. A chimeric version of mAb 2C7 shows C’- 18 dependent killing of all minimally passaged Ng tested and attenuates mouse vaginal colonization by both PorB1A 19 and PorB1B Ng. The advantages of the bispecific 2C7/FH* mAb include: 1) broad activity against PorB1A and 20 PorB1B Ng; 2) a substantially raised threshold for the development of drug-resistance by targeting two distinct 21 epitopes and virulence factors; and 3) reduced cost of production compared to producing two separate molecules 22 – a critical consideration for Ng therapeutics because gonorrhea rates are highest among socio-economically 23 underprivileged and marginalized populations and in low- and middle-income countries. In Aim 1, we will produce 24 four bispecific mAbs that contains FH domains 19-20 or domain 20 alone fused to the C-terminus of either the 25 heavy or light chain of chimeric mAb 2C7. A 6-month accelerated stability study will be carried out on the 26 bispecifics. In Aim 2, we will compare the efficacy of the four bispecifics in vitro using C’-dependent bactericidal 27 assays against a small panel of Ng isolates. T... ## Key facts - **NIH application ID:** 11013480 - **Project number:** 1R43AI186979-01 - **Recipient organization:** PLANET BIOTECHNOLOGY, INC. - **Principal Investigator:** SANJAY RAM - **Activity code:** R43 (R01, R21, SBIR, etc.) - **Funding institute:** NIH - **Fiscal year:** 2024 - **Award amount:** $299,999 - **Award type:** 1 - **Project period:** 2024-08-01 → 2026-07-31 ## Primary source NIH RePORTER: https://reporter.nih.gov/project-details/11013480 ## Citation > US National Institutes of Health, RePORTER application 11013480, Bispecific antibody for topical administration to prevent gonorrhea (1R43AI186979-01). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/11013480. Licensed CC0. --- *[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*