The purpose of this clinical trial is to learn the safety and effects of the study medicine (PF-07799544) alone or in combination as a potential cancer treatment for adults with advanced solid tumors. The study will be conducted in two parts: PF-07799544 as a single agent (Phase 1a) and PF-07799544 in combination with another study medicine called PF-07799933 (Phase 1b).

Phase 1a is no longer open for enrollment. In Phase1b (noted as "this study"), we are seeking participants who have:

• a solid tumor which is metastatic or recurrent (excluding colorectal cancer)
• tumor with the mutation (abnormal gene) called "BRAF V600"
• received required prior treatment for cancer per cohort assigned.

All participants in this study will receive both study medicines. Both study medicines are tablets that are taken by mouth at home twice a day.

Participants will receive study medicines until their cancer is no longer responding, unacceptable side effects, or 2 years. Participants may continue to receive study therapy beyond 2 years. We will examine the experiences of people receiving the study medicines. This will help us determine if the study medicines are safe and effective.

Phase 1b Inclusion Criteria:

• Diagnosis of advanced/metastatic solid tumor (excluding colorectal cancer)
• Measurable disease by RECIST version 1.1
• Evidence of a BRAF V600 mutation
• Prior therapy per tumor cohort
• Adequate organ function per protocol

Phase 1b Exclusion Criteria:

• Other active malignancy within 3 years
• Presence of leptomeningeal disease
• History or current evidence of retinal vein occlusion (RVO) or history of retinal degenerative disease
• Concurrent neuromuscular disorder associated with elevated creatine kinase (CK)
• Active gastrointestinal disease as defined per protocol
• History of interstitial lung disease as defined per protocol

Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical\_trials/trial\_data\_and\_results/data\_requests.