RATIONALE: Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die. Combining more than one drug may kill more tumor cells.

PURPOSE: Phase I trial to study the effectiveness of bryostatin 1 plus gemcitabine in treating patients who have advanced cancer that has not responded to previous treatment.

OBJECTIVES:

• Determine the maximum tolerated dose of gemcitabine when given concurrently with bryostatin 1 to patients with advanced refractory cancer.
• Access the pattern of toxicity of this drug regimen in this patient population.
• Determine the objective response rate, duration of response, and overall survival in patients treated with this drug regimen.
• Determine the influence of bryostatin 1 on the pharmacokinetics of gemcitabine.

OUTLINE: This is a dose escalation study.

Patients receive gemcitabine IV over 30 minutes, immediately followed by bryostatin 1 IV over 24 hours, weekly for 3 weeks (days 1, 8, and 15). Treatment repeats every 28 days in the absence of unacceptable toxicity or disease progression.

Cohorts of 3-6 patients receive escalating doses of gemcitabine and bryostatin 1 until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose preceding that at which 2 of 6 patients experience dose limiting toxic effects.

PROJECTED ACCRUAL: Approximately 2-3 patients per month will be accrued for this study.

DISEASE CHARACTERISTICS:

• Histologically or cytologically proven advanced cancer (except hematological cancers) for which there is no standard therapy or have failed standard therapies
• Measurable or evaluable disease
• Clinically controlled brain metastases allowed

PATIENT CHARACTERISTICS:

Age:

• 18 and over

Performance status:

• SWOG 0-2

Life expectancy:

• At least 3 months

Hematopoietic:

• Hemoglobin at least 8.0 g/dL
• Absolute neutrophil count at least 1,500/mm^3
• Platelet count at least 100,000/mm^3

Hepatic:

• Bilirubin no greater than 1.5 times upper limit of normal (ULN) (elevated bilirubin due to Gilbert's syndrome allowed if direct bilirubin normal)
• AST less than 2.5 times ULN

Renal:

• Creatinine normal

Cardiovascular:

• No active cardiac disease

Other:

• Not pregnant or nursing
• Fertile patients must use effective contraception
• No concurrent bacterial infection requiring antibiotics
• No serious concurrent medical condition

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• No concurrent immunotherapy

Chemotherapy:

• At least 3 weeks since systemic cytotoxic chemotherapy (including gemcitabine) and recovered
• No other concurrent chemotherapy

Endocrine therapy:

• Prior hormonal therapy allowed
• No concurrent hormonal therapy (excluding contraceptives, appetite stimulants, or replacement steroids)

Radiotherapy:

• At least 3 weeks since radiotherapy to large areas of active bone marrow and recovered
• No concurrent radiotherapy

Surgery:

• Recovered from prior major surgery

Other:

• No concurrent antiviral nucleosides
• At least 1 month since prior investigational agents
• No other concurrent experimental medications