IMP321 (Eftilagimod Alpha) as Adjunctive to a Standard Chemotherapy Paclitaxel Metastatic Breast Carcinoma

This is a multicentre, placebo-controlled, double-blind, 1:1 randomised Phase IIb study in female hormone receptor-positive metastatic breast cancer patients. The study comprises of two stages.

Stage 1 is the open-label, safety run-in stage consisting of cohort 1 and 2 to confirm the (RPTD) of IMP321 in combination with paclitaxel.

Stage 2 is placebo-controlled, double-blind randomisation stage, paclitaxel + IMP321 at the RPTD will be compared to paclitaxel + placebo.

Inclusion criteria

• Able to give written informed consent and to comply with the protocol
• Metastatic oestrogen receptor positive and/or progesterone receptor positive breast adenocarcinoma, histologically proven by biopsy of the primary tumour and/or metastasis
• Female of age 18 years or above
• Patients who are indicated to received first line chemotherapy with weekly paclitaxel
• Evidence of measurable disease as defined by Response Evaluation Criteria version 1.1

6 Laboratory criteria: haematology and biochemistry results within the limits normally expected for the patient population.

Exclusion criteria

• Prior chemotherapy for metastatic breast adenocarcinoma
• Disease-free interval of less than twelve months from the last dose of adjuvant chemotherapy
• Inflammatory carcinoma
• Candidate for treatment with trastuzumab (or other Her2/neu targeted agents)
• Systemic chemotherapy, radiation therapy or any other investigational agent within 4 weeks, endocrine therapy within 1 week prior to first dose of study treatment or CDK4/6 inhibitors within 5 times half-life (acc.to SPC) prior to first dose of study treatment and until completion of study treatment
• Symptomatic known cerebral and/or leptomeningeal metastases
• Serious intercurrent infection
• Evidence of severe or uncontrolled cardiac disease (NYHA III-IV) within 6 months prior to first dose of study treatment
• Active acute or chronic infection
• Active autoimmune disease requiring immunosuppressive therapy
• Previous malignancies within the last three years other than breast carcinoma
• Patients with prior organ or stem cell transplantation
• Any condition requiring continuous systemic treatment with either corticosteroids or other immunosuppressive medications within 4 weeks prior to first dose of study treatment.