The drug will be used in the treatment of relapsed or refractory multiple myeloma
The Janssen Pharmaceutical Companies of Johnson & Johnson announced initial data for the Phase 1 first-in-human dose-escalation study of talquetamab (JNJ-64407564) for the treatment of relapsed or refractory multiple myeloma. Talquetamab is a first-in-class and the only investigational bispecific antibody that targets both GPRC5D, a novel multiple myeloma target, and CD3 on T-cells. Initial results for both the subcutaneous (SC) and intravenous (IV) formulations show encouraging clinical activity against the GPRC5D target, which is highly expressed on multiple myeloma cells and associated with poor prognostic factors. At the SC recommended Phase 2 dose (RP2D), the overall response rate (ORR) was 69 per cent (9/13) and 39 per cent achieved a very good partial response (VGPR) or better.
“There is a pressing need for continued innovation of multiple myeloma treatments – particularly for patients who have relapsed on other therapies – and the results presented today for talquetamab are encouraging,” said Ajai Chari, Professor of Medicine, the Director of Clinical Research in the Multiple Myeloma Program, and the Associate Director of Clinical Research, Mount Sinai Cancer Clinical Trials Office. “The Phase 1 overall response rate and safety profile support further study of talquetamab in monotherapy and combination approaches for patients with few options for treatment.”
Investigators identified the RP2D of 405 µg/kg SC and concluded subcutaneous treatment may provide an opportunity for less frequent dosing than the intravenous formulation. A response was observed in 6/9 triple-class refractory patients and 2/2 penta-drug refractory patients. Pharmacokinetic results indicate target exposure levels at the RP2D. At the RP2D of 405 µg/kg SC, pharmacodynamic data demonstrate consistent T-cell activation, cytokine production and redistribution.
Patients received talquetamab at doses of 1–180 µg/kg with IV administration and 5–800 µg/kg for the SC formulation. Results from the Phase 1 study showed responses in patients who were treated with talquetamab across dose groups; median time to first confirmed response across all doses was one month (range, 0.2–3).
The Phase 1 study enrolled patients (n=157) with multiple myeloma who had progressed on, or could not tolerate, any available established therapies. Patients had received a median of six prior lines of treatment (range, 2-20); 87 per cent were refractory to the last line of therapy, 82 per cent were triple-class refractory, and 33 per cent were penta-drug-refractory to two or more immunomodulatory agents, two or more PIs, and an anti-CD38 therapy. The study is conducted in two parts: dose escalation (part 1) and dose expansion (part 2).
In the Phase 1 study, adverse events (AEs) at the RP2D which occurred with a Grade 3 frequency of ≥25 per cent among the SC cohort were neutropenia (42 per cent). With SC dosing, cytokine release syndrome (CRS) was observed in 64 per cent of patients and was low-grade with no Grade 3 or greater CRS events at the RP2D. CRS occurred at a median of two days after dosing, and median duration of CRS was also two days. The incidence of neurotoxicity was five per cent at the RP2D, with no patients experiencing Grade 3 or greater events with SC dosing.
“GPRC5D is a novel target in the treatment of multiple myeloma and, as a bispecific antibody that engages T-cells by also targeting CD3, talquetamab is emerging as a potential therapeutic option for heavily pretreated patients,” said Yusri Elsayed, Vice President, Global Head, Hematologic Malignancies, Janssen Research & Development. “Based on the preliminary efficacy, safety, pharmacokinetic and pharmacodynamic data presented, we are committed to fully exploring the promise of talquetamab in multiple myeloma.”
