A Study to Learn About the Study Medicine Called PF-07799933 in People With Advanced Solid Tumors With BRAF Alterations.

This study is seeking participants who meet the following key eligibility criteria:

Inclusion Criteria:

* Diagnosis of advanced/metastatic solid tumor including primary brain tumor.
* Qualifying BRAF alteration (V600 or non-V600 Class II/Class III BRAF alteration), in tumor tissue and/or blood (ie circulating tumor deoxyribonucleic acid \[DNA\], or ctDNA).
* Disease progressed during/following last prior treatment and no satisfactory alternative treatment options (Part 1, Part 2 (doublet), and Part 3 (cohorts 2, 3, 6, 7)).
* Tumor specific cohorts (melanoma, colorectal cancer) must have received specific prior approved therapies
* Part 3 (Cohort 1) (BRAF V600 mutant melanoma): Prior BRAF V600 inhibitor therapy required, prior MEK inhibitor therapy required, and immune checkpoint inhibitor therapy required.
* Part 3 (Cohort 4) (BRAF V600E CRC): Minimum of 2 cycles of prior 5-FU based chemotherapy required. No prior BRAF inhibitor/EGFR inhibitor allowed. Participants with MSI-H/dMMR mCRC should receive prior immune checkpoint inhibitor therapy.
* Part 3 (Cohort 5) (BRAF V600E CRC): No more than 2 cycles of prior 5-FU based chemotherapy allowed. No prior BRAF inhibitor/EGFR inhibitors allowed. Participants with MSI-H/dMMR mCRC should receive prior immune checkpoint inhibitor therapy.

Exclusion Criteria:

* Brain metastasis larger than 4 cm
* Systemic anti-cancer therapy or small molecule therapeutics ongoing at the start of study treatment.
* History or current evidence of retinal vein occlusion (RVO) or current risk factors for RVO; history of retinal degenerative disease.
* Concurrent neuromuscular disorder associated with elevated creatine kinase (CK).