Food and Drug Administration Archives

FDA approves Inmazeb for Ebola virus infection

October 15, 2020 by Janice Reichert

On October 14, 2020, FDA approved the triple antibody cocktail of atoltivimab, maftivimab, and odesivimab-ebgn (Inmazeb) for the treatment for Zaire ebolavirus (Ebola virus) infection in adult and pediatric patients. Atoltivimab, maftivimab, and odesivimab are IgG1 antibodies that bind glycoprotein on the surface of Ebola virus, thereby blocking attachment and entry of the virus into cells. FDA granted the atoltivimab, maftivimab, and odesivimab cocktail Breakthrough Therapy and Orphan Drug designations for the approved indication. Inmazeb was developed by Regeneron.

The effects of Inmazeb were evaluated in adult and pediatric patients with confirmed infections that occurred during an Ebola virus outbreak in the Democratic Republic of the Congo in 2018 and 2019. In the Pamoja Tulinde Maisha (PALM) study (NCT03719586), a 4-arm trial evaluating investigational therapies for Ebola virus infection initiated in November 2018, 154 patients received Inmazeb as a single IV infusion of 50 mg of each monoclonal antibody. The primary efficacy endpoint was 28-day mortality. At this timepoint, 33% of those who received Inmazeb had died vs 51% of those who received a control. Inmazeb was also made available in an expanded access program, which included an additional 228 patients who received Inmazeb. The PALM study was sponsored by the US National Institute of Allergy and Infectious Diseases, with collaborators from Institut National de Recherche Biomédicale (Democratic Republic of Congo); the Alliance for International Medical Action (Senegal); International Medical Corps, Los Angeles (US); Epicentre, Médecins sans Frontières, (France); and the World Health Organization (Switzerland).

Inmazeb is the 9th antibody therapeutic to be granted a first approval in the US or EU in 2020.

The Antibody Society maintains a comprehensive table of approved monoclonal antibody therapeutics and those in regulatory review in the EU or US. The table, which is located in the Web Resources section of the Society’s website, can be downloaded in Excel format.

Emergency use authorization requests for anti-SARS-CoV-2 antibodies under FDA review

October 12, 2020 by Janice Reichert

On October 7, 2020, Eli Lilly and Company and Regeneron announced that they have submitted requests to the U.S. Food and Drug Administration (FDA) for emergency use authorizations (EUA) of their anti-SARS-CoV-2 monoclonal antibodies.

Lilly’s EUA request is for bamlanivimab (LY-CoV555) monotherapy in higher-risk patients who have been recently diagnosed with mild-to-moderate COVID-19. According to the company, up to 100,000 doses of 700 mg LY-CoV555 monotherapy may be available in October, and one million doses available in Q4 2020.

The combination of LY-CoV555 and LY-CoV016, which bind complementary regions of the SARS-CoV-2 spike protein, for the treatment of symptomatic COVID-19 in an outpatient setting is also being evaluated. Lilly anticipates submission of an EUA request for combination therapy in November, and may have data to support a biologics license application submission for combination therapy as early as Q2 2021.

Regeneron’s EUA request is for REGN-COV2, which is a combination of two anti-SARS-CoV-2 monoclonal antibodies (REGN10933 and REGN10987). Regeneron was granted a $450 million contract to manufacture and supply REGN-COV2 by the US government, which has committed to making the doses available to Americans for free. The agreement covers a fixed number of bulk lots that are intended to be completed in the fall of 2020, as well as fill/finish and storage activities. At the time of the EUA request, Regeneron had doses available for ~ 50,000 patients, and expects to have doses available for a total of 300,000 patients within several months.

The Antibody Society is tracking the progress of recombinant biologic COVID-19 interventions in preclinical and clinical studies. Summary data for all anti-SARS-CoV-2 antibodies in clinical studies can be found here.

Two new antibody therapeutics enter FDA review

September 22, 2020 by Janice Reichert

The first biologics license applications (BLAs) for two antibody therapeutics, balstilimab (AGEN2034) and loncastuximab tesirine (ADCT-042), have recently been submitted to the US Food and Drug Administration, bringing the total number of antibody therapeutics undergoing a first review to 18 (see table here for details).

Balstilimab (Agenus Inc.)

Balstilimab (AGEN2034) is a human IgG4k antibody directed against PD-1, a negative regulator of immune activation expressed by T cells. Numerous antibodies that target PD-1 or its ligand PD-L1 (e.g., pembrolizumab, nivolumab, cemiplimab, avelumab, durvalumab) are marketed as treatments for solid tumors as well as lymphoma. Agenus’ clinical studies of balstilimab have focused on its use, either as monotherapy or in combination with anti-CTLA4 zalifrelimab (AGEN1884), as a treatment for cervical cancer. FDA granted both balstilimab and the balstilimab/ zalifrelimab combination Fast Track designations for the treatment of cervical cancer. On September 18, 2020, Agenus Inc. announced that they had initiated a rolling BLA to FDA for balstilimab as monotherapy for the treatment of recurrent/metastatic cervical cancer. Agenus controls worldwide rights to balstilimab, except for certain South American rights, which are controlled by Recepta Biopharma, and Greater China rights, which are exclusively licensed to Betta Pharmaceuticals.

Data from a randomized, blinded, non-comparative, two-arm Phase 2 study (NCT03894215) supported the BLA submission. This study evaluated the efficacy and safety of balstilimab as monotherapy or in combination with zalifrelimab for treatment of patients with advanced cervical cancer who relapsed or progressed after receiving first-line platinum-based chemotherapy for a maximum of 24 months, or until disease progression or unacceptable toxicity. The goal of the study is to evaluate the efficacy of each arm against its relevant historical controls. The primary outcome measure is the objective response rate (ORR) to balstilimab administered with placebo (Treatment Arm 1 – monotherapy), or with zalifrelimab (Treatment Arm 2 – combination therapy). Data from the study were presented at the 2020 European Society for Medical Oncology Virtual Congress. Of 160 patients included in the balstilimab monotherapy arm, the ORRs in PD-L1-positive patients and all patients were 19% and 14%, respectively. Of 143 patients included in the balstilimab/ zalifrelimab combination arm, the ORRs in PD-L1-positive patients and all patients were 27% and 22%, respectively.

Loncastuximab tesirine (ADC Therapeutics SA)

Loncastuximab tesirine (ADCT-042) is an ADC composed of an anti-CD19 humanized IgG1k antibody conjugated via a linker to pyrrolobenzodiazepine (PBD)-dimer toxin that induces the killing of CD19-expressing malignant B cells. The FDA granted Orphan Drug designation to ADCT-402 for the treatment of diffuse large B-cell lymphoma (DLBCL) and mantle cell lymphoma. On September 21, 2020, ADC Therapeutics SA announced the submission of a BLA to FDA for loncastuximab tesirine for the treatment of patients with relapsed or refractory DLBCL.

The BLA submission was supported by data from the open-label, single-arm Phase 2 LOTIS 2 study (NCT03589469), which evaluated the safety and efficacy of loncastuximab tesirine for the treatment of patients with relapsed or refractory DLBCL following ≥2 lines of prior systemic therapy. A total of 145 patients received loncastuximab tesirine as an IV infusion over 30 minutes on Day 1 of each cycle (every 3 weeks) at a dose of 150 μg/kg for 2 cycles, then 75 μg/kg for subsequent cycles for up to one year or until disease progression, unacceptable toxicity, or other discontinuation criteria. The primary outcome measure is the overall response rate (ORR). Positive initial data from LOTIS 2 were presented during the virtual 25th Annual Congress of the European Hematology Association. The ORR was 48.3% (70/145 patients), the complete response rate (CRR) was 24.1% (35/145 patients), and the median duration of response was 10.25 months. The toxicity profile was manageable and no new safety concerns were identified.

Antibodies to Watch in a Pandemic

August 26, 2020 by The Antibody Society

The extraordinary scale of the COVID-19 pandemic has elicited extraordinary responses world-wide, but the resulting disruptions have raised concerns about delays in approval of non-COVID-19 antibody therapeutics.

As part of the virtual Antibody Engineering & Therapeutics Europe conference, Dr. Janice Reichert, Executive Director of The Antibody Society, provided an update on non-COVID-19 antibody therapeutics approved so far in 2020, and those that might be approved by the end of the year. She also discussed the biologics currently in development for COVID-19, which includes over 50 repurposed biologics and over 80 anti-SARS-CoV-2 biologics.

Broadcast date: Thursday August 27, 2020.

Updated presentation slides can be downloaded here.

Dataset of commercially sponsored biologic COVID-19 interventions can be downloaded here.

FDA issues Emergency Use Authorization for COVID-19 convalescent plasma

August 24, 2020 by Janice Reichert

On August 23, 2020, the U.S. Food and Drug Administration (FDA) issued an emergency use authorization (EUA) for investigational COVID-19 convalescent plasma (CCP) for the treatment of COVID-19 in hospitalized patients. CCP is human plasma collected by FDA-registered blood establishments from individuals whose plasma contains anti SARS-CoV-2 antibodies, and who meet all donor eligibility requirements and are qualified. Titer levels of anti-SARS-CoV-2 antibodies are determined by the Ortho VITROS SARS-CoV-2 IgG test before units of CCP are released. Units found to have a signal-to-cutoff ratio of 12 or greater qualify as High Titer COVID-19 Convalescent Plasma.

Based on scientific evidence available, the FDA concluded CCP may be effective in treating COVID-19, and that the known and potential benefits of CCP outweigh the known and potential risks of the product. The EUA authorizes the distribution of COVID-19 convalescent plasma in the U.S. and its administration by health care providers, as appropriate, to treat suspected or laboratory-confirmed COVID-19 in hospitalized patients with COVID-19.

Data obtained from the ongoing National Convalescent Plasma Expanded Access Protocol (EAP) sponsored by the Mayo Clinic was included in FDA assessment. This uncontrolled, single-arm study was established in April 2020 to provide access to COVID-19 convalescent plasma in hospitalized subjects with severe or life-threatening COVID-19 or judged by the treating provider to be at high risk of progression to severe or life-threatening disease. As of August 13, 2020, over 90,000 patients have been enrolled. Data from the EAP posted online on August 12, 2020 reveals trends toward reduced mortality when patients receive CCP with higher antibody levels and at earlier time points. According to FDA’s decision memorandum:

In the subset of non-intubated patients, there was a 21% reduction in 7-day mortality (from 14% to 11%, p=0.03) in subjects transfused with high versus low titer CCP.
In the subgroup of patients less than 80 years of age who were not intubated and who were within 72 hours of diagnosis, a significant reduction in 7-day mortality from 11.3 to 6.3% (p = 0.0008) was observed when titers are binned to low versus high.
Survival trends observed at 7 days persisted over a longer time period, with significantly improved survival in non-intubated patients (p=0.032) and a larger benefit in the subset of patients not intubated at the time of treatment, less than 80 years of age, who were treated within 72 hours of diagnosis (p=0.0081)

However, there was no difference in 7-day survival in the overall population between subjects transfused with high versus low titer CCP, and there was no apparent association between neutralizing antibody titers and 7-day mortality in intubated subjects.

Information from the EUA and clinical studies of CCP may inform the development of other biologic COVID-19 interventions, such as recombinant anti-SARS-CoV-2 antibodies. The Antibody Society is currently tracking 10 such antibodies in clinical studies or with clinical studies pending. We will report on the progress of these molecules and other COVID-19 interventions in the future.