New data from an ongoing Phase 1/2 clinical trial has revealed an experimental immunotherapy led to successful response rates in 73% of patients suffering from multiple myeloma, a deadly form of blood cancer. Based on this promising data, an application to the US Food and Drug Administration (FDA) has been filed to bring the drug to market.
The immunotherapy being trialled is called talquetamab. Known as a bispecific T-cell engager antibody, this treatment is a relatively new kind of immunotherapy approach.
Unlike traditional monoclonal antibodies, bispecific antibodies are engineered to bind to two different antigens. In this instance, talquetamab binds to CD3, a receptor on immune T cells, and GPRC5D, a receptor found in high levels on cancerous plasma cells.
The idea behind bispecific antibodies is they work to bridge immune cells with cancer cells. They simultaneously plant a target flag on cancer cells and give immune cells a roadmap to that target.
The technology has been in development for decades but it has only been in the last few years that bispecific antibodies have finally reached clinical uses. There are currently three FDA-approved bispecfiic antibody therapies on the market (primarily targeting cancers), and more than 100 prospective antibodies in clinical trials (aimed at everything from Alzheimer's to diabetes).
The recently announced Phase 1/2 talquetamab trial data covered several hundred multiple myeloma patients, spanning two different doses and either weekly or fortnightly dosing schedules. Overall, across all treatment groups the trial found 73% of subjects responded positively to the treatment.
"With a median follow-up of 14.9 months (range 0.5+ to 29.0), 74.1 percent of patients treated at the SC [subcutaneous] 0.4 mg/kg dose administered weekly achieved a response, 59.4 percent achieved a very good partial response or better, 33.6 percent achieved a complete response or better and 23.8 percent achieved a stringent complete response," reported pharmaceutical company Johnson & Johnson in a press release.
The Phase 2 trial data has yet to be formally published in a peer-reviewed journal, however, the Phase 1 data has just been published in The New England Journal of Medicine. That data has revealed most patients treated with talquetamab experienced mild side effects, but only around five percent had to cease treatment due to those adverse effects.
Earlier in 2022, based on preliminary positive trial data, the FDA granted talquetamab Breakthrough Therapy designation. This allowed the treatment priority and accelerated pathways through approval processes. A Biologics License Application has now been filed with the FDA as the company looks to bringing this novel drug to market as soon as possible.
“Following our recent Biologics License Application submission to the US FDA, we look forward to working with the agency to make this available as a treatment option in the short term and continuing our longer-term investigations of talquetamab as we aim to develop additional options for patients with this complex blood cancer," said Sen Zhuang, vice president of clinical R&D at Janssen Research & Development.
The Phase 1 data was published in The New England Journal of Medicine.
Source: Mount Sinai, Johnson & Johnson
The side effects are due to the fact that most all these immuno drugs kill normal cells along with the cancer cells. Since myeloma is a cancer of plasma cells, it has the same antigens as many normal plasma cells, which are needed to make the molecules our immune system needs. Also, talquetamab causes taste problems, which can greatly interfere with quality of life.
The most promising myeloma drug to date is one that targets the mutations that lead to the cancer. That means there should be no normal cells attacked. This drug is about to enter Phase II testing, and I hope it works.