Page 68 - 2020_02-Haematologica-web

I. Yakoub-Agha et al.
Only one of the commercial CAR T-cell manufacturers – Novartis – currently requires cryopreservation of the mononuclear cells on site. It is stipulated that the white blood cell count should be adjusted to 1.0 (0.5-2.0) x108/mL, that an approved (approved by the company and local regulators) cryoprotectant be added slowly and that the cells be frozen in controlled-rate freezers prior to stor- age in vapor phase liquid nitrogen. To produce KymriahTM, Novartis will accept cells that have been harvested within the preceding 18 months and cryopreserved with appro- priate quality management surveillance. Whether autolo- gous blood mononuclear cells intended for CAR T-cell manufacturing should be prospectively collected and cry- opreserved in selected patients at high risk of relapse is already under debate. The other commercial manufactur- ers will collect fresh apheresis product packed in their own specified shipping containers. Until shipping, these apheresis products are stored refrigerated (2-8°C).
Manufacturers’ requirements for quality control are cur- rently very limited and may be exceeded by local require- ments. There may also be differences between FDA and
EMA requirements.22 Accredited and validated testing methods must be used. In addition to testing for infectious disease markers in peripheral blood samples on the day of collection, reasonable quality control should include steril- ity testing as well as some hemocytometric parameters (white blood cell count, hematocrit, CD3+, and viable CD45+ counts). Sampling of the collected cell product must follow the manufacturer’s requirements so as not to compromise downstream processing steps, while also complying with local manufacturing authorizations.
Depending on the disease burden, it may be possible to arrange for leukapheresis before starting salvage chemotherapy to treat disease relapse. There is evidence that cumulative chemotherapy exposure adversely affects the quality of circulating T cells. Although apheresis can be performed in patients with absolute lymphocyte counts as low as 0.1x109/L, the likelihood of reaching the target number of autologous lymphocytes and successful- ly manufacturing the drug product is higher in individuals with absolute lymphocyte counts exceeding 0.5x109/L. In addition, the choice of salvage therapy (chemotherapy,
Table 3. Checklist prior to apheresis. Prior to apheresis
ECOG PS score
Days after last chemotherapy
Days off corticosteroids
Hepatitis B, hepatitis C, HIV, syphilis, and HTLV
C-reactive protein
Standard electrolytes and renal function
Hemoglobin
Absolute neutrophil count
Absolute lymphocyte count
Platelet count Full blood count
Trials/SPC
Not specified
Three (KymriahTM)
to 7 (YescartaTM) days
off or on no more than prednisolone 5 mg equivalent
Mandatory for all trials
EBMT recommendations
ECOG PS score ≤2
Allow for recovery from cytotoxic
chemotherapy
Ideally, 7 days to minimize effect on lymphocyte collection
Mandatory blood tests
Mandatory in some countries.
To be done within 30 days of leukapheresis and results must be available at the time of collection and shipment
Blood tests to ascertain suitability for apheresis
Recommended to assess for ongoing infection
Required
Comment
At discretion of apheresis practitioner
Need for marrow recovery from prior
chemotherapy
A shorter period of as few as 3 days was considered acceptable
by Kansagra et al.12 Physiological replacement doses of hydrocortisone permitted
Only serological testing is required; nucleic acid testing is not necessary if all serological testing is negative
In patients with active infection, eligibility for apheresis will need to be decided on
a case-by-case basis
Apheresis may predispose to electrolyte imbalance
and limited fluid tolerance
To establish a good interface during collection
Consistent with recovery from
prior chemotherapy
Higher count required in small children.
Of note, 0.2x109/L CD3+ count is the minimum threshold
Transfuse as required Apheresis can remove more than
30% of circulating platelets
Blood values required for optimal apheresis performance
Hemoglobin >80 g/L Hematocrit >0.24
>1.0x109/L
> 0.2x109/L*
> 30x109/L
To be repeated at the end of
apheresis procedure
SPC: summary of product characteristics; EBMT: European Society for Blood and Marrow Transplantation; ECOG PS: Eastern Cooperative Oncology Group Performance Status; HIV: human immunodeficiency virus; HTLV: human T-lymphotropic virus. *This threshold specifically applies to count recovery following corticosteroid therapy where an absolute lymphocyte count >0.2 is a surrogate marker of corticosteroid washout.
302
haematologica | 2020; 105(2)