TG Therapeutics (TGTX -1.50%) shares have been on a roll since positive data from cancer trials was presented at the annual American Society of Clinical Oncology (ASCO) conference earlier this month. This week, the company's adding to its good news with updated data for a triplet cancer regimen being presented at the International Conference on Malignant Lymphoma.
Producing precision medicine
At ASCO, TG Therapeutics said that adding its TG-1101, or ublituximab, to AbbVie Inc.'s (ABBV 1.06%) top-selling Imbruvica resulted in an objective response rate (ORR) of 78% in patients with high-risk chronic lymphocytic leukemia. The complete response rate to the two-drug combination was 7%.
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Those results match up favorably with Imbruvica monotherapy. In the trial, the ORR and complete response rates for Imbruvica on its own were 45% and 0%, respectively.
Ublituximab is a monoclonal antibody designed to inhibit CD-20, and that makes it one of many drugs being developed by biotech companies eager to improve patient outcomes by focusing on specific genetic or molecular characteristics.
CD-20 is a type of protein that's found on a type of white blood cell called B-cells. It plays a role in optimizing a patient's immune response, and it can be highly expressed in patients with certain forms of lymphoma and leukemia.
Inhibiting CD-20 activity has already been proven to help patients with blood cancers. For example, it's the target of the top-selling cancer drug Rituxan. However, ublituximab is different from these drugs because it targets a specific and unique CD-20 molecule that's found on mature B-cells.
In cancer patients with high-risk mutations, such as 17p deletion, 11q deletion, and p53 mutation, the use of TG-1101 alongside Imbruvica, which targets a different protein, appears to be quite effective.
Another win
At the International Conference on Malignant Lymphoma, TG Therapeutics is rolling out data showing that a three-drug combination of ublituximab with its drug TGR-1202 and the chemotherapy drug bendamustine may improve outcomes in patients with non-Hodgkin lymphoma.
In a small group of patients with relapsing diffuse large B-cell lymphoma (DLBCL), the three-drug mash-up delivered an ORR of 100%. The ORR among DLBCL patients with chemorefractory and/or SCT-refractory DLBCL was 50%. And it was 88% in patients with relapsing or refractory follicular lymphoma.
What's intriguing is that TGR-1202 is a PI3K delta inhibitor like Gilead Sciences' (GILD 0.91%) Zydelig, yet safety concerns that have derailed Zydelig's commercial sales might not be a problem for TGR-1202 -- at least not yet. TG Therapeutics says that in this trial, the three-drug combination "was very well tolerated, with a low incidence of Grade 3 or greater adverse events, particularly those that have been associated with the PI3K-delta class."
If efficacy and safety stay this good in a planned registrational study, then TGR-1202 could eventually generate sales in nine figures. For perspective, despite safety concerns, Zydelig's first-quarter sales were still $35 million.
Looking ahead
TG Therapeutics still has more work to do before it can present any data to regulators for an eventual approval of these drugs, but the results are encouraging, and the company's focus on late-line, precision therapies where there's an important need for new treatments could give it an edge in securing an accelerated review from the U.S. Food and Drug Administration.
If so, then the market potential could be significant enough to support further upside. TG Therapeutics thinks ublituximab's market potential exceeds $200 million annually, and that its opportunity in DLBCL could be $1 billion plus. Given that the company's market cap values it at less than $750 million right now, an argument can be made that there's still running room for its shares to go higher.
