Covid-19 treatment: A ray of hope before vaccine

The worldwide Covid-19 death toll has passed 1.3 million and it infected more than 50 million people. At this stage the world eagerly waits for an effective vaccine to defeat the Covid-19 pandemic. But till today no vaccine has been proved to be effective against coronavirus. Although the Corona vaccine has not been found to be effective till today, but the FDA has already approved "antibody therapy" for Corona treatment. On 9th November 2020, the Food and Drug Administration (FDA) has granted an emergency use authorization (EUA) for Eli Lilly's Covid-19 monoclonal antibody treatment, called Bamlanivimab.

Bamlanivimab is the first drug discovered during the Covid-19 pandemic to receive an EUA by FDA—every other treatment granted the status so far had been previously studied or approved for other diseases. "Bamlanivimab is a monoclonal antibody that is specifically directed against the spike protein of SARS-CoV-2, designed to block the coronavirus' attachment and entry into human cells. And monoclonal antibodies (mAbs) are laboratory-made proteins that mimic the immune system's ability to fight off harmful antigens such as viruses. " the FDA said in its statement.

The decision, announced by FDA, is likely to be a valuable tool to treat patients with Covid-19 at a time when the pandemic is raging across the globe. The chief scientific officer of Eli Lilly Dr. Daniel M. Skovronsky said, “It’s a great day for science and medicine — sort of a feat of what’s possible.” In a statement Alex M. Azar II, the health secretary and a former executive at Eli Lilly, said the FDA’s emergency authorization for Bamlanivimab is a “step forward” in “bridging us to the rollout of safe and effective vaccines.”

Monoclonal antibody treatments enjoyed a burst of publicity in October 2020, when US president Donald Trump received this type of treatment made by the US biotech company Regeneron and then enthusiastically promoted the drug. In a video released on October 7, Trump claimed without evidence that it was a “cure.” US Biotech Company Regeneron has also applied for emergency authorization with the FDA but that has not yet been approved.In monoclonal antibody therapy, artificial antibodies capable of resisting specific viruses (Covid 19) are made in the laboratory and applied to the human body by injection.

These drugs are laboratory-made versions of antibodies, blood proteins which when put into the body creates to help target and eliminate foreign infections. In this case as antibodies are introduced into the body from outside to increase the body's immune system, this method is also known as passive immunity.

Plasma therapy vs monoclonal antibody therapy
In Covid-19 treatment another well-known therapy is Plasma therapy. The principles of plasma therapy and monoclonal antibody therapy are more or less same. In plasma therapy, special antibodies are made in the body of a person by natural immunity who recovers after being infected with Covid-19 or coronavirus and then that antibodies are injected into the new patient's body through plasma. In monoclonal antibody therapy, special antibodies made artificially in the laboratory are injected into the patient's body. As plasma is not available to treat all the Covid-19 patients, and so the idea of modern monoclonal antibody therapy can fill this gap.

How monoclonal antibody (Bamlanivimab) works
Monoclonal antibody works directly on the Coronavirus to prevent it from replicating. Scientists have described three distinct phases of Covid-19 disease progression although there may be overlapping among the three phases of the disease. During the early infection phase (Phase 1), the coronavirus multiplies inside the body and is likely to cause mild symptoms that may be confused with a common cold or flu. During this period the virus growth is slow. The first phase takes a few days to a week following infection.

After the first phase the second phase starts, which is also known as pulmonary phase (Phase 2) and at this phase Coronavirus growth is rapid and the concentration of virus particles in nasal fluids, the lung, and the intestine is high. This is normally when patients begin to show symptoms, after the peak of virus replication.

After the second phase, the Covid patient enters the third or hyperinflammatory phase (Phase 3) and in this phase a hyperactivated immune system may cause injury to the heart, kidneys, and other organs of the infected patient. In this phase little to no infectious virus is present in the body but the disease the virus started with life-threatening symptoms continues.

The monoclonal antibodies for Covid-19 work only in the initial two phases (Phase 1 and Phase 2), usually before a patient is hospitalized. FDA said, Eli Lilly’s Bamlanivimab is authorized for the treatment of mild to moderate Covid-19 in adults and pediatric patients 12 years and older with a positive Covid-19 test, who are at high risk for progressing to severe Covid-19 and/or hospitalization. Bamlanivimab should be administered as soon as possible after a positive Covid-19 test and within 10 days of symptom onset.

FDA said, when administered to non-hospitalized patients as soon as possible after positive viral testing for SARSCoV-2 (Coronavirus) and within 10 days of symptom onset, Bamlanivimab may reduce viral load, symptoms, and risk of hospitalizations and emergency room visits associated with Covid-19. This means that the new drug Bamlanivimab need to be administered early enough to be effective, and an early positive result can lead to early treatment that might save a life.

Cost effectiveness of monoclonal antibody (Bamlanivimab) treatment
The main concern in the monoclonal antibody therapy is its cost of treatment. Antibody therapy costs more than vaccines. Again, antibody therapy may provide less protection than a vaccine. However, the main hope in the case of Covid-19 treatment is that antibody therapy protects the mild symptoms of the corona virus from becoming severe. But in the case of the serious condition of Covid-19, there is little hope of any significant help from such treatment. And so, experts say, this antibody treatment can be useful until an affordable corona vaccine is available.

Monoclonal antibody for other diseases

Since 1985, approximately 100 monoclonal antibodies (mAbs) have been designated as drugs and the rate of approvals by FDA is rapidly increasing. Available mAbs are used to treat HIV/AIDS, Asthma, Lupus, Ebola and several types of cancer. It is to be mentioned here that monoclonal antibodies (mAbs) have been a standard component of cancer therapy for the last 20 years.

Bamlanivimab for emergency treatment of Covid-19
Bamlanivimab has been given emergency use authorisation (EUA) by the US Food and Drug Administration (FDA) for treating mild to moderate Covid-19 in adults and children not admitted to hospital. Scientists are still testing Bamlanivimab in clinical trials to obtain full FDA approval. "We will continue to evaluate new data on the safety and efficacy of Bamlanivimab as they become available," Patrizia Cavazzoni, MD, acting director of the FDA's Center for Drug Evaluation and Research, said in the FDA statement.

But the U.S. government has already signed a $375 million deal with Eli Lilly this summer to supply some 300,000 vials (Each vial contains 700 mg) of the Bamlanivimab. The company will begin fulfilling those orders now that the FDA has given it the go-ahead. To ensure rapid access of this treatment to patients around the world, Eli Lilly has invested in large-scale manufacturing of Bamlanivimab.

Eli Lilly said it anticipated manufacturing up to one million doses of Bamlanivimab 700 mg by the end of 2020, for use worldwide through early next year. Beginning in the first quarter of 2021, Eli Lilly added, its supply of Bamlanivimab is expected to increase “substantially,” as additional manufacturing resources come online throughout the year.

It is to be mentioned here that only one drug — Gilead Sciences' Remdesivir — has full FDA approval for treating Covid-19. The drug Remdesivir is known to shorten the duration of hospital stay of some Covid-19 patients, but it is expensive and has its also shortcomings. Some other steroids, including dexamethasone, are also allowed for use in critically ill and hospitalized Covid-19 patients.

However, since the effectiveness of any vaccine against the coronavirus has not yet been fully confirmed, scientists are apparently relying on antibody treatment to coronavirus. They say the infused drugs (Bamlanivimab) could serve as a therapeutic bridge to help manage the coronavirus until vaccines are widely available.


The writer is a Pharmacist and  Doctoral Researcher of Massey University, New Zealand.