A Study in Hormone Receptor-positive Metastatic Breast Carcinoma Patients to Test a New Schedule of Efti (IMP321, Eftilagimod Alpha) as Adjunctive to a Weekly Treatment Regimen of Paclitaxel

AIPAC-002 (Active Immunotherapy PAClitaxel-002): A Multicentre, Phase Ib Study to Test a New Schedule of Eftilagimod Alpha (a Soluble LAG-3 Protein) as Adjunctive to Weekly Paclitaxel in Hormone Receptor-positive Metastatic Breast Carcinoma Patients

This is a multicentre, multinational Phase Ib study in female HR+ MBC patients not receiving Her2-targeted therapy. Treatment consists of a chemo-immunotherapy phase followed by a maintenance phase. The chemo-immunotherapy phase consists of 6 cycles of 4 weeks each. During each cycle the subject will receive 80 mg/m2 paclitaxel intravenously on Day 1, 8 and 15 and 30 mg efti subcutaneously on Day 1 and 15 in a 28-day (4-week) cycle. Efti will always be given after paclitaxel. The maintenance phase comprises 6 visits with 4 weekly intervals; during each such visit 30 mg efti is given subcutaneously as monotherapy. A total of 24 subjects will be enrolled into the study. The primary goal of the study is safety and tolerability profile of efti in combination with weekly paclitaxel both given the same day in contrast to subsequent days as in the AIPAC trial.

This is a multicentre, multinational Phase Ib study in female HR+ MBC patients not receiving Her2-targeted therapy. Treatment consists of a chemo-immunotherapy phase followed by a maintenance phase. The chemo-immunotherapy phase consists of 6 cycles of 4 weeks each. During each cycle the subject will receive 80 mg/m2 paclitaxel intravenously on Day 1, 8 and 15 and 30 mg efti subcutaneously on Day 1 and 15 in a 28-day (4-week) cycle. Efti will always be given after paclitaxel. The maintenance phase comprises 6 visits with 4 weekly intervals; during each such visit 30 mg efti is given subcutaneously as monotherapy. A total of 24 subjects will be enrolled into the study. The primary goal of the study is safety and tolerability profile of efti in combination with weekly paclitaxel both given the same day in contrast to subsequent days as in the AIPAC trial.

Inclusion Criteria (selected ones):

• Metastatic oestrogen receptor positive and/or progesterone receptor positive breast adenocarcinoma, histologically proven by biopsy of the primary tumour and/or a metastasis
• Subjects who are indicated to receive first line chemotherapy with weekly paclitaxel
• ECOG performance status 0-1
• Expected survival longer than three months

Exclusion Criteria (selected ones):

• Prior chemotherapy for metastatic breast adenocarcinoma
• Disease-free interval of less than twelve months from the last dose of adjuvant chemotherapy
• Prior high-dose chemotherapy requiring hematopoietic stem cell rescue
• Inflammatory carcinoma at time of screening
• Candidate for treatment with trastuzumab (or other Her2/neu targeted agents) or endocrine based therapy according to the applicable treatment guidelines
• Systemic chemotherapy, radiation therapy or any other investigational agent within 4 weeks, endocrine therapy within 1 week or CDK4/6 inhibitors within 5 times half-life (acc. to SPC) prior to first dose of study treatment
• Symptomatic known cerebral and/or leptomeningeal metastases