Inclusion Criteria:

          1. For Part 1A: Histological or cytological diagnosis of a solid tumor that is
             advanced/metastatic, patients are intolerant to standard treatment, resistant to
             standard therapy or for which no standard therapy is available for the following tumor
             types:

             Breast cancer; Prostate cancer (mCRPC testosterone less than 50 ng/dL); Squamous cell
             cancer of the head and neck; Melanoma; Mesothelioma; Pancreatic cancer; Colorectal
             cancer; Renal cell carcinoma; Hepatocellular cancer.

          2. For Part 1B, Part 2A, and Part 2B:

               -  Histologically or cytologically confirmed prostate adenocarcinoma metastatic
                  disease.

               -  Effective castration with serum testosterone levels 0.5 ng/mL (1.7 nmol/L).

               -  Having received 3 or more cycles of prior docetaxel therapy (before or after
                  abiraterone).

               -  Having PD while receiving abiraterone acetate within 12 months of abiraterone
                  treatment initiation.

               -  Progressive disease (PD) by:

                    1. Progression in measurable disease per RECIST 1.1 criteria. Patient with
                       measurable disease must have at least 1 lesion that can be accurately
                       measured in at least 1 dimension (longest diameter to be recorded). Each
                       lesion must be at least 10 mm when measured by computed tomography (CT) (CT
                       scan thickness no greater than 5 mm) or magnetic resonance imaging (MRI).
                       Lymph nodes should be greater than or equal to 15 mm in short axis. As
                       defined by PCWG2, if lymph node metastasis is the only evidence of
                       metastasis, it must be greater than or equal to 20 mm in diameter when
                       measured by spiral CT or MRI. Previously irradiated lesions, primary
                       prostate lesion, and bone lesions will be considered non-measurable disease,
                       or

                    2. Appearance of 2 or more new bone lesions (PCWG2). They must be confirmed by
                       other imaging modalities (CT; MRI) if ambiguous results, or

                    3. Rising PSA defined (PCWG2) as at least 2 consecutive rises in PSA to be
                       documented over a reference value (measure 1) taken at least 1 week apart. •
                       Prior abiraterone acetate must be stopped at least 2 weeks before study
                       treatment.

          3. Patients must have recently obtained archival tumor tissue available for submission to
             the sponsor (except for Part 2A - monotherapy dose expansion). Patients enrolled in
             Part 1 and Part 2 should have access to their archival formalin-fixed
             paraffin-embedded material, collected within 6 months of screening, containing tumor
             that is of diagnostic quality and representative of their diagnosed malignancy or
             whenever possible, consent to undergo a biopsy during screening. The sponsor should be
             contacted if obtaining a new biopsy is not medically feasible for approval to enroll,
             prior to initiating screening activities.

          4. Patients entering the study in the subgroup(s) requiring mandatory pre- and on
             treatment tumor biopsies in Part 2A and 2B must have a tumor amenable to biopsy and
             consent to these planned biopsy procedures. The sponsor should be contacted if
             obtaining a pre-treatment and on treatment biopsies is not medically feasible for
             approval to enroll, prior to initiating screening activities.

          5. Age 18 years or older

          6. Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) 0 or 1.

          7. Adequate bone marrow function (see Appendix 3), including:

               -  Absolute Neutrophil Count (ANC) greater than or equal to 1,500/mm3;

               -  Platelets greater than or equal to 100,000/mm3;

               -  Hemoglobin greater than or equal to 9 g/dL.

          8. Adequate renal function, including serum creatinine less than or equal to 1.5 x upper
             limit of normal (ULN) or estimated creatinine clearance greater than or equal to 60
             mL/min as calculated using the method standard for the institution. In equivocal
             cases, a 24 hour urine collection test can be used to estimate the creatinine
             clearance more accurately. In Part 2: Serum creatinine of less than or equal to 3.0 x
             upper limit of normal.

          9. Adequate liver function, including:

               -  Total serum bilirubin less than or equal to 0.5 x ULN unless the patient has
                  documented Gilbert syndrome;

               -  Aspartate and alanine aminotransferase (AST and ALT) less than or equal to 2.5 x
                  ULN less than or equal to 5.0 x ULN if there is liver involvement by the tumor;

               -  Alkaline phosphatase less than or equal 2.5 x ULN less than or equal to 5 x ULN
                  in case of bone metastasis).

         10. Serum phosphate within normal range (if abnormal, must be nonclinically significant
             per the Investigator and approval for patient inclusion after agreement from sponsor.

         11. Resolved acute effects of any prior therapy to baseline severity or CTCAE Grade 1
             except for alopecia and those listed in the specific exclusion criteria.

         12. For Part 1A monotherapy dose escalation: serum pregnancy test (for females of
             childbearing potential) negative at screening.

         13. For Part 1A monotherapy dose escalation: female patients of nonchildbearing potential
             must meet at least 1 of the following criteria:

               -  Achieved postmenopausal status, defined as follows: cessation of regular menses
                  for at least 12 consecutive months with no alternative pathological or
                  physiological cause; and must have a serum follicle stimulating hormone level
                  confirming the postmenopausal state;

               -  Have undergone a documented hysterectomy and/or bilateral oophorectomy;

               -  Have medically confirmed ovarian failure. All other female patients (including
                  female patients with tubal ligations) are considered to be of childbearing
                  potential.

         14. Evidence of a personally signed and dated informed consent document indicating that
             the patient has been informed of all pertinent aspects of the study.

         15. Willing and able to comply with scheduled visits, treatment plan, laboratory tests,
             and other procedures.

        Exclusion Criteria

        Patients with any of the characteristics/conditions listed below will not be included in
        the study:

        Any labs may be repeated for confirmation. Only the lab result requiring confirmation must
        be repeated, not the entire panel.

          1. For Parts 1B, 2A, and 2B:

               -  Prior chemotherapy other than docetaxel for prostate cancer, except estramustine,
                  adjuvant/neoadjuvant treatment completed more than 3 years ago;

               -  Less than 28 days elapsed from prior treatment with chemotherapy, immunotherapy,
                  radiotherapy, or surgery to the time of study enrollment.

          2. Central Nervous System (CNS) metastases, carcinomatous meningitis, or leptomeningeal
             disease as indicated by baseline brain MRI (or CT with contrast if MRI is medically
             contraindicated), clinical symptoms, cerebral edema, and/or progressive growth. If
             contrast is medically contraindicated, a non-contrast CT scan may be performed.

          3. Patients with a history of CNS metastases or cord compression.

          4. Liver metastases at baseline as evidenced by CT scan or MRI that may be at risk for
             bleeding, such as those that are greater than 1 cm,

          5. Patients with advanced/metastatic, symptomatic, visceral spread, that are at risk of
             life threatening complications in the short term (including patients with massive
             uncontrolled effusions [pleural, pericardial, peritoneal], pulmonary lymphangitis, and
             over 50% liver involvement). Note: Patients with indwelling catheter for drainage, or
             requirement for drainage no more frequently than monthly will be allowed.

          6. Any other active malignancy within 3 years prior to study entry, except for adequately
             treated basal cell or squamous cell skin cancer, or carcinoma in situ.

          7. Patients with a history of clinically significant tumor bleeding (except for bleeding
             in a post-operative setting), coagulopathy or arterio-venous malformations (AVM) or
             aneurysms in the CNS, liver, lung or other major organ of the body. Patients with
             known Osler-Weber-Rendu disease, Hemophilia A, Hemophilia B (Christmas Disease), Von
             Willibrand's Disease, Factor 13 deficiency and Factor 7 deficiency, antibodies to
             Factors 8 and 7, history of other bleeding diatheses and abnormal INR values.

          8. Evidence of a tumor that compresses or invades major blood vessels or tumor cavitation
             that in the opinion of the investigator is likely to bleed.

          9. Major surgery within 4 weeks prior to first dose.

         10. Prior organ transplantation including heart and allogeneic stem cell transplantation.

         11. Radiation therapy within 4 weeks prior to study entry. Note: Patients who have
             received radiotherapy must have recovered from any reversible side effects, such as
             nausea and vomiting.

         12. Last anti cancer therapy including investigational drug(s) within 28 days (or 5
             half-lives, whichever is shorter) prior to study entry excluding hormonal therapy.

         13. Active and clinically significant bacterial, fungal, or viral infection, including
             known hepatitis B virus (HBV), known hepatitis C virus (HCV), known human
             immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS) related
             illness. In equivocal cases, with positive serology, those patients with a negative
             viral load are potentially eligible provided the other entry criteria are met. Note:
             Inclusion of patients with well controlled HIV, HBV or HCV can be discussed with
             sponsor on a case by case basis.

             • COVID-19/SARS-CoV2: Refer to Appendix 8 for further information.

         14. Any of the following in the previous 6 months: myocardial infarction, congenital long
             QT syndrome, Torsades de pointes, arrhythmias (including sustained ventricular
             tachyarrhythmia and ventricular fibrillation), right bundle branch block and left
             anterior hemiblock (bifascicular block), unstable angina, coronary/peripheral artery
             bypass graft, symptomatic congestive heart failure (New York Heart Association class
             III or IV), cerebrovascular accident, transient ischemic attack, or symptomatic
             pulmonary embolism; deep venous thrombosis (DVT); arterial occlusive disease; ongoing
             cardiac dysrhythmias of National Cancer Institute (NCI) CTCAE Grade 2 or higher ,
             atrial fibrillation of any grade that is uncontrolled, or QTcF interval greater than
             470 msec at screening. Note: There is an exception where a cardiac rhythm
             device/pacemaker is fitted and results in QTcF greater than 470 msec.

         15. Anticoagulation therapy with heparin, low molecular weight heparin, vitamin K
             antagonists, anti-platelet agents, or factor Xa inhibitors throughout the study and
             for at least 28 days post the last dose of study treatment. (If anticoagulation
             therapy is medically indicated on trial, patients should stop treatment with
             PF-06952229. For those requiring temporary anticoagulant therapy, resumption of
             PF-06952229 treatment may be permitted after discussion with the Sponsor. In any other
             case, study treatment should be permanently discontinued, and the patient should enter
             the follow-up portion of the trial.)

         16. Moderate or severe heart valve function defect including moderate or severe valve
             stenosis or regurgitation.

         17. Evidence or history of septal aneurysm, other heart aneurysm, or any aneurysm of the
             major vessels.

         18. Grade 3 or higher cardiac troponin I at baseline.

         19. Left ventricular ejection fraction (LVEF) of less than or equal to 50% or significant
             valvular regurgitation.

         20. Hypertension that cannot be controlled by medications (greater than 150/90 mmHg
             despite optimal medical therapy) or requiring more than 2 medications for adequate
             control.

         21. Clinically significant non healing or healing wounds.

         22. For patients entering the combination with enzalutamide arm, history of seizures other
             than isolated febrile seizure in childhood.

         23. Has a history of a cerebrovascular accident or transient ischemic attack less than 6
             months ago.

         24. Known or suspected hypersensitivity to active ingredient/excipients of PF 06952229 or
             enzalutamide.

         25. Other acute or chronic medical or psychiatric condition, including recent (within the
             past year) or active suicidal ideation or behavior or laboratory abnormality that may
             increase the risk associated with study participation or investigational product
             administration or may interfere with the interpretation of study results and, in the
             judgment of the investigator, would make the patient inappropriate for entry into this
             study.

         26. Investigator site staff members directly involved in the conduct of the study and
             their family members, site staff members otherwise supervised by the investigator, or
             patients who are Pfizer employees, including their family members, directly involved
             in the conduct of the study.

         27. For Part 1A Monotherapy Dose Escalation: Pregnant female patients; breastfeeding
             female patients; fertile male patients and female patients of childbearing potential
             who are unwilling or unable to use 2 highly effective methods of contraception as
             outlined in this protocol for the duration of the study and for at least 28 days after
             the last dose of investigational product.

         28. For Part 1B Combination Dose Escalation, Part 2A Monotherapy Expansion, and Part 2B
             Combination Dose Expansion: fertile male patients and female partners of childbearing
             potential who are unwilling or unable to use 2 highly effective methods of
             contraception as outlined in this protocol for the duration of the study and for at
             least 28 days after the last dose for monotherapy (Part 2A) or for at least 3 months
             after the last dose for combination therapy (Part 1B and Part 2B).

         29. Inability to consume or absorb study drug, including but not limited to:

             • Active inflammatory gastrointestinal (GI) disease, known diverticular disease or
             previous gastric resection or lap band surgery. Impairment of gastro intestinal
             function or GI disease that may significantly alter the absorption of PF 06952229,
             such as history of GI surgery with may result in intestinal blind loops and patients
             with clinically significant gastroparesis, short bowel syndrome, unresolved nausea,
             vomiting, active inflammatory bowel disease or diarrhea of CTCAE Grade greater than 1.

         30. Current use or anticipated need for food or drugs that are known strong and moderate
             CYP3A4/5 inhibitors, including their administration within 10 days or 5 half lives of
             the CYP3A4/5 inhibitor, whichever is longer, prior to first dose of investigational
             product.

         31. Current use or anticipated need for drugs that are known strong and moderate CYP3A4/5
             inducers, including their administration within 10 days or 5 half lives of the
             CYP3A4/5 inducer, whichever is longer, prior to the first dose of investigational
             product (See Section 5.7).

         32. Have initiated bisphosphonates or approved receptor activator of nuclear factor kappa
             B ligand (RANK L) targeted agents (for example, denosumab) less than 14 days prior to
             study entry, unless there is agreement with the medical monitor.

         33. Active, known suspect suspected autoimmune diseases including inflammatory bowel
             disease (including ulcerative colitis and Crohn's disease), rheumatoid arthritis,
             systemic progressive sclerosis, systemic lupus erythematosus (SLE), autoimmune
             vasculitis (eg, Wegener's Granulomatosis), CNS or motor neuropathy considered to be of
             autoimmune origin (eg, Gullian Barre Syndrome, Myasthenia Gravis, Multiple Sclerosis).