Billions Pouring Into Drugs That Could Treat Cancer Patients with High TROP2 Expressions
In the fight against some of the most challenging forms of cancer, AstraZeneca PLC (NYSE:AZN) recently placed a giant $6 billion bet on an antibody-drug conjugate (ADC) called DS-1062 from Japanese developers Daiichi Sankyo. The move signalled AZ’s confidence that this solid tumor drug could hit the same target as another approved ADC, known as Trodelvy from Immunomedics, Inc. (NASDAQ:IMMU). That target is trophoblast cell-surface antigen 2 (TROP2), a transmembrane protein overexpressed by tumors of the lung, breast, pancreas and other organs. Given the level of investment AstraZeneca has now committed to, a highlight is being shone on a segment of biotech companies tackling these forms of cancer through new drugs and drug combinations, including Oncolytics Biotech Inc. (NASDAQ:ONCY) (TSX:ONC), Merck & Co., Inc. (NYSE:MRK) and Pfizer Inc. (NYSE:PFE).
The potential for breakthroughs in these fields has Wall Street quite bullish. An example of a consensus on the sentiment comes when looking at Oncolytics Biotech Inc. (NASDAQ:ONCY) (TSX:ONC), which has earned an average rating from Wall Street analysts of Buy (3 Buy, 1 Hold, and no Sell ratings), and a significantly increased price projection over the next 12 months.
Optimism directed at the company is being credited to the milestones being met by its flagship platform, pelareorep, which promotes an anti-cancer response by inducing innate and adaptive immune responses creating a cancer immunotherapy that actively turns “COLD” tumors “HOT”.
Much like Daiichi Sankyo’s DS-1062, pelareorep is also being tested in combination with KEYTRUDA made by Merck & Co., Inc. (NYSE:MRK). However, the DS-1062/KEYTRUDA trial is for treating NCLC, while the pelareorep/KEYTRUDA is in Phase II of study to treat pancreatic cancer.
As well, both DS-1062 and pelareorep are being studied for treating triple-negative breast cancer (TNBC). This is significant, since high TROP2 expression has been reported in up to 80% of patients with TNBC.
Oncolytics recently kicked off its TNBC study, sponsored by New Jersey-based Rutgers Cancer Insitute (RCI), through a Phase 2 clinical trial to investigate the use of pelareorep and retifanlinmab, an anti-PD-1 checkpoint inhibitor. RCI will manage this clinical trial in patients with unsectable metastatic or locally advanced TNBC.
While also being in Phase 1 clinical development for treating non-small cell lung cancer (NSCLC), in July Daiichi Sankyo expanded its Phase 1 study for DS-1062 to include patients with advanced/unresectable or metastatic TNBC.
Should Daiichi (and now AstraZeneca) succeed with DS-1062, it won’t be the first drug targeting TROP2 to win FDA approval.
Immunomedics, Inc. (NASDAQ:IMMU) won that distinction in April, when the FDA authorized its lead ADC Trodelvy (sacituzumab govitecan-hziy) as a treatment for adults with metastatic TNBC who had at least received two prior therapies for metastatic disease. Trodelvy officially became the first ADC approved by the FDA specifically for relapsed or refractory metastatic TNBC, and is also the first FDA-approved anti-Trop-2 ADC.
The company recently reported encouraging early adoption of Trodelvy in the US, with $20.1 million in net sales during the first two months of launch.
BIG BETS BEING MADE
AstraZeneca’s (NYSE:AZN) recent deal with Daiichi Sankyo will have the pharma giant paying out $1 billion to co-develop an ADC called DS-1062 outside of Japan. The deal also features a further $5 billion in milestones, with the bet being made that it can hit the same target as Trodelvy.
Now the market’s hope is that platforms such as DS-1062 and others such as pelareorep can capitalize on similar successes as Trodelvy. It was results such as 33.3% of all patients that received Trodelvy experiencing a certain amount of shrinkage of their tumors that led to the drug’s approval.
Immunomedics, Inc. also recently announced that the FDA also approved Samsung Biologics to produce commercial-scale hRS7, the antibody used in Trodelvy, at its manufacturing facilities in Incheon, South Korea. The approval is said to enhance Immunomedics’ long-term supply of Trodelvy.
Previously, pharma giant Pfizer Inc. (NYSE:PFE) had also taken an anti-TROP2 ADC into the clinic but (according to Fierce Biotech) scrapped the trial after seeing early data, which left Trodelvy and DS-1062 as the front-runners. However, in late July, a partner of Pfizer announced that “very good progress” was being made on its own TNBC trial for a compound called ZEN-3694.
At the end of July, Merck & Co., Inc. announced two US regulatory milestones for its drug KEYTRUDA (pembrolizumab) in TNBC. First off the FDA granted priority review to KEYTRUDA’s Supplemental Biologics License Application (sBLA) when combined with chemotherapy for the treatment of certain patients with metastatic TNBC based on the Phase 3 KEYNOTE-355 trial. The FDA also accepted an sBLA for KEYTRUDA for the treatment of patients with high-risk early-stage TNBC based on the Phase 3 KEYNOTE-522 trial.
CURRENT PELAREOREP STUDIES
Back in June of 2019, Pfizer had signed a co-development agreement with both Oncolytics Biotech Inc. and Merck KGaA for what’s known as the BRACELET-1 study—(BReast cAnCEr with the Oncolytic Reovirus PeLareorEp in CombinaTion with anti- PD-L1 and Paclitaxel).
Though the BRACELET-1 study pertains to HR+ breast cancer, and not TNBC, there is much anticipation over its potential. Oncolytics has already announced that it has advanced its lead breast cancer program with the dosing of the first patient in the BRACELET-1 study.
The study will take place at 20 trial sites and enroll 45 patients randomized into three cohorts: one with just paclitaxel; one with paclitaxel + pelareorep; and a third with paclitaxel + pelareorep + avelumab (Merck and Pfizer’s shared immuno-oncology drug Bavencio®).
As stated above, pelareorep is also being studied for its potential in treating TNBC through a study dubbed “IRENE”. According to the available preclinical data, the drug shows potential in addressing the unmet needs in TNBC.
Clinical trial data suggests that the systematic administration of pelareorep shows promising outcomes in patients suffering from tumors in their breasts—helping to improve the patient count responding to what are known as checkpoint inhibitors.
Checkpoint investigators are used to target interactions between PD-1 and PD-L1. Commercially proven checkpoint investigators only achieve 20% success in patients with TNBC because of an ITM (immunosuppressive tumor microenvironment).
Throughout this study, RCI’s investigators will evaluate the efficacy and safety of pelareorep in TNBC patients in an anti-PD-1 combination cure. It will study the changes in the PD-L1 expression in this trial, along with peripheral T-Cell Clonality and correlations between the treatments’ outcomes.
The IRENE study is an open-label, single-arm, Phase 2 clinical trial investigating the use of INCMGA00012 and pelareorep to treat Metastatic TNBC or unresectable LA (locally advanced) TNBC. The drug combination is administered intravenously to the patients on the first, second, fifteen, and sixteenth day of the 28-day treatment program. Approximately 25 patients are enrolled for this clinical study at RCI.