Inclusion Criteria:

* Locally-advanced or metastatic malignancy with an NTRK1, NTRK2, or NTRK3 gene fusion, identified through molecular assays as routinely performed at Clinical Laboratory Improvement Amendments (CLIA) or other similarly-certified laboratories.
* Subjects who have received prior standard therapy appropriate for their tumor type and stage of disease, or who have no satisfactory alternative treatments and in the opinion of the Investigator, would be unlikely to tolerate or derive clinically meaningful benefit from appropriate standard of care therapy.
* Subjects must have at least one measurable lesion as defined by RECIST v1.1. Subjects with solid tumors without RECIST v1.1 measurable disease (e.g., evaluable disease only) had been eligible for enrollment to Cohort 8 as per protocol versions 1.0 - 8.0, regardless of tumor type. Subjects with primary CNS tumors should meet the following criteria

1. Have received prior treatment including radiation and/or chemotherapy, with radiation completed \> 12 weeks prior to C1D1 of therapy, as recommended or appropriate for that CNS tumor type.
2. Have ≥ 1 site of bi-dimensionally measurable disease (confirmed by magnetic resonance imaging \[MRI\] and evaluable by RANO criteria), with the size of at least one of the measurable lesions ≥ 1 cm in each dimension and noted on more than one imaging slice.
3. Imaging study performed within 28 days before enrollment. If on steroid therapy, the dose must be stable for at least 7 days immediately before and during the imaging study.
4. Must be neurologically stable based on stable neurologic exam for 7 days prior to enrollment.

For subjects eligible for enrollment to bone health cohort, inclusion criterion 3 is modified as the following:
5. Subjects must have at least one lesion at baseline (measurable or non-measurable as defined by RECIST v1.1 or RANO criteria, as appropriate to tumor type).
6. Subjects with primary CNS tumors must be neurologically stable based on stable neurologic exam for 7 days prior to enrollment.
* Performance Status: Eastern Cooperative Oncology Group (ECOG) score ≤ 3 If enrolled with primary CNS tumor to be assessed by RANO, Karnofsky Performance Score (KPS) ≥50%
* Tumor tissue before treatment (mandatory). If neither fresh tissue can be obtained nor archival tissue is available patients might be enrolled after consultation with the sponsor.
* Willingness of men and women of reproductive potential to use double effective birth control methods, defined as one used by the subject and another by his/her partner, for the duration of treatment and for 1 month following study completion.
* For subjects eligible for enrollment to bone health cohort only: life expectancy of at least 6 months, based on investigator assessment.

Exclusion Criteria:

* Prior progression while receiving approved or investigational tyrosine kinase inhibitors targeting tropomyosin receptor kinase (TRK). Subjects who received less than 28 days of treatment and discontinued because of intolerance or toxicity are eligible.
* Symptomatic or unstable brain metastases. (Note: Subjects with asymptomatic brain metastases are eligible to participate in the study.) Subjects with primary central nervous system (CNS) tumors are eligible.
* Pregnancy or lactation.
* Active uncontrolled systemic bacterial, viral, or fungal infection Common Terminology Criteria for Adverse Events(CTCAE) grade ≥ 2; unstable cardiovascular disease, or other systemic disease that would limit compliance with study procedures.
* Unstable cardiovascular disease is defined as:

* In adults, persistently uncontrolled hypertension defined as systolic blood pressure (BP) \> 150 mmHg and/or diastolic BP \> 100 mmHg despite antihypertensive therapy.
* Myocardial infarction within 3 months of screening.
* Stroke within 3 months of screening.