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Table 5. Results of Isolex 300i CD34 selection
Prince et al. 319
Hematopoietic
Preselection Postselection recovery (cycle 1)
CD34 content
Infused! cycle
of apheresis CD34 CD34 (i.e 113 total) ANC Platelets
product purity Recovery content (CD34 : >0.5X10 9
IL>50X10 9
IL
ID % Xl&lkg (%) (%) (XlCfilkg) Xl&lkg) (days) (days)
1617 3.22 3.04* 27.2 13.6 0.41 0.14 m 32|
0118 2.33 12.8 28 1 0.13 0.04 10 19
4026 1.04 8.84 81.3 39.3 3.46 1.15 10 17
4230 3.63 23.82 87.4 35.4 8.43 — — —
0637t 2.11 17.55 85.5 17.1 3.01
0.85 4.4 81.1 34.3 1.51 1.5 10 17
1050 0.23 15.3 90.4 60 9.01 3.01 9 14
1506 1.61 14.1 92.9 34.4 4.85 1.62 11 22
0220 3.1 17.43 91.3 37.4 6.9 2.3 12 15
1603 0.32 26.88 75.1 16.7 4.5 1.5 11 17
Mean 1.84 14.3 74.0 29.0 4.22 1.27 10 17
*Thawed before undergoing CD34 selection; CD34 count represents postthaw specimen;
tseparate separations on two consecutive days; ^delayed neutrophil and platelet engraft-
ment; unselected "back-up" cells used for next two cycles.
most common approach used to formulate these repetitive regimens has been to
repeat or combine recognized "single-transplant" regimens or modify existing
regimens by selective reductions in drug doses. Not unexpectedly, this has resulted
in a wide variation in toxicities observed. Conversely, arbitrary modifications of
drug dose may lead to ineffective regimens. For this reason, we decided to formally
explore the ITP drug combination in a phase I study.
Although no formal phase I studies of repetitive high-dose therapy have been
published in full, the best investigated regimen to date has been modifications
of CTCb (cyclophosphamide, thiotepa, carboplatin). Rodenhuis et al., 23
in a
phase II study, attempted to deliver three cycles of full dose CTCb (cyclophosphamide
6 g/m 2
, thiotepa 480 mg/m 2
, carboplatin 1600 mg/m 2
) with only 10 of
the 35 patients receiving three cycles of the planned therapy. Of the 10, only
four could be administered at full dose as planned. Of these four, two died of
toxicity. The same investigators administered the same drugs for three cycles at
an arbitrarily selected two-thirds dose. Fourteen of the 23 patients received all
three cycles, and the treatment was associated with mild to moderate
nonhematopoietic toxicity. 24
Shapiro et al. 25
administered even lower doses of
CTCb (cyclophosphamide 1.5 g/m 2
, thiotepa 125 mg/m 2
, carboplatin 200