The Antibody Society

the official website of the antibody society

An international non-profit supporting antibody-related research and development.

Antibody therapeutics for melanoma

by

May is Melanoma Awareness Month, with awareness campaigns kicking off on the first Monday (May 3rd in 2021). Melanoma is caused by cancerous melanocytes, which are cells in the epidermis that normally make a pigment, melanin, that protects other skin cells from damaging sun rays. The American Cancer Society (ACS) estimates the lifetime risk for developing the disease is ~ 2.6% (1 in 38) for whites, and 0.6% (1 in 167) for Hispanics, and 0.1% (1 in 1,000) for Blacks. Overall, melanoma is more common in men, and the risk of melanoma increases with age. The ACS’ data suggest that ~ 106,110 new melanomas will be diagnosed (~62,260 in men and 43,850 in women) and ~ 7,180 people may die of the disease in the United States during 2021.

Approved antibody therapies for melanoma

Three antibody therapeutics (ipilimumab, nivolumab, pembrolizumab)  that target the immune checkpoints CTLA-4 (CD152) or programmed cell death protein 1 (PD-1, CD279) are approved for melanoma.

  • YERVOY (ipilimumab), which targets cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), is indicated for the treatment of unresectable metastatic melanoma in adults and pediatric patients (12 years and older) and adjuvant treatment of patients with cutaneous melanoma with pathologic involvement of regional lymph nodes of more than 1 mm who have undergone complete resection, including total lymphadenectomy.
  • KEYTRUDA (pembrolizumab), which targets PD-1, is indicated for the treatment of patients with unresectable or metastatic melanoma, and for the adjuvant treatment of patients with melanoma with involvement of lymph node(s) following complete resection.
  • OPDIVO (nivolumab), which targets PD-1, is indicated for the treatment of patients with unresectable or metastatic melanoma and disease progression, including following ipilimumab and, if BRAF V600 mutation positive, a BRAF inhibitor, and for the adjuvant treatment of patients with melanoma with involvement of lymph node(s) following complete resection.

Combination therapy was shown to be superior to monotherapy with these checkpoint inhibitors in the Phase 3 Checkpoint study, which evaluated nivolumab monotherapy or nivolumab combined with ipilimumab versus ipilimumab monotherapy in patients with previously untreated unresectable or metastatic melanoma. The overall survival (OS) at 5 years was 52%, 44% and 26% in the nivolumab-plus-ipilimumab, nivolumab monotherapy, and ipilimumab monotherapy groups, respectively. However, Grade 3 or 4 treatment-related adverse events occurred more frequently in patients who received combination therapy (59%, 23%, and 28% of patients in the nivolumab-plus-ipilimumab, nivolumab, and ipilimumab treatment groups, respectively).

Investigational antibody therapies for melanoma

While the antibody therapeutics that target CTLA-4 and PD-1 have benefited melanoma patients, biopharmaceutical companies are developing novel antibody therapeutics that target other immune checkpoints such as LAG-3 or use different mechanisms of action.

  • Bristol-Myers Squibb is developing relatlimab (BMS-986016), which is a human IgG4 antibody targeting LAG-3 on T cells, thereby restoring effector function of exhausted T cells. Primary results from the Phase 2/3 RELATIVITY-047 (CA224-047) trial evaluating the fixed-dose combination of relatlimab and Opdivo (nivolumab) versus Opdivo alone in patients with previously untreated metastatic or unresectable melanoma indicated that the trial met its primary endpoint of progression-free survival.
  • Philogen  S.p.A. is developing Nidlegy, which is composed of two single-chain variable fragment (scFv)-based immunocytokines that target extra-domain B of fibronectin (L19IL2 + L19TNF combination), as neoadjuvant intralesional treatment for melanoma patients with locoregional disease. Two randomized, controlled Phase 3 registration trials for intralesional application of Nidlegy as a neoadjuvant followed by surgery + eventual adjuvant treatments (standard of care) and compared to standard of care are currently ongoing in Europe (PIVOTAL; NCT02938299) and in the USA (Neo-DREAM; NCT03567889) in patients with fully resectable stage IIIB/C melanoma.
  • Immunocore Ltd is developing tebentafusp, which comprises a high- affinity T cell receptor specific to a peptide sequence from the gp100 antigen, which is presented on melanoma tumor cells by HLA-A2, fused to an anti-CD3 single chain antibody fragment. In a Phase 3 study, tebentafusp demonstrated a statistically significant and clinically meaningful improvement in OS as a first-line treatment in metastatic uveal melanoma.  Tebentafusp has been granted Breakthrough Therapy Designation, Fast Track designation and orphan drug designation by the FDA and Promising Innovative Medicine designation under the UK Early Access to Medicines Scheme for metastatic uveal melanoma. Immunocore will be working with the FDA to complete submission of a BLA for tebentafusp in the third quarter of 2021.

The Antibody Society continuously collects data for antibody therapeutics in the commercial clinical pipeline. We will provide updates on the antibody therapeutics being evaluated for melanoma in future posts.

Need help keeping up to date on US and EU approvals?

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.

Loncastuximab tesirine granted first approval by FDA for large B-cell lymphoma

by

On April 23, 2021, the  US Food and Drug Administration (FDA) granted accelerated approval to loncastuximab tesirine-lpyl (Zynlonta, ADC Therapeutics SA) for adult patients with relapsed or refractory large B-cell lymphoma after two or more lines of systemic therapy, including diffuse large B-cell lymphoma (DLBCL) not otherwise specified, DLBCL arising from low grade lymphoma, and high-grade B-cell lymphoma. This marketing application was granted priority review and orphan drug designation by FDA. The review used the Assessment Aid, a voluntary submission from the applicant to facilitate the FDA’s assessment.

Loncastuximab tesirine (ADCT-042) is an antibody-drug conjugate composed of an anti-CD19 humanized IgG1k antibody conjugated via a linker to pyrrolobenzodiazepine-dimer toxin that induces the killing of CD19-expressing malignant B cells.

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 intravenous 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 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.

Need help keeping up to date on US and EU approvals?

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.

Dostarlimab approved by FDA for endometrial cancer

by

On April 22, 2021, the U.S. Food and Drug Administration (FDA) granted accelerated approval to Jemperli (dostarlimab) for treating patients with recurrent or advanced endometrial cancer that has progressed on or following prior treatment with a platinum-containing chemotherapy and whose cancers are deficient in their ability to repair DNA inside the cell, as determined by an FDA-approved test. FDA granted dostarlimab Priority Review and Breakthrough Therapy designations for this indication. Dostarlimab (TS-042, GSK4057190A) is an anti-PD-1 humanized IgG4k antibody generated by Anaptysbio under partnership with Tesaro, which was acquired by GlaxoSmithKline in 2019.

Interim analyses of data for patients with mismatch repair (MMR)-deficient endometrial cancer with recurrent or advanced disease that progressed on a platinum doublet regimen enrolled in the Phase 1 GARNET study (NCT02715284) were reported at the European Society for Medical Oncology (ESMO) Virtual Congress in September 2020. Patients received 500 mg of dostarlimab every 3 weeks for the first 4 cycles, then 1,000 mg every 6 weeks until disease progression or discontinuation. The primary endpoints included confirmed objective response rate (ORR) and duration of response (DOR). The ORR was 44.7% in patients with deficient mismatch repair (dMMR) disease and 13.4% in those with MMR-proficient (MMRp) disease. In the dMMR cohort (n = 103), 11 complete responses, and 35 partial responses were observed. Thirteen patients achieved stable disease, while 39 patients experienced disease progression. In the MMRp cohort (n = 142), 3 patients had complete responses, 16 had partial responses, 31 achieved stable disease, and 77 patients experienced progressive disease. At the time of data cutoff, with a median follow up of 11.2 months, the median DOR had not been reached.

Dostarlimab is also being evaluated as a treatment for various types of cancer in early-stage clinical studies, as well as two Phase 3 studies, RUBY and FIRST. The RUBY study (NCT03981796) is evaluating dostarlimab plus carboplatin-paclitaxel versus placebo plus carboplatin-paclitaxel in patients with recurrent or primary advanced endometrial cancer. The primary outcome measure is the progression-free survival (PFS) assessed by an investigator, and the primary completion date is July 2021. The FIRST study (NCT03602859) is a comparison of platinum-based therapy with dostarlimab and niraparib versus standard of care platinum-based therapy as first-line treatment of Stage III or IV non-mucinous epithelial ovarian cancer. The primary outcome measure is the PFS and the primary completion date is January 2023.

Need help keeping up to date on US and EU approvals?

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.

Science Writing Competition

by

Attention Student & Post-doc members:
Our Science Writing Competition is now open!
Submission deadline: July 1, 2021

Clear, concise communication is essential to make your science accessible! The Antibody Society is offering you a chance to grow this skill through a Science Writing Competition.

We invite you to submit an essay of 1200 – 1500 words on a topic related to antibody research. Feel free to use an eye-catching self-generated high-resolution graphic (jpg format) to help make your main point. Relevant topics include, but are not limited to:

  • Antibody engineering
  • Antibody therapeutics
  • Fc effector function and neutralization
  • Bispecific antibodies
  • Antibody-drug conjugates
  • Adaptive immune receptor repertoires

The winning essays will be featured on The Antibody Society’s website, and winners will be offered an opportunity to give a short talk on their essay topic in a Society webcast. Winners will also receive free registration to one meeting we co-promote, as listed on our Upcoming Meetings page, or one of the following meetings that we organize:

Two winners (1 student, 1 post-doc) will be selected by our panel of judges based on the originality, creativity, clarity, and structure of their essays.

Submission deadline: July 1, 2021

Winners will be announced by July 9, 2021.

Entry is limited to The Antibody Society student and post-doc members. Submission details and the competition rules are found here.

Not a member? Click here to register for your free membership!

Searching for alternatives in anti-EGFR-based therapies: New uses for antibody 528

by

Post by Raquel Barroso Ferro, University of Aberdeen

Epidermal growth factor receptor (EGFR) is a well known and validated target for monoclonal antibody (mAb) therapeutics. Three anti-EGFR antibodies are currently marketed, cetuximab, necitumumab, and panitumumab. Cetuximab, a recombinant chimeric (human-mouse) monoclonal antibody (mAb) was the first approved, in February 2004, for treatment of colorectal cancer in patients who failed to respond to irinotecan-based chemotherapy. [1] By binding to EGFR with high affinity, the anti-EGFR antibodies prevent EGF, the ligand to EGFR, binding, and therefore block receptor activation and subsequent pro-survival and proliferation-associated signaling pathways. Therefore, in tumors that depend on this receptor to grow, blocking EFGR can halt tumor progression. This is critical, as patients whose tumors had elevated levels of EGFR/EGF were more likely to have aggressive disease, and therefore a poorer prognosis. [2]

Patients commonly become resistant to anti-EGFR antibody therapies through mutational escape. Cetuximab, necitumumab, and panitumumab bind relatively close epitopes and even share epitope regions on EGFR domain III. [3-5] Whilst a mutation in EGFR can make tumors resistant to one antibody but still susceptible to the remaining two such as in the case of S492R that blocks cetuximab binding but panitumumab remains able [5], there are many mutations that can block a tumor’s susceptibility to all three antibodies simultaneously. [6]

Another anti-EGFR mAb, derived from mouse and known as 528, was first reported in the early 1980s. [7,8] Makabe and colleagues [9] recently reported that, while 528 also binds EGFR domain III, its epitope includes a loop formed by residues 353–362 that is not part of the binding sites of cetuximab, necitumumab, and panitumumab. Thus, tumors that are resistant to all three of the currently available antibodies could in theory be susceptible to 528. Although additional studies are required to accurately deduce the interaction of EGFR and 528, compare 528 to the existing therapies, and assess the effects of various EGFR mutations, these initial findings by Makabe and colleagues are intriguing and represent a worthwhile avenue to explore.

Scientists have also investigated 528’s anti-EGFR binding capabilities in bispecific formats that may have therapeutic potential. Humanized versions of 528’s variable region and the anti-CD3 variable region derived from OKT-3, an immunosuppressant drug, were used to construct a bispecific molecule, hEx3, with the aim of bridging T cells to EGFR on cancer cells, thereby targeting the cancer cells for destruction. [10] This bispecific construct was shown to form functional tetramers. [11] The cytotoxicity of hEx3 could be enhancement by affinity maturation [12], by rearranging the variable domain order [13, 14] and by generating Fc fusions. [14, 15 Taken together, the findings of these studies are intriguing. The simple rearrangement of the heavy and light domains from heavy-light to light-heavy substantially enhanced the cytotoxic anti-tumor activity of the hEx3 diabody, as did the introduction of a LH-HY52W mutation hypothesised to increasing affinity of the 528 variable region and its target, EGFR. Moreover, the engineered molecules had enhanced anti-tumour killing in vivo. [15] This result may be associated with increased valency or perhaps through the reduction of serum clearance, which is currently an obstacle to use of non-native, truncated antibody formats. [16]

Overall, anti-EGFR based antibody therapeutics utilizing 528’s epitope-binding region may present new avenues of attack due to its distanced binding site compared to existing therapies. Importantly, nuanced changes to antibody structures, including simple domain rearrangements and alteration of the amino acid sequence, could translate into substantial changes to efficacy.

References
1.       Wong, SF. (2005). Cetuximab: an epidermal growth factor receptor monoclonal antibody for the treatment of colorectal cancer. Clin Ther. 47(6): 684-694.
2.       Chen J, et al. Expression and function of the epidermal growth factor receptor in physiology and disease. Physiol Rev. 2016. PMID: 33003261.
3.       Li, S. et al. (2005). Structural basis for inhibition of the epidermal growth factor receptor by cetuximab. Cancer. Cell. 7; 301–311.
4.       Bagchi, A. et al. (2018). Molecular basis for necitumumab inhibition of EGFR variants associated with acquired cetuximab resistance. Mol. Cancer. Ther. 17; 521–531. DOI: 10.1158/1535-7163.MCT-17-0575.
5.       Sickmier, E. A. et al. (2016). The panitumumab EGFR complex reveals a binding mechanism that overcomes cetuximab induced resistance. PLoS ONE 11, e0163366. DOI: 10.1371/journal.pone.0163366.
6.       Arena, S. et al. (2015). Emergence of multiple EGFR extracellular mutations during cetuximab treatment in colorectal cancer. Clin. Cancer Res. 21; 2157–2166. DOI: 10.1158/1078-0432.CCR-14-2821.
7.       Kawamoto et al. (1983). Growth stimulation of A431 cells by epidermal growth factor: identification of high-affinity receptors for epidermal growth factor by an anti-receptor monoclonal antibody. PNAS. 80 (5) 1337-1341.
8.       Gill GN, et al. Monoclonal anti-epidermal growth factor receptor antibodies which are inhibitors of epidermal growth factor binding and antagonists of epidermal growth factor binding and antagonists of epidermal growth factor-stimulated tyrosine protein kinase activity. J. Biol. Chem. 1984;259:7755–7760. doi: 10.1016/S0021-9258(17)42857-2.
9.       Makabe et al. (2021). Anti-EGFR antibody 528 binds to domain III of EGFR at a site shifted from the cetuximab epitope. Sci. Rep. 11: 5790.
10.   Asano et al. (2006). Humanization of the bispecific epidermal growth factor receptor × CD3 diabody and its efficacy as a potential clinical reagent. Clin Cancer Res. 12(13). DOI: 10.1158/1078-0432.CCR-06-0059.
11.   Asano et al. (2010). Highly enhanced cytotoxicity of a dimeric bispecific diabody, the hEx3 tetrabody. J. Biol. Chem. 285(27); 20844-20849.
12.   Nakanishi, T. et al. (2013) Development of an affinity-matured humanized anti-epidermal growth factor receptor antibody for cancer immunotherapy. Protein Eng. Des. Sel. 26, 113–122.
13.   Asano et al. (2013). Domain order of a bispecific diabody dramatically enhances its antitumor activity beyond structural format conversion: The case of the hEx3 diabody. Prot. Eng. Des. Sel. 26(5): 359-367.
14.   Asano, R. et al. (2014) Rearranging the domain order of a diabody-based IgG-like bispecific antibody enhances its antitumor activity and improves its degradation resistance and pharmacokinetics. MAbs 6, 1243–1254.
15.   Asano et al. (2020). Build-up functionalization of anti-EGFR × anti-CD3 bispecific diabodies by integrating high-affinity mutants and functional molecular formats. Sci. Rep. 10; 4913.
16.   Wu et al. (1996).  Tumor localization of anti-CEA single-chain Fvs: improved targeting by non-covalent dimers. Immunotechnology. 2(1): 21-36. DOI: 10.1016/1380-2933(95)00027-5.