DANYELZA Solution for injection Ref.[108705] Active ingredients: Naxitamab

The exposure-response relationship and time course of pharmacodynamic response for the safety and effectiveness of naxitamab-gqgk have not been fully characterized.

The geometric mean (CV%) maximum plasma concentration (C_max) of naxitamab-gqgk was 57.4 µg/mL (49%) following DANYELZA 3 mg/kg intravenous infusion over 30 minutes.

Elimination

The mean terminal half-life of naxitamab-gqgk was 8.2 days.

Metabolism

Naxitamab-gqgk is expected to be metabolized into small peptides by catabolic pathways.

Specific Populations

Population pharmacokinetic analyses suggest that age (range: 1 to 34 years), sex and race have no clinically important effect on the clearance (CL) of naxitamab-gqgk. The naxitamab-gqgk systemic exposure (AUC) at 150 mg/day (450 mg per cycle) for patients with body weight over 50 kg is not expected to differ clinically from that of the naxitamab-gqgk exposures at 3 mg/kg/day (9 mg/kg per cycle) for patients with body weight of 30-50 kg.

No animal studies have been conducted to evaluate the carcinogenic or mutagenic potential of naxitamab-gqgk.

Dedicated studies evaluating the effects of naxitamab-gqgk on fertility in animals have not been conducted.

Non-clinical studies suggest that naxitamab-gqgk-induced neuropathic pain is mediated by binding of the antibody to the GD2 antigen located on the surface of peripheral nerve fibers and myelin and subsequent induction of immune-mediated cytotoxic activity.

In a nude rat model, slight-moderate hyperplasia and erosion of the glandular mucosa of the stomach occurred, occasionally accompanied by diffuse inflammation. Complete recovery of all histopathological findings in the stomachs of male rats was observed; however, only partial recovery was observed in the stomachs of female rats during the four week off-drug period.

The efficacy of DANYELZA in combination with GM-CSF was evaluated in two open-label, single arm trials in patients with high-risk neuroblastoma with refractory or relapsed disease in the bone or bone marrow, Study 201 and Study 12-230.

Study 201

The efficacy of DANYELZA in combination with GM-CSF was evaluated in Study 201 (NCT03363373), a multicenter open-label, single arm trial, in a subpopulation of patients who had refractory or relapsed high-risk neuroblastoma in the bone or bone marrow and demonstrated a partial response, minor response, or stable disease to prior therapy. Patients with progressive disease were excluded. All patients received at least one systemic therapy to treat disease outside of the bone or bone marrow prior to enrollment. Patients received DANYELZA 9 mg/kg/cycle administered as three separate intravenous infusions of 3 mg/kg on Days 1, 3 and 5 of each cycle. Patients received GM-CSF subcutaneously at 250 µg/m²/day on Days -4 to 0 and at 500 µg/m²/day on Days 1 to 5. Preplanned radiation to the primary site was allowed.

The major efficacy outcome measure was overall response rate (ORR) according to the revised International Neuroblastoma Response Criteria (INRC), as determined by independent pathology and imaging review and confirmed by at least one subsequent assessment. An additional efficacy outcome measure was duration of response (DOR).

Of the 22 patients included in the efficacy analysis, 64% had refractory disease and 36% had relapsed disease; the median age was 5 years (range 3 to 10 years), 59% were male; 45% were White, 50% were Asian and 5% were Black. MYCN amplification was present in 14% of patients and 86% of patients were International Neuroblastoma Staging System (INSS) stage 4 at time of diagnosis. Disease sites included 59% in the bone only, 9% in bone marrow only, and 32% in both. Prior therapies included surgery (91%), chemotherapy (95%), radiation (36%), autologous stem cell transplant (ASCT) (18%), and anti-GD2 antibody treatment (18%).

Efficacy results for Study 201 are described in Table 8.

Table 8. Efficacy Results from Study 201:

CI = confidence interval
NE: not estimable.

In an exploratory analysis in the subset of patients previously treated with an anti-GD2 antibody (n=4), one patient demonstrated a confirmed complete response and no patients demonstrated a partial response.

Study 12-230

The efficacy of DANYELZA in combination with GM-CSF was evaluated in Study 12-230 (NCT01757626), a single center, open-label, single arm trial, in a subpopulation of patients who had relapsed or refractory high-risk neuroblastoma in bone or bone marrow and demonstrated a partial response, minor response, or stable disease to prior therapy. Patients with progressive disease were excluded. All patients received at least one systemic therapy to treat disease outside of the bone or bone marrow prior to enrollment. Patients were required to have received at least one dose of DANYELZA at a dose of 3 mg/kg or greater per infusion and have evaluable disease at baseline according to independent review per the revised INRC.

Patients received DANYELZA 9 mg/kg/cycle administered as three separate intravenous infusions of 3 mg/kg (on Days 1, 3 and 5) in the first week of each cycle. Patients received GM-CSF subcutaneously at 250 µg/m²/day on Days -4 to 0 and at 500 µg/m²/day on Days 1 to 5. Radiation to non-target bony lesions and soft tissue lesions was permitted at the investigator’s discretion; assessment of response excluded sites that received radiation. The major efficacy outcome measures were overall response rate (ORR) and duration of response (DOR), as determined by independent pathology and imaging review according to the revised INRC and confirmed by at least one subsequent assessment.

Of the 38 patients included in the efficacy analysis, 55% had relapsed neuroblastoma and 45% had refractory disease; 50% were male, the median age was 5 years (range 2 to 23 years), 74% were White, 8% Asian and 5% were Black, 5% Native American/American Indian/Alaska Native, 3% other races and 5% was not available. MYCN-amplification was present in 16% of patients and most patients were International Neuroblastoma Staging System (INSS) stage 4 (95%). Fifty percent (50%) of patients had disease involvement in the bone only, 11% only in bone marrow, and 39% in both. Prior therapies included surgery (100%), chemotherapy (100%), radiation (47%), autologous stem cell transplant (ASCT) (42%), and anti-GD2 antibody treatment (58%).

Efficacy results are provided in Table 9.

Table 9. Efficacy Results from Study 12-230:

CI = confidence interval
^* Overall response rate is defined as a complete or partial response according to the revised INRC (2017) that was confirmed by at least one subsequent assessment. Responses were observed in the bone, bone marrow, or both bone and bone marrow.

In an exploratory analysis in the subset of patients previously treated with an anti-GD2 antibody (n=22), the ORR was 18% (95% CI 5%, 40%), with no patients having a documented response of 6 months or greater.