The study hypotheses is that the introduction of dose escalated thiotepa, in substitution to busulfan or melphalan, will reduce toxicity after allogeneic transplantation while improving disease eradication in patients with lymphoid malignancies not eligible for standard transplantation.

Inclusion Criteria:

1. Age less than physiologic 68 years.

2. Patients with MM, NHL, HL and CLL with an indication for allogeneic transplantation as follows:

   1. MM; patients relapsing after autologous transplant or with high-risk cytogenetic abnormalities
   2. Aggressive lymphoma and Hodgkin lymphoma; relapse after autologous transplants
   3. Follicular lymphoma; failure of at least one prior regimen
   4. CLL; failure of prior therapy which includes Fludarabine combinations or 17p- cytogenetic abnormality

3. Patients must have an HLA matched related or unrelated donor willing to donate either peripheral blood stem cells or bone marrow. Matching is based on high-resolution class I (HLA-A, -B, -C) and class II (HLA-DRB1, -DQB) typing. The goal is to transplant > 3 x 106 CD34+ cells per kg body weight of the recipient

4. Patients must sign written informed consent.

5. Adequate birth control in fertile patients.

Exclusion Criteria:

1. Bilirubin > 3.0 mg/dl, transaminases > 3 times upper normal limit
2. Creatinine > 2.0 mg/dl
3. ECOG-Performance status > 2
4. Uncontrolled infection
5. Pregnancy or lactation
6. Abnormal lung diffusion capacity (DLCO < 40% predicted)
7. Severe cardiovascular disease
8. CNS disease involvement
9. Pleural effusion or ascites > 1 liter
10. Known hypersensitivity to Fludarabine or treosulfan
11. Psychiatric conditions/disease that impair the ability to give informed consent or to adequately co-operate