COVID-19 research and development (R&D) has started to see the first set of novel drug candidates enter clinical trials by way of monoclonal antibodies (mAbs). Experts interviewed by GlobalData see potential in these but are cautious that the cocktail strategy may not pan out better than treating with a single mAb, according to reporting from Manasi Vaidya, Pharma Writer for the Investigative News team at GlobalData, a leading data and analytics company.

Vaidya adds: “Beyond their treatment potential, when it comes to preventing infection, mAbs will likely be most applicable to the post-exposure setting.

“While the clinical development landscape has, so far, largely focused on repurposing existing drugs and investigating vaccines, mAbs for COVID-19 provide a novel and attractive approach for targeting the SARS-CoV-2 virus.

“At this stage, Eli Lilly and Regeneron have begun clinical trials, and Sorrento plans to file an investigational new drug application at July end or early August to start a Phase I trial.”

Lilly and its partner AbCellera have started a monotherapy trial of LY-CoV-555, while Lilly and another partner, Junshi Biosciences, have initiated a second monotherapy trial of JS-016. Furthermore, Sorrento is advancing STI-1499. However, Regeneron has kicked off with a combination of REGN10933 and REGN10987.

Vaidya continues: “Experts interviewed by GlobalData were keen to first see monotherapy data, noting that, while combinations are attractive, their potential to provide additive efficacy was unknown and could instead inadvertently interfere. Either way, it was noted that mAbs have the most potential when administered soon after disease onset, even when patients are not yet symptomatic or have only mild symptoms. Yet, considering the infection does not always progress to serious disease, it is difficult to identify who may be best suited to this treatment.”

Lilly and Regeneron are also exploring mAbs in various prophylactic settings, including pre-exposure and post-exposure.

Vaidya continues: “Experts saw mAbs as an opportunity to fill the likely need for a quick intervention in case of viral exposure, which vaccines cannot address. In the pre-exposure prophylactic setting that vaccines are being tested in, mAbs could potentially play a complementary role to effective vaccines.

“Nonetheless, the duration of protection from a mAb is expected to be shorter than that from vaccines. Also, since mAbs are currently administered as intravenous infusions, implementing wide-scale use may be logistically challenging. Overall, mAbs may not be the most cost-effective strategy for prophylaxis and hence would likely be shelved for vulnerable populations who don’t respond to vaccines or cannot take vaccines.”

Regeneron is testing a subcutaneous injection in a Phase III study focused on those who are household contacts of a COVID-19 patient. It has also outlined plans to study uninfected individuals at a high risk of exposure. The REGN10933 and REGN10987 cocktail is also in two Phase I/II/III trials in ambulatory and hospitalized patients, while LY-CoV555 is being evaluated in a Phase II ambulatory COVID-19 patient study and a Phase I trial in hospitalized patients.