FDA-21-RFQ-1241954-2_QA.pdf

FDA-21-RFQ-1241954-2 Solicitation Question & Responses

# Question Response 1 Could you please tell me if this is a new requirement, or if there is a current or previous contractor who has performed similar services? If available, can you please send along the incumbent contract or task order number?

No this is not a new requirement.

Similar services were previously performed by ProImmune.

. 2 When will the peptide sequences be provided to us? This will determine the project start date.

These will be provided in Nov or Dec 2021.

3 The following excerpt is from page 3 (deliverables) of the FDA-21- RFQ-1241954-2 document, T Cell Proliferation Assay:

“To be delivered within sixteen (16) weeks of order receipt unless otherwise agreed upon with the Technical POC”

Question:

A) Peptide synthesis and purification at >95% purity from the 3rd party vendor takes approximately 3-5 weeks. Will the 16 weeks count begin after receiving the synthesized peptides?

B) PBMC donations may be staggered depending on availability. On average, acquisition time for 40 donations may vary from 1-2 months and so this may affect our timeline estimation. Will the 16 weeks count begin after acquisition of the PBMCs from all 40 donors?

A) Yes we are okay with the 16 week time starting after receiving synthesized peptides.

B) No acquisition time for donors is not added on to the 16 week period for completing the task.

4 The following excerpt is from page 2, paragraph 3 of the FDA-21- RFQ-1241954-2 document, T Cell Proliferation Assay:

“For this to be done, the Contractor will need to synthesize the 20 peptides of 15 mer each, that HB has identified to be differentially presented, load then on antigen presenting cells and then expose the antigen presenting cells loaded with peptides to CD4+ T cells and monitor proliferation of the T cells.”

Question:

A) Is it okay to assume that we will only rely on innate antigen presenting cells found in each PBMCs sample and not add separate antigen presenting cells e.g. dendritic cells? In other words, we will just add peptides directly to the PBMCs.

Yes your assumption is correct.

5 Assay design:

The following assay design is based on the information provided in the FDA-21-RFQ-1241954-2 document, T Cell Proliferation Assay solicitation:

Assumptions: - The peptides will be added directly to the PBMCs without using extra antigen presenting cells (APCs)

- Each 96 well plate will have 60 tests (inner wells only)

Yes the assay design is adequate.

FDA-21-RFQ-1241954-2 Solicitation Question & Responses

- Each plate will have one set of controls as described in the table below

Test for one donor sample/one peptide pair:

Test Iterations Name PBMCs + CFSE + peptide

X6 Main test

PBMCs + peptide X3 Control PBMCs + CFSE X3 Control PBMCs + CFSE + control peptide A

X3 Control

PBMCs + CFSE + control peptide B

X3 Control

PBMCs + CFSE + control whole protein A

X3 Control

PBMCs + CFSE + control whole protein B

X3 Control

Based on this design, 40 donor samples and 20 peptides will require a total of 9,600 tests performed using 160 plates (96 well plates).

Question:

Does this assay design cover all the required parameters?