Pharmacokinetic Study of Pembrolizumab and Its Impact on Immunity and the Tumor Microenvironment, Which May Explain the Efficacy of Post-immunotherapy Chemotherapy.

Inclusion Criteria

• •\- Patients over 18 years of age
• •\- Patients diagnosed with :
• •1. Non-small cell lung cancer (NSCLC), including adenocarcinoma and squamous cell carcinoma.
• •2. Head and neck squamous cell carcinoma, p16-negative for oropharyngeal tumors.
• •* Recurrent and/or metastatic tumor not amenable to curative locoregional treatment.
• •* Disease progression under Pembrolizumab immunotherapy, administered at the standard dose of 200 mg every 3 weeks, as first-line treatment for metastatic disease, regardless of the number of cycles received, either as monotherapy or in combination with chemotherapy, as defined below:
• •• For pulmonary adenocarcinomas: i. First-line treatment with Pembrolizumab in combination with a platinum agent (Carboplatin or Cisplatin) and Pemetrexed
• •ii. Maintenance therapy with Pembrolizumab, with or without Pemetrexed.
• •• For pulmonary squamous cell carcinomas: i. First-line treatment with Pembrolizumab in combination with a platinum agent (Carboplatin) and Paclitaxel
• •+/- ii. Maintenance therapy with Pembrolizumab alone.
• •• For head and neck squamous cell carcinomas : i. First-line treatment with Pembrolizumab in combination with a platinum agent (Carboplatin or Cisplatin) ± 5-Fluorouracil (5-FU) or Paclitaxel
• •+/- ii. Maintenance therapy with Pembrolizumab alone.
• •* Eligibility for salvage chemotherapy within standard care:
• •• For pulmonary adenocarcinomas: weekly Paclitaxel, with or without Bevacizumab.
• •* For pulmonary squamous cell carcinomas: Gemcitabine monotherapy.
• •* For head and neck squamous cell carcinomas: weekly Paclitaxel and/or Cetuximab. Standard salvage chemotherapy may be initiated between Day 18 and Day 35 following the last Pembrolizumab injection, at standard doses.
• •* Measurable disease according to RECIST 1.1 criteria.
• •* Performance status (PS) 0 to 2.
• •* Baseline laboratory results meeting the usual criteria permitting initiation of salvage chemotherapy.
• •* Patients who has voluntarily agreed to participate in the study (including additional blood sampling) and has signed the informed consent form.
• •* For the subpopulation with accessible tissue biopsy:
• •* Patient agrees to undergo biopsy,
• •* INR \< 1.5, Platelets \> 50000/μL.
• •* Patients covered by a social security health insurance scheme.