Moving up with the monoclonals

Monoclonal antibodies (mAbs) continue to dominate the pharmaceutical market. Last year, total global sales of mAbs were over $122 billion, and sales are expected to rise to more than $200 billion in 2024 (Fig. 1). Seven of the top ten best-selling drugs in 2018 were mAbs, with Humira (adalimumab)—AbbVie’s multibillion blockbuster therapy for various immune disorders—in the top spot with sales of $20 billion (Nat. Rev. Drug Discov. 18, 245; 2019). In this feature, we explore the current and forecasted mAb market with the help of Evaluate Ltd.

Core strengths

Since the pioneering mAb approval in 1986, mAbs have matured to become a core therapeutic modality, with more than 80 mAbs now approved for a wide range of diseases.

Two areas have historically seen particular success for therapeutic mAbs. One is oncology, for which total sales of mAbs were around $50 billion in 2018 (Fig. 2). Here, mAbs that target cancer cell signaling, such as Roche’s human epidermal growth factor receptor 2 (HER2)specific mAb Herceptin (trastuzumab) for breast cancer and its vascular endothelial growth factorspecific mAb Avastin (bevacizumab) for various cancers, have had many years of commercial success. Both products had sales of more than $5 billion in 2018 (Fig. 3). Two more recent entrants into the bestselling mAbs list are also oncology products: Merck and Co.’s Keytruda (pembrolizumab) and Bristol-Myers Squibb’s Opvido (nivolumab), which both had sales greater than $5 billion in 2018 too. These mAbs inhibit the immune checkpoint programmed cell death 1, and have been at the forefront of the cancer immunotherapy revolution (see the feature).

The other highly successful area for mAbs is products that target signaling by inflammatory cytokines such as tumor necrosis factor (TNF) to treat immune disorders. Humira is one of several TNF blockers that have achieved blockbuster status, based on approvals for multiple indications, including rheumatoid arthritis, psoriasis, Crohn’s disease and ankylosing spondylitis. Remicade (infliximab), Johnson & Johnson’s TNF blocker, is indicated for a similarly wide range of immune disorders, and was still in the top tenselling mAbs in 2018 (Fig. 3) despite growing competition from biosimilar versions. Stelara (ustekinumab), another mAb marketed by Johnson and Johnson that is just ahead in the top ten, targets the interleukins IL12 and IL23 to treat diseases including Crohn’s disease, psoriasis and psoriatic arthritis, while Novartis’s Cosentyx (secukinumab), an IL17 blocker that is approved for psoriasis, psoriatic arthritis and ankylosing spondylitis, also makes the list.

Evolution of the top ten

In 2018, AbbVie’s Humira topped the top ten list of bestselling mAbs by a wide margin, outselling the secondplaced Keytruda by more than $10 billion (Fig. 3). However, substantial changes to this list are forecasted by 2024, as more of the established products lose patent protection and biosimilar competitors enter the market (Fig. 4). For Humira, such competitors are not expected until 2023, meaning that it is forecasted to be in second place in 2024. However, products with nearerterm or existing biosimilar competition, such as Remicade, Herceptin, Avastin and Rituxan (rituximab), are set to fall out of the top ten completely (Fig. 4) .

Humira is forecasted to be replaced at the top of the list by Keytruda, with its sales of more than $15 billion in 2024 reflecting its position as a backbone of cancer immunotherapy strategies in multiple indications. Its competitor Opdivo is also in the top three, but the gap in sales compared with Keytruda is widening, reflecting the greater success of Keytruda in indications such as nonsmallcell lung cancer.

New entrants into the top ten in 2024 include Ocrevus (ocrelizumab) developed by Roche (Genentech) for the treatment of multiple sclerosis. The CD20targeted mAb, which is the first drug to be approved for both relapsing–remitting and primary progressive multiple sclerosis, has had one of the most successful launches ever, reaching blockbuster status only a year after its approval in 2017 (Nat. Rev. Drug Discov. 17, 855; 2018). Roche also has another entrant, Perjeta (pertuzumab), a HER2targeted mAb for the treatment of breast cancer. Sales from these two products could help the company compensate for the loss of revenue from its current leading mAbs Herceptin, Avastin and Rituxan due to biosimilar competition. Two other new entrants that are forecast to enter the top 10 are for immunoinflammatory disorders. Dupixent (dupilumab), developed by Regeneron and Sanofi, is an inhibitor of IL4 and IL13 that is approved for atopic dermatitis and asthma, while Takeda’s Entyvio (vedolizumab), which targets the integrin α4β7, is approved for Crohn’s disease and ulcerative colitis.

Completing the top ten, Johnson & Johnson’s Darzalex (daratumumab) is a CD38targeted mAb that is approved for multiple myeloma. Together with other leading anticancer mAbs, such as Keytruda, Opdivo and Perjeta, it will contribute to the expansion of the overall market for mAbs in oncology to $88 billion in 2024 (Fig. 2).

New approvals

In a recordbreaking year for US Food and Drug Administration approvals, 2018 saw the approval of 11 mAbs (Table 1), representing almost 20% of the total of 57 newly approved drugs (Nat. Rev. Drug Discov. 15, 85–89; 2019). Unusually, many of the new approvals occurred in areas outside of oncology. For example, Trogarzo (ibalizumab), developed by TaiMed Biologics and Theratechnologies, is a CD4targeted mAb that is the first biologic to be approved for the treatment of HIV. Given the dominance of smallmolecule combination therapies in this area though, it is not predicted to be a blockbuster.

The entry of multiple mAbs in the central nervous system area is expected to lead to greater commercial success. Amgen and Novartis were the first to gain approval for a mAb that blocks signaling by calcitonin generelated peptide (CGRP) to treat migraine with the approval of Aimovig (erenumab), which targets the CGRP receptor.

Shortly after, Eli Lilly and Teva had their competitor mAbs—Ajovy (fremanezumab) and Emgality (galcenzumab)—also approved for migraine. Both target CGRP, rather than the CGRP receptor. How differences between these products will play out in the market is not yet clear, but all three mAbs were forecasted at launch to be close to or beyond blockbuster status by 2024.

Finally, there were notable mAb approvals for rare diseases, such as Ultragenyx’s Crysvita (burosumab), which targets fibroblast growth factor 23 to treat Xlinked hypophosphatemia, and Alexion Pharmaceuticals’Ultomiris (ravulizumab), which targets complement C5 to treat paroxysmal nocturnal hemoglobinuria. Both are expected to become blockbusters.