Inclusion Criteria:

1. Patients with anatomopathological diagnosis of metastatic or locally advanced
unresectable soft tissue sarcoma (STS). Patients with the following STS types will be
excluded: chondrosarcoma, Ewing's sarcoma and embryonal or alveolar rhabdomyosarcoma.
In phase 1 it will be allowed to include patients having other types of advanced
cancer which are resistant to the standard treatment and can benefit from any of the
study drugs.

2. Prior treatment with chemotherapy including doxorubicin and ifosfamide, or
contraindication for its administration. The previous treatment with gemcitabine or
inhibitors of mTOR is not allowed.

3. Age ≥ 18 y ≤ 70 years.

4. ECOG performance status: 0 - 2. In Phase 1 only patients with ECOG 0-1 will be
enrolled.

5. Disease measurable according to RECIST criteria. Proven relapsed disease.

6. Adequate bone marrow function, defined as neutrophil count ≥ 1.500/mm^3 and platelets
≥ 100.000/mm^3.

7. Adequate renal and hepatic function , defined as calculated creatinine clearance ≥ 60
ml/min, creatinine, total bilirubin, AST and/or ALT ≤ 1,5 times the upper limit of
normal (ULN).

8. Informed consent form signed by the patient prior to the beginning of the treatment.

Exclusion Criteria:

1. History of previous cancer diagnosed or treated in the past 5 years except basal cell
carcinoma, cervical carcinoma in situ or superficial bladder cancer.

2. Presence of brain metastases.

3. Active infection or other severe concomitant diseases.

4. Concurrent treatment with other experimental drugs within 30 days prior to study
entry.

5. Pregnancy or breastfeeding.